Sensor system with asynchronous data transmission

Abstract

The present disclosure relates to a sensor system (100) with asynchronous data transmission, where the sensor system (100) has at least two sensors (101, 102, 103), where each sensor has a first I / O pin (101IN, 102IN, 103IN) and a second I / O pin (101OUT, 102OUT, 103OUT). The sensor system (100) further has: a microcontroller (110) having a transmission pin (110Tx) and a reception pin (110Rx); and a single-wire data line (120) by means of which the microcontroller (110) can communicate with the individual sensors (101, 102, 103) via an asynchronous data protocol. The single-wire data line (120) extends between the transmitting pin (110Tx) and the receiving pin (110Rx) of the microcontroller (110), and the individual sensors (101, 102, 103) are arranged in a daisy chain (130) and are sequentially joined into the single-wire data line (120).

Description

Technical Field

[0001] This disclosure relates to a sensor system having a microcontroller and at least two sensors, wherein communication between them is carried out by means of asynchronous data transmission over a single data line. The concept described herein can be, for example, an extension of the Universal Asynchronous Receiver Transmitter (UART) protocol. Background Technology

[0002] In electronic components, such as sensors, the current technological trend is toward ever-increasing miniaturization, resulting in fewer and fewer available package solder joints. Thus, for example, a sensor package may be manufactured with only four solder joints. One solder joint is used to supply voltage, and another is connected to ground. Therefore, only two solder joints remain as I / O joints for data transmission. However, this presents a problem if multiple sensors need to communicate with each other within a sensor system.

[0003] The solution to this is the so-called Power Over Bus (POB). However, this requires expensive transmitters. Other existing solutions or bus systems require initial initialization and / or addressing of the sensors so that they can communicate with each other. To avoid the complexity of bus systems, especially in simple sensor systems, a so-called single-wire communication system is used, in which multiple sensors are connected to each other on the same single wire. An example of this is I... 2 C-bus or single-wire or single-line bus.

[0004] These mostly bidirectional single-wire communication systems are typically based on open-drain circuits with integrated pull-up resistors. However, this design results in a relatively slow baud rate of approximately 115.4 kBd, which quickly becomes critical, especially in real-time sensor systems, such as ABS sensors. Open-drain circuits with integrated pull-up resistors are also disadvantageous in that the rising edge is flattened due to its inherent low-pass properties, meaning the signal quality at the rising edge is worse than, for example, in a push-pull configuration.

[0005] Push-pull configurations are therefore preferred because continuously manipulating the push-pull outputs (high or low) provides a better solution, which involves the edges of the resulting digital output signal. However, in a push-pull configuration, it is not possible to connect multiple devices together in a single-wire bus topology compared to an open-drain configuration. Therefore, push-pull configurations are most frequently used in interfaces with unidirectional lines, meaning that data transmission occurs in only one direction on a single wire. Examples of this are SPI (Serial Peripheral Interface) or UART (Universal Asynchronous Receiver Transmitter) interfaces.

[0006] Therefore, it is desirable to improve existing sensor systems in the following way: multiple sensors can communicate with each other via a single wire without the disadvantages discussed above. In particular, it is desirable to achieve simple and cost-effective sensor communication over a single data line without requiring prior initialization of individual sensors, and with significantly higher baud rates. Summary of the Invention

[0007] This can be achieved using a sensor system with asynchronous data transmission based on the innovative concept described herein. The innovative sensor system specifically features: at least two sensors, each having a first I / O pin and a second I / O pin; and a microcontroller having a transmit pin (Tx) and a receive pin (Rx). The sensor system also has a single-wire data line through which the microcontroller can communicate with the individual sensors via an asynchronous data protocol. The single-wire data line extends between the transmit pin (Tx) and the receive pin (Rx) of the microcontroller. The individual sensors are arranged in a so-called daisy chain and sequentially coupled to the single-wire data line.

[0008] Further features and advantages of the invention will become apparent to those skilled in the art upon reading the following detailed description and observing the accompanying drawings. Attached Figure Description

[0009] This disclosure is illustrated exemplary and unrestricted in the accompanying drawings, wherein the same reference numerals refer to similar or identical elements. Elements in the drawings are not necessarily depicted to scale. Features of different illustrated examples may be combined, provided they do not exclude each other.

[0010] Figure 1 This illustrates one embodiment of an innovative DART sensor system with a microcontroller and multiple sensors daisy-chained together in a bidirectional wire or row configuration.

[0011] Figure 2 This illustrates another embodiment of an innovative DART sensor system with a microcontroller and multiple sensors daisy-chained together in a bidirectional wire or row configuration.

[0012] Figure 3 This illustrates another embodiment of an innovative DART sensor system with a microcontroller and multiple sensors daisy-chained together in a bidirectional wire or row configuration.

[0013] Figure 4 This illustrates one embodiment of an innovative DART sensor system with a microcontroller and multiple sensors daisy-chained together in a unidirectional loop configuration.

[0014] Figure 5 This illustrates an embodiment of an innovative DART data frame with integrated synchronization pulses.

[0015] Figure 6 A table is shown in which feasible embodiments of instructions can be sent from a microcontroller to a DART sensor.

[0016] Figure 7 This illustration shows an embodiment of a DART sensor and its internal hardware wiring, which enables different states at the first and second I / O pins of the DART sensor.

[0017] Figure 8 A schematic flowchart illustrating one embodiment of the wake-up mode, and

[0018] Figure 9 A schematic state diagram is shown, illustrating different feasible states for the DART sensor. Detailed Implementation

[0019] The embodiments described herein enable multi-sensor systems with two or more sensors that can communicate with each other over a single data line. Asynchronous data protocols can be used for communication. Innovative asynchronous data protocols, for example, can be compatible with existing UART standards. Existing UART interfaces also have a single data line. However, this involves a simple point-to-point connection where the controller is connected to one sensor at a time. In contrast, the concept presented herein connects the controller to multiple sensors and can communicate with these multiple sensors via a single data line. For this purpose, the individual sensors are arranged in a so-called daisy chain and sequentially coupled to the single data line. Therefore, the concept presented herein borrows from UART (Universal Asynchronous Receiver Transmitter) and can also be abbreviated as DART (Daisy Chain Asynchronous Receiver Transmitter).

[0020] The innovative DART concept introduced herein enables multi-sensor networks with different topologies or configurations for joining two or more sensors to a single-wire data line. Here, for example, a ring configuration with preferably unidirectional communication can be involved, where data communication between the controller and the individual sensors occurs in one direction. However, wake-up pulses, etc., can also be sent in the opposite direction. Alternatively, sensors can be joined to the multi-sensor network in a simple line or row topology, where sensors are joined to a single-wire data line in a row, similar to a pearl necklace, and where the single-wire data line has an open end after the last sensor, preferably an open end with a terminating resistor. Here, communication between the controller and the sensors can be bidirectional, that is, along the single-wire data line in both directions. The single-wire data line can have a single data core. The data core can be used not only as a current supply device but also as a transmit and receive line. Because multiple sensors can be joined to a single-wire data line, the DART sensor system introduced herein can also be called a single-wire bus.

[0021] DART in line or strip configuration

[0022] Figure 1 This illustrates a first embodiment of an innovative DART sensor system 100 with asynchronous data transmission. The sensor system 100 has at least two sensors 101, 102, wherein each sensor 101, 102 has a first I / O pin 101. IN 102 IN Second I / O pin 101 OUT 102 OUTIn one conceivable implementation, sensors 101 and 102 may each have exactly two I / O pins 101. IN 102 IN And 101 OUT 102 OUT Therefore, sensors 101 and 102 can be constructed very simply and cost-effectively in terms of hardware.

[0023] The sensor system 100 also includes a control unit 110, for example, in the form of a microcontroller. The microcontroller 110 has a transmit pin 110. Tx and receive pin 110 Rx In one conceivable implementation, the microcontroller 110 may have exactly one transmit pin 110. Tx And exactly one receive pin 110 Rx Therefore, the microcontroller 110 can also be implemented very simply and cost-effectively in terms of hardware.

[0024] The sensor system 100 also includes a single-wire data line 120, through which the microcontroller 110 can communicate with each sensor 101, 102 via an asynchronous data protocol. The single-wire data line 120 is located at the transmit pin 110 of the microcontroller 110. Tx and receive pin 110 Rx Extending between them, each sensor 101, 102 is arranged in a daisy chain 130 and sequentially connected to a single-wire data line 120.

[0025] exist Figure 1 In the embodiment shown, the single-wire data line 120 is at the transmit pin 110 of the microcontroller 110. Tx and receive pin 110 Rx There is a node 140 between them. A single-line data line 120 branches off at the node 140 and extends to a first sensor 101 in a daisy chain 130. The first sensor 101 in the daisy chain 130 is a sensor that is directly connected to the microcontroller 110.

[0026] Single-line data line 120 is located at the first I / O pin 101 of the first sensor 101. IN This connection then connects the first sensor 101 to the previously mentioned node 140. Furthermore, a single-wire data line 120 connects to the second I / O pin 101 of the first sensor 101. OUT The connection is made at the point of contact. The first sensor 101 has internal circuitry to internally relay signals transmitted on the single-wire data line 120. This internal circuitry is described in further detail below.

[0027] The single-wire data line 120 is connected to the second I / O pin 101 of the first sensor 101. OUT And connected to the first I / O pin 102 of the directly adjacent second sensor 102 IN This connects the first sensor 101 to the second sensor 102. Furthermore, a single-wire data line 120 is connected to the second I / O pin 102 of the second sensor 102. OUT .

[0028] If another sensor, such as sensor 103, is present in daisy chain 130, the other sensor is connected to daisy chain 130 in the manner and method described above with its respective first and second I / O pins.

[0029] The last sensor 103 in the daisy chain 130 is its first I / O pin 103. IN Connected to the second-to-last sensor 102 directly adjacent to it. The second I / O pin 103 of the last sensor 103. OUT It can be configured as a non-contact high-impedance floating output terminal.

[0030] In terms of hardware, in the described embodiment, therefore the transmit pin 110 of the microcontroller 110 Tx and receive pin 110 Rx They are connected together, and the first sensor 101 in the daisy chain 130 is connected to the transmit pin 110 of the microcontroller 110. Tx and receive pin 110 Rx Between. The two I / O pins 103 of the last sensor 103 in the daisy chain 130. OUT One of the I / O pins is configured here as a non-contact, high-impedance floating output.

[0031] The line or row topology derived here from the sensor system 100 enables bidirectional data communication between the microcontroller 110 and each of the sensors 101, 102, 103 via a single-line data line 120. The performance of the sensors 101, 102, 103 and the microcontroller 110 in bidirectional data communication is further described in detail below.

[0032] In order to enable bidirectional data communication on the single-wire data line 120, the transmit pin 110 of the microcontroller 110 Tx It can have a push-pull three-state configuration. This will be explained in more detail below.

[0033] If the transmit pin 110 of the microcontroller 110 Tx If the hardware does not have a push-pull tri-state configuration, this can be achieved by modifying the corresponding circuit.

[0034] Figure 2This illustrates one conceivable implementation of an innovative sensor system 100, wherein the transmit pin 110 of the microcontroller 110 Tx It features a push-pull configuration without a tri-state. Here, the microcontroller 110 may have circuitry 150 along with an additional enable pin 151, so that the transmit pin 110... Tx The circuit 150 implements a three-state operation. It can be integrated into the microcontroller 110 or externally inserted into node 140 and transmit pin 110. Tx between.

[0035] Therefore, in Figure 2 In the embodiment depicted, the transmit pin 110 of the microcontroller 110 Tx and receive pin 110 Rx It is connected to the additional enable pin 151. The first sensor 101 in the daisy chain 130 can be connected here to the receive pin 110 of the microcontroller 110. Rx Between and the additional enable pin 151. Because this also involves a wire or row topology, similar to... Figure 1 The embodiment depicted in the diagram shows that the two I / O pins 103 of the last sensor 103 in the daisy chain 130 are... OUT One of the I / O pins can also be configured here as a non-contact high-impedance floating output.

[0036] Therefore, the innovative sensor system 100 is hereby established. Figure 2 The implementation described herein can also enable bidirectional data communication between the microcontroller 110 and the various sensors 101, 102, 103 over a single data line 120.

[0037] Figure 3 Another embodiment of the innovative sensor system 100 is shown, which has a wired or row topology and bidirectional communication over a single-wire data line 120. This embodiment is substantially the same as or similar to the previous embodiments, except that the microcontroller 110 has only a single pin 110. TD The individual pin is designed to be configured as both a transmit pin and a receive pin. Therefore, pin 110... TD This can also be referred to as a combined transmit and receive pin, or a dual-purpose pin. In one design, the microcontroller 110 has exactly one such dual-purpose pin 110. TDF Thus, the microcontroller 110 can be implemented simply and cost-effectively.

[0038] Therefore, in Figure 3The sensor system 100 depicted has at least two sensors 101, 102, and 103, wherein each sensor 101, 102, and 103 has a first I / O pin 101. IN 102 IN 103 IN Second I / O pin 101 OUT 102 OUT 103 OUT .

[0039] The sensor system 100 also includes a microcontroller 110, which has combined transmit and receive pins 110. DP The transmit and receive pins can be internally switched between transmit and receive states.

[0040] The sensor system 100 also includes a single-wire data line 120 through which the microcontroller 110 can communicate with each of the sensors 101, 102, and 103 via an asynchronous data protocol. The sensors 101, 102, and 103 are configured in a daisy-chain 130 and sequentially connected to the single-wire data line 120. The single-wire data line 120 is connected to the combined transmit and receive pins 110 of the microcontroller 110. DP It extends between the various sensors 101, 102, and 103 that are coupled in the daisy chain 130.

[0041] Here, the sensor system 100 is also designed to enable bidirectional data communication between the microcontroller 110 and each of the sensors 101, 102, and 103 via a single-wire data line 120, wherein the transmit and receive pins 110 of the combination of the first sensor 101 and the microcontroller 110 in the daisy chain 130 are configured to facilitate this communication. DP The connection is made between the two I / O pins of the last sensor 103 in the daisy chain 130. OUT One of the I / O pins is configured as a non-contact, high-impedance floating output.

[0042] DART in a ring configuration

[0043] Figure 4An alternative implementation is shown in which the sensor system 100 is designed to enable unidirectional data communication between the microcontroller 110 and the individual sensors 101, 102, 103 via a single-wire data line 120. Unidirectional data communication, within the scope of this disclosure, includes, in particular, the transmission of measurement data, instructions, and configuration data, especially data encoded into one or more bytes. As will be further elaborated later, the sensor system 100 may have an autonomous wake-up mode in which wake-up pulses can be transmitted by the individual sensors in both directions along the single-wire data line 120. These wake-up pulses are therefore not considered unidirectional data communication within the scope of this disclosure.

[0044] As in Figure 4 As can be seen, the sensor system 100 here has a ring configuration, in which the first sensor 101 in the daisy chain 130 is connected in series with the transmit pin 110 of the microcontroller 110 by means of a single-wire data line 120. Tx The connection is made so that the last sensor 103 in the daisy chain 130 is connected in series with the receive pin 110 of the microcontroller 110 via a single-wire data line 120. Rx Connection. As described above with reference to other embodiments, the various sensors 101, 102, 103 within the daisy chain 130 are connected to each other via a single-wire data line 120.

[0045] In all embodiments, the individual sensors 101, 102 disposed within the daisy chain 130 can be directly connected to each other, meaning that there are no additional components in the single-line data line 120 extending between the individual sensors 101, 102.

[0046] Pin configuration of DART microcontroller

[0047] In all implementations, the microcontroller 110 can transmit data, such as commands, via its transmit pin 110. Tx (or dual-purpose pin 110) DP The data is sent to each of the sensors 101, 102, and 103. Sensors 101, 102, and 103 can then send data, such as measurement results, to the microcontroller 110, which can receive the data via its receive pin 110. Rx (or dual-purpose pin 110) DP The data is received at ( ).

[0048] For the purposes described above, the implementations of the innovative sensor system 100 can differ from each other in terms of hardware. Thus, the microcontroller 110 used in a line or bar configuration with bidirectional communication (see...) Figures 1 to 3As mentioned at the beginning, it can have, for example, a transmit pin 110. Tx (or dual-purpose pin 110) DP The transmit pins additionally have a tri-state configuration relative to the push-pull configuration or can be switched to a tri-state state in order to receive data from sensors 101, 102, 103.

[0049] According to this embodiment, the microcontroller 110 can therefore be designed to transmit pin 110 before and during data transmission. Tx Switch to a push-pull configuration so that commands can be sent via a single-wire data line 120 to at least one of the sensors 101, 102, 103 configured in a daisy-chain 130. Furthermore, the microcontroller 110 can be designed to transmit pin 110 before and during receiving data from each of the sensors 101, 102, 103. Tx Switch to the tri-state to release the single-wire data line 120 and sequentially from sensors 101, 102, and 103 via the receive pin 110. Rx Receive data.

[0050] On the contrary, according to Figure 4 The microcontroller 110 used in the ring configuration may have a transmit pin 110 in the hardware. Tx The transmit pin has only a push-pull configuration and optionally does not have a tri-state state. The receive pin 110 of the microcontroller 110... Rx It can be configured as an open-drain input with integrated pull-up resistors in a ring configuration, thereby making it not mandatory to send pin 110 here. Tx The three-state configuration or three-state state.

[0051] In all the embodiments described herein, no external devices, and in particular no resistors, may be provided in the section of the single-wire data line 120 extending between the microcontroller 110 and the first sensor 101 in the daisy-chain 130. Figure 1 and Figure 2 In this context, this is, for example, a section of a single-line data line 120 extending between node 140 and the first sensor 101. Figure 3 and Figure 4 In the middle, this is the transmit pin 110 of the single-wire data line 120. Tx Or transmit-receive pin 110 DP The section extending between the first sensor 101 and the external components. Eliminating additional external components results in a simplified and thus cost-effective construction, and also provides faster data transmission.

[0052] The innovative sensor system 100 may have different sensors 101, 102, and 103. For example, sensors 101, 102, and 103 may be designed to perform magnetic field measurements, particularly 3D measurements in the x, y, and z directions. Alternatively or additionally, sensors 101, 102, and 103 may be designed to measure temperature, velocity, acceleration, humidity, etc. The application areas of sensors 101, 102, and 103 are not limited to specific functions. Sensors 101, 102, and 103 may be equipped with a DART interface for integration into the innovative sensor system 100.

[0053] Sensors 101, 102, and 103 can be used in the following applications, for example:

[0054] • joystick

[0055] • Control components (so-called white goods)

[0056] • Multifunctional button

[0057] • Smart door lock

[0058] • Smart home sensing mechanism

[0059] • Electrometer

[0060] • IoT (Internet of Things) location and proximity sensors

[0061] • Drones and robots

[0062] Sensors 101, 102, and 103 can perform measurements. Measurements can be triggered, for example, by the microcontroller 110 using DART commands. After a measurement is completed, the results are available in the bitmaps of the corresponding sensors 101, 102, and 103. If the sensors are in wake-up mode, sensors 101, 102, and 103 either wait for readings from the microcontroller 110 or, depending on their configuration, directly communicate their measured values ​​to the microcontroller 110. If sensors 101, 102, and 103 are not communicating or measuring, they can remain in power-saving mode.

[0063] DART data frames and DART commands

[0064] To facilitate communication between the microcontroller 110 and sensors 101, 102, and 103, an innovative DART data frame can be used. The DART data frame can be based on, for example, a UART data frame, thus making the innovative DART sensor system 100 compatible with the standardized UART protocol. Therefore, existing UART sensors and UART controllers can be used in the DART sensor system 100 described herein.

[0065] In the DART sensor system 100 described herein, as in UART, the default signal level can be set to high. The following description is based on this assumption. However, it is also conceivable that the default signal level of the innovative DART sensor system 100 is low. In this case, the signal levels and states described subsequently will be exactly the opposite, but this is also covered by the following description.

[0066] Figure 5 An exemplary DART data frame 200 is schematically shown. Data frame 200 has a start bit 210, a stop bit 220, and at least eight data bits 201, 202, ..., 208 interspersed therebetween. The first data bit 201 is the least significant bit (LSB). The last data bit 208 is the most significant bit (MSB). Data frame 200 can be used, for example, to send instructions from microcontroller 110 to one or more sensors 101, 102, 103. Alternatively or additionally, data frame 200 can be used, for example, to send sensor data from one or more sensors 101, 102, 103 to microcontroller 110.

[0067] According to one conceivable implementation, the microcontroller 110 may be designed to send one or more instructions to one or more sensors 101, 102, 103 in a daisy chain 130 via a single-wire data line 120. Here, each instruction may be encoded in a data frame 200.

[0068] Microcontroller 110 can, for example, send measurement commands to sensors 101, 102, and 103. These measurement commands may, for example, involve broadcast measurement commands sent to all sensors 101, 102, and 103 in the daisy-chain 130. Sensors 101, 102, and 103 may or may not implement the measurement commands from microcontroller 110, depending on their configuration. For example, a measurement command for measuring temperature may be implemented only by the temperature sensor, but not by the accelerometer, even if the measurement command has been sent to all sensors 101, 102, and 103 in the daisy-chain 130.

[0069] Sensors 101, 102, and 103 can respond to measurement commands by sending their measurement results, encoded as sensor data in DART data frame 200, to microcontroller 110. If the wake-up mode, described in further detail later, is activated, the sensor data can be read using the same measurement command.

[0070] Simultaneous measurements can be triggered for all connected sensors 101, 102, and 103 using measurement commands, for example. Measurements begin with the rising edge of the stop bit 220 of the measurement command. After measurement, each sensor 101, 102, and 103 sends its released data bytes to the microcontroller 110, starting with the first sensor 101 directly connected to the microcontroller 110. The coordination of the response order of the various sensors 101, 102, and 103 is described in detail below.

[0071] Alternatively or additionally, for measurement commands, microcontroller 110 may send configuration commands to sensors 101, 102, and 103. These configuration commands may, for example, involve broadcast configuration commands sent to all sensors 101, 102, and 103 in the daisy-chain 130. Sensors 101, 102, and 103 may or may not implement the microcontroller 110's configuration commands, depending on the hardware. For example, a configuration command for setting a temperature range may be implemented only by the temperature sensor, but not by the accelerometer, even if the configuration command has been sent to all sensors 101, 102, and 103 in the daisy-chain 130.

[0072] Therefore, configuration commands can be used, for example, to configure all sensors 101, 102, and 103 simultaneously. Following the configuration commands is the desired configuration. For example, a desired magnetic measurement range can be set in a magnetic field sensor, temperature measurement can be activated or deactivated in a temperature sensor, and the energy-saving mode can be turned on or off in sensors equipped with an energy-saving mode.

[0073] The advantage of broadcasting not only the measurement commands described above, but also the configuration commands, is that it eliminates the need for mandatory addressing of the individual sensors 101, 102, 103 within the daisy chain 130. In other words, these sensors can be coupled into the DART sensor system 100 and can communicate directly with other bus participants within the DART sensor system 100. This enhances the plug-and-play capability of the innovative DART sensor system 100.

[0074] Automatic addressing

[0075] Alternatively or additionally, sensors 101, 102, and 103 can also respond individually. For this purpose, microcontroller 110 can be designed to first individually address each sensor 101, 102, and 103 within the daisy chain 130, so that individual measurement commands and / or individual configuration commands can be subsequently sent to the separately addressed sensors. The individualized measurement commands can be signaled to the separately responding sensors to perform measurements independently of the other sensors in the daisy chain 130. The individualized configuration commands can be used to individually configure the separately responding sensors independently of the other sensors in the daisy chain 130.

[0076] In the innovative DART sensor system 100, each sensor can therefore be configured or read individually. Addressing can be performed once before individualized communication. As long as there is no current fault, the addressed sensor remembers its address here.

[0077] Trigger addressing commands sent by microcontroller 110 can be responded to sequentially by sensors 101, 102, and 103 in daisy chain 130. The sensors 101, 102, and 103 respond sequentially, starting with the first sensor 101, which is closest to microcontroller 110. Responses sent by sensors 102 and 103 further down the daisy chain 130 are seen by the sensors in between.

[0078] Each sensor increments its address for each response recognized by other sensors connected downstream in the daisy chain 130. The final state is that the first sensor 101 closest to the microcontroller 110 in the daisy chain 130 has the highest address, which also corresponds to the number of all sensors in the daisy chain 130.

[0079] Therefore, for example, if eight sensors are arranged in a daisy chain 130, the last sensor in the daisy chain furthest from the microcontroller 110 is assigned address 00H. Subsequent sensors along the daisy chain toward the microcontroller 110 in descending order have their addresses corresponding to the number of sensors present, such that the first sensor closest to the microcontroller 110 is thus assigned the highest address in this case, 07H.

[0080] According to this implementation, the microcontroller 110 can therefore be designed to perform an automatic addressing process before individually addressing the sensors 101, 102, 103, during which the sensors 101, 102, 103 in the daisy chain 130 are assigned individual addresses themselves.

[0081] To this end, the microcontroller 110 can be designed to send autoaddressing instructions to sensors 101, 102, and 103 configured in a daisy chain 130 via a single-wire data line 120, wherein each sensor 101, 102, and 103 has an integrated counter whose counter reading represents the individual address of the corresponding sensor 101, 102, and 103, and wherein each sensor 101, 102, and 103 responds to the autoaddressing instructions by independently incrementing its counter reading.

[0082] The automatic addressing instructions can be processed sequentially by sensors 101, 102, and 103 in such a way that the counter readings of each sensor 101, 102, and 103 are incremented by one bit according to the number of sensors following them in the daisy chain 130, so that after a successful automatic addressing process, the first sensor 101 in the daisy chain 130 has the highest counter reading and the last sensor in the daisy chain 130 has the lowest counter reading.

[0083] The addressing order can be reversed, such that the first sensor 101 in the daisy chain 130 has the lowest counter reading and the last sensor in the daisy chain 130 has the highest counter reading.

[0084] The microcontroller 110 can also count all sensor responses to confirm the number of sensors (101, 102, 103) in the daisy chain 130 and determine when the addressing process ends.

[0085] According to this implementation, the microcontroller 110 can therefore be designed, for example, to count the actual number of sensors 101, 102, 103 that address themselves in response to autoaddressing instructions and compare them with the known expected number of sensors in the daisy chain 130. The microcontroller 110 can be designed to send additional instructions and / or receive data only after the autoaddressing process has ended.

[0086] After sensors 101, 102, and 103 have been assigned individual addresses during the automatic addressing process, microcontroller 110 can respond to the corresponding sensor individually via its corresponding address. For example, microcontroller 110 can send individualized measurement commands to the individualized sensors. The individualized measurement commands are sent in DART data frames 200, followed by another DART data frame 200 to obtain the individualized address of the sensor to be responded to. The individually addressed sensor responds using sensor measurement data that it also sends to microcontroller 110 in DART data frames 200.

[0087] Alternatively or additionally, the microcontroller 110 can respond to each sensor individually via its corresponding address after a successful automatic addressing process to configure it. For example, the microcontroller 110 can send individualized configuration instructions to individualized sensors. The individualized configuration instructions are sent in a first DART data frame 200, followed by a second DART data frame 200 containing the individualized address of the sensor to be responded to. This is followed by a third DART data frame 200 containing the desired configuration of the individually addressed sensor.

[0088] Figure 6 A feasible implementation of the action described above is shown, which can be performed by the microcontroller 110 or by sensors 101, 102, 103. Figure 6 The left column of the table depicted lists such actions. The middle column describes the corresponding commands in hexadecimal notation. The right column lists the commands (bins).

[0089] Therefore, for example, the broadcast measurement instruction "Perform Measurement" discussed above is shown in the first line, which is encoded here using Hex code 0x47. This corresponds to the binary sequence (without start bit 0 and stop bit 1) 1110 0010 in DART data frame 200. In response to this, a response in the form of sensor measurement data from all sensors is expected. Because the sensor measurement data in DART data frame 200 can be arbitrary, the sensor measurement data is described in the third column using the value xxxx xxxx between start bit 0 and stop bit 1.

[0090] The second line shows the broadcast configuration command "Configure All Sensors" discussed above, which is encoded here using Hex code 0x77. This corresponds to the binary sequence (without start bit 0 and stop bit 1) 1110 1110 in DART data frame 200. Immediately following, another DART data frame 200 is sent, which acquires the desired configuration. The configuration is illustrated purely exemplarily in the third column using the value bxco nfig between start bit 0 and stop bit 1.

[0091] In the third line, the automatic addressing instruction "Implement Addressing" discussed above is shown, which is encoded here using Hex code 0x44. This corresponds to the binary sequence (without start bit 0 and stop bit 1) 0010 0010 in DART data frame 200. In response to this, the expected response from the sensor is in the form of its own assigned address. The address sent back to microcontroller 110 in DART data frame 200 is illustrated in the third column by the value sens cntX between start bit 0 and stop bit 1. In this example, the address is encoded using 7 bits, which allows up to 128 individual sensors in the DART sensor system 100 to be addressed.

[0092] The fourth line shows the individualized measurement instruction "Individualized Measurement" discussed above. This individualized measurement instruction can be sent after auto-addressing and is encoded here using Hex code 0x74. This corresponds to the binary sequence (without start bit 0 and stop bit 1) 0010 1110 in DART data frame 200. The fifth line shows the individualized configuration instruction "Individualized Reconfiguration" discussed above. This individualized configuration instruction can be sent after auto-addressing and is encoded here using Hex code 0x74. This corresponds to the binary sequence (without start bit 0 and stop bit 1) 0010 1110 in DART data frame 200.

[0093] Because the individualized measurement command "Individualized Measurement" and the individualized configuration command "Individualized Reconfiguration" are structurally similar, they will be described together below.

[0094] Therefore, the first byte 0x74 in data frame 200 initially indicates individualized communication. Then, the second byte... 2 The instruction bytes in the C standard are similarly constructed and contain the following information:

[0095] • If individualized measurements are implemented using sensor response tracking, then the MSB is 1. B (See “senscnt1”), followed by an individualized 7-bit address, where the sensor furthest from the microcontroller 110 has address 00H, or

[0096] • If individualized configuration of the sensor is implemented, then the MSB is 0. B (See “sen scnt0”), followed by an individualized 7-bit address, with the sensor furthest from the microcontroller 110 having address 00H.

[0097] When an individualized measurement command is executed, the individualized addressing sensor is expected to respond in the form of sensor measurement data, which is sent to the microcontroller 110 in a DART data frame 200. The sensor measurement data is illustrated here purely by way of the value xxxx xxxx between the start bit 0 and the stop bit 1.

[0098] When implementing individualized configuration instructions, the microcontroller 110 sends a third DART frame 200 to the individually addressed sensor, which contains the desired configuration. This configuration is illustrated here purely by way of example using the value bxconfig between the start bit 0 and the stop bit 1.

[0099] If any of the sensors 101, 102, or 103 in the daisy chain 130 is in wake-up mode, individualized sensor communication should not be used. Furthermore, automatic addressing must be performed beforehand for individualized measurements / configurations.

[0100] Individualized sensor readouts and configurations are identical for all sensors 101, 102, and 103 in the daisy-chain 130. Following individualized sensor communication, the microcontroller 110 can wait for a time period T before sending the next instruction. time_out_delay .

[0101] Self-synchronization and variable data rate

[0102] Another advantage of the innovative DART sensor system 100 is that it can be self-synchronized. The DART data frame 200 can therefore include at least one synchronization pulse that encodes the current clock rate, bit rate, or baud rate, allowing the receiver of the DART data frame 200 to directly determine the current bit rate or baud rate by reading or decoding the received DART data frame 200 and to adapt to such a rate. Therefore, a high-precision and expensive internal clock generator can be discarded. Instead, a relatively simple and cost-effective clock generator can be used, further simplifying the microcontroller 110 and reducing its price.

[0103] Furthermore, synchronization pulses can be implemented, allowing the microcontroller 110 to theoretically change its current bit rate or baud rate with each individual DART data frame 200. As mentioned earlier, conventional single-wire communication systems are typically based on open-drain circuits with integrated pull-up resistors. However, these open-drain circuits, limited by their architecture, have a relatively slow baud rate of approximately 115.4 kBd at most. In contrast, because the innovative DART sensor system 100 uses a push-pull configuration that can be continuously manipulated (high or low) to provide better power, the bit rate or baud rate can be increased up to 8000 kBd, and even up to 40 MBd in particularly advantageous designs. Therefore, the microcontroller 110 can be designed to transmit data frames 200 with variable baud rates from 100 kBd to 40000 kBd over a single-wire data line 120.

[0104] Figure 5 This section illustrates one of several feasible design options: how at least one synchronization pulse can be integrated into a DART data frame 200. In the non-limiting embodiment shown here, two synchronization pulses 301, 302 are integrated into the DART data frame 200. However, a single synchronization pulse is also conceivable. Synchronization pulses 301, 302 relate to the time interval between two similar edge transitions, which in the example shown here are high-to-low edge transitions. Thus, a single synchronization pulse 301, 302 is characterized by two edge transitions that are fixedly spaced apart from each other in the same direction.

[0105] exist Figure 5 In the example shown where no limiting effect is applied, edge transitions are inserted between the third data bit 203 and the fourth data bit 204, and between the seventh data bit 207 and the eighth data bit 208. Therefore, independent of the actions performed on the DART interface, sensors 101, 102, and 103 always see two fixed-length synchronization pulses 301 and 302 (three falling edges) to achieve the baud rate selected by the microcontroller 110.

[0106] The valid data contained in the DART data frame 200 is set between the corresponding synchronization pulses 301 and 302. The valid data may, for example, relate to instructions of the microcontroller 110, as described above.

[0107] This is also in addition Figure 6 As can be seen, the instructions are shown in the third column of the table. It can be seen here that in each instruction, a high ('1') to low ('0') edge transition occurs between the third and fourth bits and between the seventh and eighth bits, respectively. This relates to the edge transitions described above, which indicate at least one synchronization pulse 301, 302.

[0108] As can be seen, the synchronization pulse (edge ​​transition 1->0) is present at the same location in all instructions. Therefore, different instructions are initially transmitted in the bits in between or in the high-low-time information of synchronization pulses 301 and 302. In other words, the relationship between the duration of the low signal level and the high signal level of synchronization pulses 301 and 302 encodes the corresponding instructions sent by microcontroller 110 to sensors 101, 102, and 103 in the daisy chain 130.

[0109] According to this implementation, the microcontroller 110 can therefore be designed to integrate at least one synchronization pulse 301, 302 in the data frame 200, the synchronization pulse indicating the currently selected bit rate or baud rate. Correspondingly, sensors 101, 102, 103, configured in a daisy-chain 130, are designed to determine the bit rate or baud rate selected by the microcontroller 110 based on the synchronization pulses 301, 302 integrated in the data frame 200, so as to synchronize with the microcontroller 110.

[0110] As mentioned at the beginning, the microcontroller 110 can execute different instructions (see especially) Figure 6 (and the associated description) is sent to sensors 101, 102, and 103 joined in the daisy chain 130. Especially in bidirectional communication, as can be seen, for example, in reference... Figures 1 to 3 As in the discussed embodiments, a response order must be preset, which specifies the order in which each sensor 101, 102, 103 sends its corresponding measurement results (sensor data) to the microcontroller 110, thereby avoiding conflicts on the single-line data line 120.

[0111] DART sensor - hardware circuit

[0112] Another advantage of the innovative concept presented here is that sensors 101, 102, and 103 can negotiate their response order. Therefore, the "intelligence" does not need to be integrated into the microcontroller 110, which benefits from using a simple and cost-effective microcontroller 110. Instead, the "intelligence" is transferred to the sensors 101, 102, and 103 themselves. This is achieved through the specific hardware construction of sensors 101, 102, and 103, which will be referred to below. Figure 7 Brief explanation.

[0113] Figure 7A purely schematic diagram of DART sensor 101 is shown, as it can be used in the DART sensor system 100 described herein. The following description applies in all other respects to all DART sensors 101, 102, and 103. Five different pin configurations are labeled within sensor 101, which can be implemented in hardware. All five variations are described first. However, DART sensors 101, 102, and 103 are not required to have all five configurations.

[0114] First, the first I / O pin 101 of sensor 101 should be kept open. IN It can be used not only as an input pin but also as an output pin, especially in wire or bus topologies with bidirectional communication. Furthermore, only the first I / O pin 101 of sensor 101 is depicted here as a purely exemplary example. IN The description of this, however, applies equally to the second I / O pin 101 of sensor 101 (not depicted here). OUT .

[0115] I / O pin 101 of sensor 101 IN 101 OUT It can have multiple states, but not all states correspond to the corresponding I / O pin 101. IN 101 OUT Required. The required state depends particularly on the application or, but also on, the chosen topology, such as a line or row topology with bidirectional communication. Figures 1 to 3 ) or ring topology ( Figure 4 ).

[0116] First, I / O pin 101 IN 101 OUT The signal can always be received, and the following states are possible under other circumstances:

[0117] 1. Pull-Up: I / O pin 101 IN Pulled high via a resistor. The standard Sens- level is high and can only be pulled low to ground via an external connection. (Received while transmitting a signal)

[0118] 2. Push-Pull-High: I / O pin 101 IN It is at a high level and can also pull connected components to a high level. (Send)

[0119] 3. Tri-State: I / O pin 101 IN It is "floating," has high impedance, and reaches the level of the connected component. (Receiver)

[0120] 4. Push-Pull-Low: I / O pin 101 IN It is at a low level and can also pull the connected components low. (Send)

[0121] 5. Pull-Down: I / O pin 101 IN Pulled low via a resistor. The standard Sens- level is low and can only be pulled high to VCC via an external connection. (Received during transmit signal)

[0122] After discussing the hardware design of sensors 101, 102, and 103, the following describes different applications in which sensors 101, 102, and 103 can be implemented independently. This begins with the application mentioned above, which involves the independent coordination of the response sequence for transmitting measurement results (sensor data) to the microcontroller 110. This is not only used in line or row topologies with bidirectional communication, but also in… Figures 1 to 3 As shown in the diagram, and used in ring configurations with unidirectional communication, as it is in Figure 4 As depicted in the text.

[0123] Coordination of response sequence of DART sensors in line or bar configuration

[0124] First, let's discuss the basis... Figures 1 to 3 Coordination of the response order in a line or row topology. The following discussion will focus on... Figure 4 Coordination of response order in a ring topology.

[0125] According to one embodiment, sensors 101, 102, 103 configured in a line or row are designed to transmit their measurement data to microcontroller 110 in ascending response order, starting with sensor 101 closest to microcontroller 110 in terms of connection order in daisy chain 130, and ending with sensor 103 furthest from microcontroller 110.

[0126] To coordinate the response sequence, sensors 101, 102, and 103 perform the following steps after receiving an instruction from microcontroller 110 requiring a sensor response (e.g., a measurement result):

[0127] In obtaining measurement instructions from microcontroller 110 (see, for example) Figure 6 After (0x47H "Perform Measurement"), sensors 101, 102, and 102 connect their first I / O pin 101. IN 102 IN 103 IN (See) Figures 1 to 3 Place it in state 1 (pull-up) and set its second I / O pin 101. OUT 102OUT 103 OUT Place it in state 4 (push-pull low) as described above.

[0128] As long as the sensor (e.g., sensor 102) is located at position X in the daisy chain 130, on its first I / O pin 102 IN A high level is detected at (e.g., via the receive pin 110 of the microcontroller 110). Rx Initialization (either by pulling up the sensor or by initialization via the previous sensor 101) means that sensor 102 at position X knows it is its turn to transmit its sensor data. To transmit sensor data, the sensor connects its first I / O pin 102. IN It transitions between states 2 (push-pull high) and 4 (push-pull low), while its second I / O pin 102 OUT Remain in state 4 (push-pull low).

[0129] Therefore, sensors 101, 102, and 103 are designed to activate their first I / O pin 101 after receiving a measurement command. IN 102 IN 103 IN Switch to pull-up state and set its second I / O pin 101 OUT 102 OUT 103 OUT Switching to push-pull low state, wherein if sensor 102 is set at position X in daisy chain 130 at its first I / O pin 102 IN The sensor only sends its measurement data toward the microcontroller 110 when it receives a high signal level, wherein the high signal level comes either from the sensor 101 directly adjacent to the microcontroller 110 or from the microcontroller 110 itself. The sensor 102 located at position X is also designed to transmit its measurement data via its first I / O pin 102. IN It switches between push-pull high and push-pull low states (that is, it switches back and forth), and its second I / O pin 102 OUT Keep it in the push-pull low state.

[0130] If sensor 102 at position X has finished its data output, it will then set its second I / O pin 102. OUT Set it to state 1 (pull-up) and set its first I / O pin 102 IN Also placed in state 1 (pull-up). The other sensors 103 located further down in the single-line data line 130 know that it is now their turn to communicate and send their sensor data (measurement results).

[0131] Therefore, the sensor 102 located at position X can be designed to not only send its first I / O pin 102 after successfully transmitting measurement data. IN Furthermore, its second I / O pin 102 OUT Switch to pull-up state so that a signal can be transmitted to the sensor 103 directly adjacent to the microcontroller 110 by means of a high signal level: now it is the adjacent sensor 103's turn to send its measurement results in the form of sensor data encoded in DART data frame 200.

[0132] The sensor 102, positioned at location X, can now transmit sensor data obtained from the adjacent sensor 103 toward the microcontroller 110. Here, the sensor 102 positioned at location X can first transmit this data via its second I / O pin 102. OUT The sensor detects a low pulse from the adjacent sensor 103, even when its second I / O pin 102 is activated. OUT Remain in state 1 (pull up).

[0133] The low pulse containing sensor data from the adjacent sensor 103 is sent or forwarded to the microcontroller 110 by means of: the first I / O pin 102 of the sensor 102 located at position X. IN The sensor is placed in state 4 (push-pull low) during the duration of the received low pulse. After the low pulse ends, the first I / O pin 102 of sensor 102 at position X is activated. IN The state automatically changes back to state 1 (pull-up) because the signal level on the single-line data line 120 is high according to the standard.

[0134] In other words, the sensor data of the adjacent sensor 103 is transmitted by the sensor 102 located at position X via its second I / O pin 102. OUT The device receives and internally forwards the data to its first I / O pin 102. IN This is so that sensor data from the adjacent sensor 103 can be transferred to the microcontroller 110. Therefore, on the second I / O pin 102... OUT Sensor data received at the first I / O pin 102 IN Mapping at the location.

[0135] Therefore, if the sensor 102 located at position X has its second I / O pin 102 OUT If a high signal level is received from a neighboring sensor 103 during the period of receiving sensor data from the neighboring sensor 103, then that sensor must also have a high signal level on its first I / O pin 102. INThe high signal level is output at the location. Conversely, if sensor 102 located at position X (during the period of receiving sensor data from adjacent sensor 103) outputs the high signal level at its second I / O pin 102. OUT If a low signal level is received from the adjacent sensor 103, then that sensor must also respond on its first I / O pin 102. IN It outputs its low signal level.

[0136] Therefore, the sensor 102 located at position X can be designed to transfer sensor data (e.g., measurement results or measurement data) from the adjacent sensor 103 along a daisy chain 130 toward the microcontroller 110, in such a way that the sensor will transmit the data to its second I / O pin 102 during the reception of measurement data. OUT The signal level received from the adjacent sensor 103 is located on its first I / O pin 102. IN Mapping at the location.

[0137] Therefore, the sensor 102 located at position X can be designed to switch its first I / O pin 102 to a low signal level for a duration during the reception of sensor data from the adjacent sensor 103. IN Switch to push-pull low state (state 4), and for the duration of the received high signal level, set its first I / O pin 102... IN Switch to push-pull high (state 2) or switch back to pull-up state (state 1).

[0138] The microcontroller 110 knows when it will stop receiving additional sensor data and can then send new instructions. Therefore, the microcontroller 110 can be designed to wait to fully acquire the measurement data of all sensors 101, 102, and 103 set up in the daisy chain 130 before sending additional instructions to the sensors 101, 102, and 103.

[0139] As mentioned at the beginning, the sensor 102 located at position X can be designed to internally process measurement data obtained from the adjacent sensor 103 on its first and second I / O pins 102. IN 102 OUT The data is transmitted between the sensors so that measurement data obtained from the adjacent sensor 103 can be forwarded to the microcontroller 110.

[0140] Instead of digital data transfer originating from information pulses or actual data transmission, internal signal transfer can also be achieved using buffers or analog signal paths. Therefore, the sensor 102 positioned at location X can, for example, have an integrated digital buffer circuit to convert the measurement data digitally at pin 102. IN 102 OUTThe data is transferred between the sensor and the input pin. Alternatively or additionally, the sensor 102 located at position X may have an integrated impedance transformer to transmit the measurement data in analog form to pin 102. IN 102 OUT Transferred between them.

[0141] In summary, the innovative DART sensors 101, 102, and 103 can therefore be designed to utilize their first and second I / O pins 101 IN 101 OUT 102 IN 102 OUT 103 IN 103 OUT To enable independent coordination of the response order in a line or row configuration, at least the following states must be switched to:

[0142] • First I / O pin 101 IN 102 IN 103 IN Statuses 1, 2, and 4

[0143] • Second I / O pin 101 OUT 102 OUT 103 OUT Statuses 1, 2, and 4

[0144] Coordination of response sequence of DART sensors in ring configuration

[0145] The embodiments described above relate to, as in Figures 1 to 3 The coordination of the response sequence of sensors 101, 102, and 103 in the line or row configuration depicted below. The following should discuss how... Figure 4 The diagram illustrates the concept of coordinating the response sequence of sensors 101, 102, and 103 in a ring configuration. The ring configuration can include unidirectional communication. However, bidirectional communication, at least between sensors 101, 102, and 103, is also conceivable.

[0146] According to one embodiment, sensors 101, 102, and 103, arranged in a ring configuration, are designed to transmit their measurement data in a descending response order, i.e., to the receiver pin 110 closest to the microcontroller 110. Rx Positioning sensors 101 (in the daisy-chain 130 connection order) start from the nearest transmit pin 110 of the microcontroller 110. Tx The positioning sensor 103 transmits the data to the microcontroller 110.

[0147] To coordinate the response order, it is set to be based on Figure 4After receiving an instruction from the microcontroller 110 requiring a sensor response (e.g., a measurement result), the ring-shaped sensors 101, 102, and 103 perform the following steps:

[0148] In obtaining measurement instructions from microcontroller 110 (see, for example) Figure 6 After (0x47H "Perform Measurement"), sensors 101, 102, and 102 connect their first I / O pin 101. IN 102 IN 103 IN (See) Figure 4 Place it in state 5 (pull down) and set its second I / O pin 101. OUT 102 OUT 103 OUT In state 1 (pull-up) above, the pull-up resistor can be several times larger than the pull-down resistor.

[0149] Therefore, the sensors 101, 102, and 103 configured in a daisy chain 130 can be designed to connect their first I / O pin 101 after receiving a measurement command. IN 102 IN 103 IN Switch to pull-down mode and set its second I / O pin 101 OUT 102 OUT 103 OUT Switch to pull-up mode, where the pull-up resistor should be at least as large as the pull-down resistor so that the value generated in the potentiometer is pulled to a defined signal level.

[0150] If the closest to the transmit pin 110 of the microcontroller 110 Tx The positioning sensor 101 is located on its first I / O pin 101. IN If a high signal level is detected at a certain location, the sensor 101 knows that it is the last in the response sequence and therefore activates its first I / O pin 101. IN Switch to state 3 (tri-state).

[0151] As long as the sensor is located at position X, for example, sensor 102 on its second I / O pin 102 OUT If a high signal level is detected at position X, the sensor 102 located at position X knows that it is now its turn to transmit its measurement data. Therefore, the sensor 102 located at position X can activate its second I / O pin 102. OUT It switches between states 2 (push-pull high) and 4 (push-pull low) (that is, it switches back and forth), and its first I / O pin 102 IN Stay in state 5 (dropdown).

[0152] If sensor 102 at position X has finished its data output, it will set its first I / O pin 102. IN Set it to state 3 (tri-state) and set its second I / O pin 102 OUT Set to state 2 (push-pull high). Then, the sensor with the lower address knows that it is now its turn to communicate and send its data.

[0153] Therefore, the sensor 102 located at position X can be designed to connect its first I / O pin 102 after successfully transmitting its measurement data. IN Switch to the tri-state so that a signal can be sent to the transmit pin 110 of the microcontroller 110 by means of a high signal level. Tx Immediately adjacent sensor 101 transmission: The sensor is the next in the response sequence to transmit its measurement data. The adjacent sensor 101 can also be designed to transmit its measurement data in the form of sensor data encoded in DART data frame 200 in response to a received high signal level.

[0154] Sensor 102, positioned at location X, can now direct sensor data acquired from the adjacent sensor 101 toward the receive pin 110 of the microcontroller 110. Rx Forwarding. Here, the sensor 102 located at position X can first be transferred via its first I / O pin 102. IN The sensor detects a low pulse from the adjacent sensor 101, even when its first I / O pin 102 is activated. IN Remain in state 3 (three-state).

[0155] From (near the receive pin 110 of the microcontroller 110) Rx The low pulse of sensor 101 on the left side (position X) is emitted by sensor 102 located at position X on its first I / O pin 102. IN Location identification. A low pulse containing sensor data from other sensors 101 is sent to the receive pin 110 of the microcontroller 110. Rx The method is as follows: the sensor 102 located at position X connects its second I / O pin 102. OUT The received low pulse is in state 4 (push-pull low). After the low pulse ends, the second I / O pin 102... OUT The state changes to 2 (push-pull high).

[0156] Therefore, a low pulse containing sensor data from adjacent sensor 101 is sent or relayed to the receive pin 110 of microcontroller 110. Rx The method is as follows: the second I / O pin 102 of the sensor 102 located at position X is... OUTThe sensor is placed in state 4 (push-pull low) during the duration of the received low pulse. After the low pulse ends, the second I / O pin 102 of the sensor 102 at position X is activated. OUT The state automatically changes back to state 2 (push-pull high) because the signal level on the single-line data line 120 is at a high level in accordance with the standard.

[0157] In other words, the sensor data of the adjacent sensor 101 is transmitted by the sensor 102 located at position X via its first I / O pin 102. IN It receives and internally forwards the data to its second I / O pin 102. OUT This is so that sensor data from the adjacent sensor 101 can be transferred to the microcontroller 110. Therefore, on the first I / O pin 102... IN Sensor data received at the second I / O pin 102 OUT Mapping at the location.

[0158] Therefore, if the sensor 102 located at position X has its first I / O pin 102 IN If a high signal level is received from a neighboring sensor 101 during the period of receiving sensor data from the neighboring sensor 101, then that sensor must also transmit the high signal level to its second I / O pin 102. OUT The output is located at X. Conversely, if sensor 102 located at position X (during the period of receiving sensor data from adjacent sensor 101) is on its first I / O pin 102... IN If a sensor receives a low signal level from an adjacent sensor 101, then that sensor must also transmit the low signal level to its second I / O pin 102. OUT Output at the specified location.

[0159] Therefore, the sensor 102 located at position X can be designed to transfer sensor data (e.g., measurement results or measurement data) from the adjacent sensor 101 along a daisy chain 130 toward the microcontroller 110, in such a way that the sensor will transmit the data at its first I / O pin 102 during the reception of measurement data. IN The signal level received from the adjacent sensor 101 is located on its second I / O pin 102. OUT Mapping at the location.

[0160] Therefore, the sensor 102 located at position X can be designed to switch its second I / O pin 102 to a low signal level for a duration during the reception of sensor data from the adjacent sensor 101. OUT Switch to push-pull low state (state 4), and for the duration of the received high signal level, set its second I / O pin 102. OUTSwitch to push-pull high (state 2) or pull-up state (state 1).

[0161] The microcontroller 110 knows when it will stop receiving additional sensor data and can then send new instructions. Therefore, the microcontroller 110 can be designed to wait to fully acquire the measurement data of all sensors 101, 102, and 103 set up in the daisy chain 130 before sending additional instructions to the sensors 101, 102, and 103.

[0162] As mentioned at the beginning, the sensor 102 located at position X can be designed to internally store the measurement data obtained from the adjacent sensor 101 on its first and second I / O pins 102. IN 102 OUT The data is transmitted between the sensors so that measurement data obtained from the adjacent sensor 101 can be forwarded to the microcontroller 110.

[0163] Instead of digital data transfer originating from information pulses or actual data transmission, internal signal transfer can also be achieved using buffers or analog signal paths. Therefore, the sensor 102 positioned at location X can, for example, have an integrated digital buffer circuit to convert the measurement data digitally at pin 102. IN 102 OUT The data is transferred between the sensor and the input pin. Alternatively or additionally, the sensor 102 located at position X may have an integrated impedance transformer to transmit the measurement data in analog form to pin 102. IN 102 OUT Transferred between them.

[0164] In summary, the innovative DART sensors 101, 102, and 103 can be designed to use their first and second I / O pins 101 IN 101 OUT 102 IN 102 OUT 103 IN 103 OUT To enable independent coordination of the response order within the ring configuration, at least the following states must be switched to:

[0165] • First I / O pin 101 IN 102 IN 103 IN Status 3 and 5

[0166] • Second I / O pin 101 OUT 102 OUT 103 OUT Statuses 1, 2, and 4

[0167] In the embodiments described above, the microcontroller 110 has sent measurement commands to sensors 101, 102, and 103, and then sensors 101, 102, and 103 have transmitted their corresponding sensor data (measurement results) to the microcontroller 110. That is, the measurement has been triggered by the microcontroller 110 using measurement commands.

[0168] Wake-up mode

[0169] In another design of the innovative DART sensor system 100, measurements can be taken if the wake-up function is activated, but can also be triggered by the sensors 101, 102, and 103 themselves. That is, the DART sensors 101, 102, and 103 can be configured in a wake-up mode, which will be described in detail below.

[0170] For example, one or more sensors 101, 102, 103 may operate in wake-up mode. In wake-up mode, sensors 101, 102, 103 perform routine measurements without control or explicit measurement instructions from the microcontroller 110. If a predefined measurement value is exceeded, sensors 101, 102, 103 independently transmit a wake-up signal to the microcontroller 110.

[0171] Sensors 101, 102, and 103 can be periodically woken up, with the cycle (e.g., every ~0.8s) being individually configurable. Configuration can be performed, for example, by means of the aforementioned broadcast configuration instructions or by means of individually addressed configuration instructions. Alternatively or additionally, a threshold measurement value can be determined, which can also be freely configured. The threshold measurement value can be set for one or more sensors 101, 102, and 103 and set, for example, by means of the aforementioned broadcast configuration instructions or by means of individually addressed configuration instructions. Instead of the threshold measurement value, a threshold measurement range can also be specified.

[0172] If the signal measured by sensors 101, 102, and 103 is outside the configured threshold measurement value or outside the configured threshold measurement range, the corresponding sensors 101, 102, and 103 can send a wake-up signal to the microcontroller 110. The corresponding sensor and the remaining sensors remain awake, store their last measurement results, and wait to be read by the microcontroller 110.

[0173] Sensors 101, 102, and 103 can then be configured in an autonomous wake-up mode, in which they can cyclically and independently wake up from a sleep mode. Sensors 101, 102, and 103 configured in wake-up mode can be designed to wake up from sleep at a predetermined repetition rate without explicit measurement instructions from the microcontroller 110, so as to independently perform measurements, and then return to sleep after a successful measurement.

[0174] If the measured value obtained by sensors 101, 102, and 103 in wake-up mode is higher than a predetermined threshold, then sensors 101, 102, and 103 in wake-up mode can store their last measured value and send wake-up pulses along daisy chain 130 in at least one, preferably in two directions, such that the wake-up pulses are sent to other sensors and / or microcontroller 110. Other sensors 101, 102, and 103 can also store their current measured value at the stated time. Sensors 101, 102, and 103 can then remain awake until they receive a read command or configuration command from microcontroller 110.

[0175] To end the wake-up mode, sensors 101, 102, and 103 must be reconfigured, which can be done, for example, by means of configuration instructions sent by microcontroller 110. Alternatively or additionally, in contrast to the wake-up events triggered by sensors exceeding / below thresholds as described above, microcontroller 110 may also trigger wake-up events itself to, for example, forcibly end the wake-up mode.

[0176] Wake-up modes can be activated, for example, by selecting a wake-up frequency. Wake-up modes can be activated after a specific waiting time T. wake_up_delay Then it begins after the final stop bit (rising edge) sent by the microcontroller. Then, in wake-up mode, sensors 101, 102, and 103 can independently perform measurements at a selected wake-up frequency.

[0177] A wake-up event is triggered if at least one of the measured values ​​falls outside a configurable wake-up threshold. The single-line data line 120 is used for this purpose by the corresponding sensors 101, 102, and 103 for a predetermined duration T. wake_up_pulse The signal is pulled low and the corresponding sensors 101, 102, and 103 stop measuring and wait for readings from the microcontroller 110.

[0178] If sensors 101, 102, and 103 determine a low signal level on single-line data line 120 (e.g., triggered by other sensors), the sensors also stop their measurements and wait for their last measured value to be read by microcontroller 110.

[0179] The reading by the microcontroller 110 should preferably occur as early as a predefined waiting time T. wake_up_read Then proceed. For the wake-up mode to begin measurement again, two conditions must be met:

[0180] • The corresponding sensors 101, 102, and 103 have responded to the read command triggered by the microcontroller 110, and

[0181] • Single-line data line 120 for T wake_up_delay The duration remains at a high level.

[0182] Conversely, if sensors 101, 102, and 103 are in wake-up mode and no wake-up event has been triggered, a read command should not be executed.

[0183] Figure 8 A schematic flowchart illustrating a non-limiting example of a configurable wake-up mode is shown. Box 801 marks the beginning of the process sequence. The sensor is configured in wake-up mode in box 802. After a waiting time T... wake_up_delay (Transition 803) After that, sensors 101, 102, and 103 are in a wake-up mode (block 804), in which sensors 101, 102, and 103 autonomously wake up from sleep at a freely configurable regular interval and perform one or more measurements.

[0184] If one of the sensors 101, 102, and 103 measures below or above a threshold (depending on the configuration), a wake-up pulse is sent by said sensor 101, 102, or 103 (see transition 805). In other cases, sensors 101, 102, and 103 transition back to sleep mode.

[0185] Once a wake-up pulse is sent by one of the sensors 101, 102, 103, the microcontroller 110 may eventually send an interrupt pulse to temporarily halt the wake-up mode, and all sensors 101, 102, 103 may store their current measurement values ​​at the time (when a wake-up pulse or an interrupt pulse is sent) (see block 806).

[0186] After waiting time T wake_up_read(Transition 807) After this, microcontroller 110 can send instructions (block 808) for reading stored measurement data to sensors 101, 102, and 103, which then send their measurement data back to microcontroller 101, 102, and 103. Alternatively, microcontroller 110 can send configuration instructions to sensors 101, 102, and 103 to reconfigure the sensors. It is also conceivable that microcontroller 110 sends two instructions—one for reading sensors 101, 102, and 103 and one for configuring sensors 101, 102, and 103—to sensors 101, 102, and 103 sequentially (in no particular order). With the configuration instructions (transition 810), sensors 101, 102, and 103 are reconfigured. For example, this can end the wake-up mode.

[0187] Conversely, in the case of instructions for reading measurement data (transformation 809), sensors 101, 102, and 103 transmit their measurement data and then wait for a subsequent time T. wake_up_delay It then transitions to a wake-up mode, in which the sensor transitions to sleep and is then woken up from its sleep phase at configurable, regular intervals (see transition 803 and block 804).

[0188] As already mentioned, the intelligence of the DART sensor system 100 can be integrated into the hardware of sensors 101, 102, and 103. Subsequently, when each sensor is in wake-up mode, the corresponding hardware states of each sensor 101, 102, and 103 are described. Refer here to states 1 through 5, as previously mentioned. Figure 7 As described.

[0189] Wake-up mode in line or bar configuration

[0190] First, describe the use of according to Figures 1 to 3 The wake-up modes of sensors 101, 102, and 103 in the line or row configuration. Subsequently, a description is provided for... Figure 4 The wake-up modes of sensors 101, 102, and 103 in the ring configuration.

[0191] In an online or offline configuration, the microcontroller 110 can first send its data via pin 110. Tx Switch to the tri-state to receive measurement data or wake-up pulses from sensors 101, 102, and 103.

[0192] Sensors 101, 102, and 103 in wake-up mode can be designed such that, after being placed in wake-up mode, their respective first I / O pins 101... IN 102 IN 103IN Second I / O pin 101 OUT 102 OUT 103 OUT First, switch to the pull-up state (state 1).

[0193] The following description uses sensor 102 as an example to illustrate the behavior of sensors 101, 102, and 103 in wake-up mode. However, it is obvious that the following description applies to all sensors 101, 102, and 103 in wake-up mode.

[0194] In sensor 102 in wake-up mode, two scenarios can be envisioned. The first option proposes that sensor 102, on its first or second I / O pin 102... IN 102 OUT A low pulse was detected at the location. That is, the wake-up pulse was sent to sensor 102 by one of the adjacent sensors 101 or 103. This wake-up pulse depends on which adjacent sensor 101 or 103 it originated from, i.e., which I / O pin 102 it was sent to. IN 102 OUT At this point, sensor 102 receives a wake-up pulse and forwards the signal to the opposite side or to these two I / O pins 102. IN 102 OUT The other I / O pins are configured as follows: The corresponding other I / O pin 102 IN 102 OUT The duration of the identified low pulse is switched to a push-pull low state (state 4). Thus, the low pulse is transferred from one side to the other. Here, the sensor 102, in wake-up mode, can transfer the wake-up pulse in both directions. The sensor 102 then remains awake and waits for a read command from the microcontroller 110, responding to the read command with its current measurement value.

[0195] According to this implementation, the sensor 102 in wake-up mode can therefore be designed with its first or second I / O pin 102... IN 102 OUT The sensor detects low signal levels from directly adjacent sensors 101 and 103, where the low signal level marks a wake-up pulse.

[0196] The sensor 102 in wake-up mode can be designed with its first or second I / O pin 102 IN 102 OUT After detecting the wake-up pulse, the corresponding other I / O pins 102 will be activated. IN 102 OUTDuring the duration of receiving the wake-up pulse, switch to push-pull low state (state 4) so ​​that the wake-up pulses of adjacent sensors 101 and 103 are transmitted in the opposite direction.

[0197] After the wake-up pulse is transmitted, the sensor 102 in wake-up mode can remain awake and either wait for a read instruction from the microcontroller 110 to transmit its own current measurement data in response, or wait for a configuration instruction from the microcontroller 110 to change its own configuration in response.

[0198] A second conceivable option proposes that the sensor 102, in wake-up mode, measures a value exceeding a predefined wake-up threshold and then sends a wake-up pulse. In this case, the sensor 102 not only places its first I / O pin 102 in a push-pull low state (state 4), but also... IN Furthermore, it also places the second I / O pin 102 in the push-pull low state (state 4). OUT The signal is pulled low to send a wake-up pulse. Here, sensor 102, in wake-up mode, can send the wake-up pulse in both directions. Sensor 102 then remains awake and waits for a read command from microcontroller 110.

[0199] In this embodiment, the sensor 102 in wake-up mode can therefore be designed such that if the measured value obtained by the sensor 102 in wake-up mode during measurement is higher than a predetermined threshold, it stores its last obtained measured value and sends its own wake-up pulse along the daisy chain 130, and remains awake until it receives a read instruction or configuration instruction from the microcontroller 110.

[0200] The sensor 102 in wake-up mode can also be designed to connect its first and second I / O pins 102 in order to send a wake-up pulse. IN 102 OUT Switch to push-pull low state (state 4). Alternatively or additionally, sensor 102 in wake-up mode can be designed to switch its first and second I / O pins 102 to a push-pull low state after receiving a read command or configuration command. IN 102 OUT It then switches back to the pull-up state (state 1).

[0201] Another alternative is that the microcontroller 110 sends a wake-up pulse to one or more of the sensors 101, 102, and 103 that are in wake-up mode, in order to wake the sensors 101, 102, and 103 from sleep mode. The behavior of sensors 101, 102, and 103 in wake-up mode is also described below using sensor 102 as an example. However, it is obvious that the following description applies to all sensors 101, 102, and 103 in wake-up mode.

[0202] According to this embodiment, the sensor 102 in wake-up mode can be designed with its first I / O pin 102 IN The sensor detects a low signal level from the microcontroller 110, which will be used to signal the wake-up pulse of the sensor 102 in wake-up mode.

[0203] Sensor 102 in wake-up mode can relay a wake-up pulse from microcontroller 110 to subsequent sensors 103 in the daisy chain 130. For this purpose, sensor 102 in wake-up mode can be designed with its first I / O pin 102... IN After detecting the wake-up pulse, it sets its second I / O pin 102. OUT During the duration of receiving the wake-up pulse, switch to push-pull low state (state 4) so ​​that the wake-up pulse from the direction of the microcontroller 110 is transferred in the opposite direction.

[0204] After detecting a wake-up pulse, the sensor 102 in wake-up mode can remain awake to wait for a read command from the microcontroller 110 to transmit its current measurement data, or to wait for a configuration command from the microcontroller 110 to change its configuration.

[0205] As mentioned at the beginning, sensor 102 in wake-up mode can internally transmit wake-up pulses (from microcontroller 110 or other sensors 101, 103) on its two I / O pins 102. IN 102 OUT The data is transferred between the information pulse and the actual data transmission. Instead of digital data transfer originating from the information pulse or actual data transmission, the internal transfer of the wake-up pulse can also be achieved using a buffer or analog signal path. Therefore, the sensor 102 in wake-up mode can, for example, have an integrated digital buffer circuit to digitally transmit the wake-up pulse to pin 102. IN 102 OUT The signal is transmitted between the sensor and the receiver. Alternatively or additionally, the sensor 102 in wake-up mode may have an integrated impedance transformer to transmit the wake-up pulse in analog form at pin 102. IN 102 OUTTransferred between them.

[0206] In short, therefore, it can be based on Figures 1 to 3 The innovative DART sensors 101, 102, and 103, configured in a line or bar configuration, are placed in an autonomous wake-up mode, wherein their first and second I / O pins 101 IN 101 OUT 102 IN 102 OUT 103 IN 103 OUT It can occupy at least the following states:

[0207] • First I / O pin 101 IN 102 IN 103 IN : States 1 and 4

[0208] • Second I / O pin 101 OUT 102 OUT 103 OUT : States 1 and 4

[0209] Wake-up mode in ring configuration

[0210] In describing the use of according to Figures 1 to 3 After discussing the wake-up modes of sensors 101, 102, and 103 in the line or row configuration, the following discussion focuses on the use of... Figure 4 The wake-up modes of sensors 101, 102, and 103 in the ring configuration.

[0211] In a ring configuration, microcontroller 110 can first send its signal pin 110. Tx Switch to open-drain state to receive measurement data or wake-up pulses from sensors 101, 102, and 103.

[0212] Sensors 101, 102, and 103 in wake-up mode can be designed such that, after being placed in wake-up mode, their respective first I / O pins 101... IN 102 IN 103 IN Second I / O pin 101 OUT 102 OUT 103 OUT First, switch to the pull-up state (state 1).

[0213] The following description uses sensor 102 as an example to illustrate the behavior of sensors 101, 102, and 103 in wake-up mode. However, it is obvious that the following description applies to all sensors 101, 102, and 103 in wake-up mode.

[0214] In sensor 102 in wake-up mode, two scenarios can be envisioned. The first option proposes that sensor 102, on its first or second I / O pin 102... IN 102 OUT A low pulse was detected at the location. That is, the wake-up pulse is sent to sensor 102 by one of the adjacent sensors 101 or 103. This wake-up pulse depends on which adjacent sensor 101 or 103 it originates from, i.e., on which I / O pin 102. IN 102 OUT At this point, sensor 102 receives a wake-up pulse and forwards the signal to the opposite side or two I / O pins 102. IN 102 OUT Each of the other I / O pins.

[0215] For example, if sensor 102 is in wake-up mode, its first I / O pin 102 IN The sensor receives a wake-up pulse and forwards the wake-up pulse to its second I / O pin 102. OUT Then the sensor will set its second I / O pin 102 OUT The duration of the identified low pulse switches to a push-pull low state (state 4). Thus, the low pulse originates from one side, that is, from the first I / O pin 102. IN The signal is transferred to the other side, that is, to the second I / O pin 102. OUT The sensor 102 then remains alert and waits for a read command from the microcontroller 110, to which the sensor 102 responds with the current measurement value.

[0216] According to this implementation, the sensor 102 in wake-up mode can therefore be designed with its first I / O pin 102... IN The transmitter pin 110 is used to detect signals from the transmitter pin 110 of the microcontroller 110. Tx The low signal level of the directly adjacent sensor 101, where the low signal level marks the wake-up pulse.

[0217] The sensor 102 in wake-up mode can be designed with its first I / O pin 102 IN After detecting a low signal level, it sets its second I / O pin 102. OUT The duration of the wake-up pulse is switched to a push-pull low state (state 4) so ​​that the received wake-up pulse is directed along daisy chain 130 toward the receive pin 110 of microcontroller 110. Rx The wake-up pulse is then transmitted to the sensor 103 connected in the rear of the daisy chain 130.

[0218] After receiving and transmitting a wake-up pulse, the sensor 102 in wake-up mode can remain awake and either wait for a read instruction from the microcontroller 110 to transmit its own current measurement data in response, or wait for a configuration instruction from the microcontroller 110 to change its own configuration in response.

[0219] After receiving a read instruction or configuration instruction from the microcontroller 110, the sensor 102, which is in wake-up mode, can connect its first and second I / O pins 102. IN 102 OUT It then switches back to the pull-up state (state 1).

[0220] Conversely, if sensor 102 is in wake-up mode, its second I / O pin 102 OUT The sensor receives a wake-up pulse and forwards the wake-up pulse to its first I / O pin 102. IN Then the sensor will connect its first I / O pin 102 IN The duration of the identified low pulse is switched to the pull-down state (state 5). Thus, the low pulse originates from one side, that is, from the second I / O pin 102. OUT Transferred to the other side, that is, the first I / O pin 102 IN The sensor 102 then remains alert and waits for a read command from the microcontroller 110, to which the sensor 102 responds with the current measurement value.

[0221] According to this implementation, the sensor 102 in wake-up mode can therefore be designed with its second I / O pin 102... OUT The detector detects the signal from the receive pin 110 of the microcontroller 110. Rx The low signal level of the directly adjacent sensor 103, where the low signal level marks the wake-up pulse.

[0222] The sensor 102 in wake-up mode can be designed with its second I / O pin 102 OUT After detecting a low signal level, it sets its first I / O pin 102 IN The duration of the received wake-up pulse is switched to a pull-down state (state 5) so that the received wake-up pulse is directed along daisy chain 130 toward the transmit pin 110 of microcontroller 110. Tx The wake-up pulse is then transmitted to the sensor 101 connected in front in the daisy chain 130.

[0223] After receiving and transmitting a wake-up pulse, the sensor 102 in wake-up mode can remain awake and either wait for a read instruction from the microcontroller 110 to transmit its own current measurement data in response, or wait for a configuration instruction from the microcontroller 110 to change its own configuration in response.

[0224] After receiving a read command or configuration command from the microcontroller 110, the sensor 102, in wake-up mode, can connect its first and second I / O pins 102. IN 102 OUT It then switches back to the pull-up state (state 1).

[0225] A second conceivable option proposes that the sensor 102, in wake-up mode, measures a value exceeding a predefined wake-up threshold, and then sends a wake-up pulse to the microcontroller 110. In this case, the sensor 102 connects its first I / O pin 102. IN Switch to pull-down state (state 5) and set its second I / O pin 102. OUT Switch to push-pull low state (state 4) to send a wake-up pulse. Sensor 102 then remains awake and waits for a read command from microcontroller 110.

[0226] In this embodiment, the sensor 102 in wake-up mode can therefore be designed such that if the measured value obtained by the sensor 102 in wake-up mode during measurement is higher than a predetermined threshold, it stores its last obtained measured value and sends its own wake-up pulse along the daisy chain 130, and remains awake until it receives a read instruction or configuration instruction from the microcontroller 110.

[0227] After receiving a read instruction or configuration instruction from the microcontroller 110, the sensor 102, which is in wake-up mode, can connect its first and second I / O pins 102. IN 102 OUT It then switches back to the pull-up state (state 1).

[0228] Another alternative is that the microcontroller 110 sends a wake-up pulse to one or more of the sensors 101, 102, and 103 that are in wake-up mode, in order to wake the sensors 101, 102, and 103 from sleep mode. The behavior of sensors 101, 102, and 103 in wake-up mode will again be described below using sensor 102 as an example. However, it is obvious that the following description applies to all sensors 101, 102, and 103 in wake-up mode.

[0229] According to this embodiment, the sensor 102 in wake-up mode can be designed with its first I / O pin 102 IN The sensor detects a low signal level from the microcontroller 110, which will be used to signal the wake-up pulse of the sensor 102 in wake-up mode.

[0230] Sensor 102 in wake-up mode can transmit signals from the transmit pin 110 of microcontroller 110. Tx The wake-up pulse travels along daisy chain 130 toward the receive pin 110 of microcontroller 110. Rx The wake-up pulse is also relayed to the sensor 103 connected downstream in the daisy chain 130. For this purpose, the sensor 102 in wake-up mode can be designed with its first I / O pin 102... IN After detecting the wake-up pulse, it sets its second I / O pin 102. OUT The duration of the wake-up pulse is switched to a push-pull low state (state 4) so ​​that the transmit pin 110 from the microcontroller 110 can receive the wake-up pulse. Tx The wake-up pulse is in the opposite direction, that is, towards the receive pin 110 of the microcontroller 110. Rx transfer.

[0231] After detecting a wake-up pulse, the sensor 102 in wake-up mode can remain awake to wait for a read command from the microcontroller 110 to transmit its current measurement data, or to wait for a configuration command from the microcontroller 110 to change its configuration.

[0232] After receiving a read command or configuration command from the microcontroller 110, the sensor 102, in wake-up mode, can connect its first and second I / O pins 102. IN 102 OUT It then switches back to the pull-up state (state 1).

[0233] As mentioned at the beginning, sensor 102 in wake-up mode can internally transmit a wake-up pulse (originating from microcontroller 110 or other sensors 101, 103) on its two I / O pins 102. IN 102 OUT The data is transferred between the information pulse and the actual data transmission. Instead of digital data transfer originating from the information pulse or actual data transmission, the internal transfer of the wake-up pulse can also be achieved using a buffer or analog signal path. Therefore, the sensor 102 in wake-up mode can, for example, have an integrated digital buffer circuit to digitally transmit the wake-up pulse to pin 102. IN 102 OUTThe signal is transmitted between the sensor and the receiver. Alternatively or additionally, the sensor 102 in wake-up mode may have an integrated impedance transformer to transmit the wake-up pulse in analog form at pin 102. IN 102 OUT Transferred between them.

[0234] In short, then it can be based on Figure 4 The innovative DART sensors 101, 102, and 103, arranged in a ring configuration, are placed in an autonomous wake-up mode, wherein their first and second I / O pins 101 IN 101 OUT 102 IN 102 OUT 103 IN 103 OUT It should occupy at least the following states:

[0235] • First I / O pin 101 IN 102 IN 103 IN Status 1 and 5

[0236] • Second I / O pin 101 OUT 102 OUT 103 OUT : States 1 and 4

[0237] Low power mode

[0238] In addition to the wake-up mode just discussed, the innovative DART sensors 101, 102, and 103 can also be configured in low-power mode, either as alternatives or additional grounds. The low-power mode, described in detail below, can be used not only for… Figures 1 to 3 The configuration of the lines or rows and for the purposes of... Figure 4 The ring configuration is activated.

[0239] Sensor 102, which is in wake-up mode, wakes up independently and cyclically, measures and notifies microcontroller 110, while sensors 101, 102, and 103, which are in low-power mode, do not wake up on their own, but only wake up when they receive a clear wake-up signal from microcontroller 110.

[0240] If the low-power mode is activated, sensors 101, 102, and 103 in low-power mode transition to sleep mode after a measurement cycle. The current sensor configuration is stored during the sleep period. To wake sensors 101, 102, and 103 in low-power mode from sleep mode, microcontroller 110 can send a communication enable pulse to them. The delay after the communication enable pulse can be configurable (e.g., 8 μs) before microcontroller 110 sends the next instruction.

[0241] According to this implementation, the innovative DART sensors 101, 102, 103 can therefore be configured in a low-power mode, in which the sensors 101, 102, 103 can be woken up from a sleep mode by the microcontroller 110.

[0242] Sensors 101, 102, and 103 configured in low-power mode can be designed to transmit the measured values ​​obtained therein to the microcontroller 110 after a measurement is performed and then enter a sleep state. The microcontroller 110 is then awakened from the sleep state in response to a wake-up command in order to perform new actions.

[0243] Overview of the status of DART sensors

[0244] Figure 9 The feasible states of DART sensors 101, 102, and 103 are summarized in the form of state diagrams.

[0245] After DART sensors 101, 102, and 103 are turned on (box 901), they can first perform a reset and independently return to their standard values. Subsequently, DART sensors 101, 102, and 103 are in Idle State (box 902).

[0246] From there, sensors 101, 102, and 103 can receive measurement commands from microcontroller 110 (block 903). If sensors 101, 102, and 103 are not in wake-up mode, they transition to measurement mode (block 904). Subsequently, the sensors send their measured values ​​(block 905) to microcontroller 110 and, if the sensors are not in low-power mode, return directly to quiescent mode (block 902). Conversely, if the sensors are in low-power mode, sensors 101, 102, and 103 transition to low-power mode (block 911) after sending their measured values ​​(block 905) and return to quiescent mode (block 902) after receiving a communication enable pulse from microcontroller 110.

[0247] If sensors 101, 102, and 103 are in wake-up mode when they receive a measurement command (block 903), the sensors cyclically check whether they have measured a value below or above a predefined threshold (block 906). In this case, the sensor sends a wake-up pulse (transition 907) and returns to a dormant mode (block 902). In other cases (transition 908), sensors 101, 102, and 103 return to their cyclical sleep mode (block 909). The wake-up pulse can also be sent by the microcontroller 110 to return sensors 101, 102, and 103 to a dormant state (block 902).

[0248] Alternatively, sensors 101, 102, and 103 may receive configuration instructions from microcontroller 110 (block 910). If sensors 101, 102, and 103 are not in wake-up mode, they are configured according to the values ​​sent by microcontroller 110 and return to quiescent mode (block 902).

[0249] Conversely, if sensors 101, 102, and 103 are in wake-up mode upon receiving a configuration instruction (block 910), the sensors cyclically check whether they have measured values ​​below or above a predefined threshold (block 906). In this case, the sensor sends a wake-up pulse (transition 907) and returns to a quiescent mode (block 902). In other cases (transition 908), sensors 101, 102, and 103 return to their cyclical sleep mode (block 909). The wake-up pulse can also be sent by the microcontroller 110 to return sensors 101, 102, and 103 to a quiescent state (block 902).

[0250] Furthermore, sensors 101, 102, and 103 can obtain automatic addressing instructions from microcontroller 110 (block 912). In response, sensors 101, 102, and 103 are assigned individual addresses independently in sequence (block 913) and send these addresses to microcontroller 110. Subsequently, the sensors return to a static mode (block 902).

[0251] Provided that sensors 101, 102, and 103 are already addressed, they can be individually invoked by microcontroller 110 and, for example, obtain individualized measurement instructions from microcontroller 110 (block 914). The individually addressed sensors are then placed in a measurement state (block 915), where they perform one or more measurements. The sensors then send the obtained measurement results to microcontroller 110 (block 916). Subsequently, the sensors return to a rest state (block 902).

[0252] Instead of the individualized measurement commands discussed earlier, sensors 101, 102, and 103 can obtain individualized configuration commands from microcontroller 110 after successful autoaddressing (block 917). The individually addressed sensors are then configured with the values ​​transmitted by microcontroller 110 and subsequently return to a resting state (block 902).

[0253] Usage scenarios

[0254] To illustrate the DART concept in detail with examples, six different use cases are then shown, which should explain how communication takes place between the microcontroller 110 and the DART sensors 101, 102, and 103.

[0255] Use Case 1: Single DART Sensor

[0256] In this use case, a single sensor operates and communicates with the microcontroller via a DART interface. The sensor is configured such that it has its maximum measurement range without additional range bias. This use case describes a standard configuration of the sensor, therefore no reconfiguration is required.

[0257] a) No configuration is required after the sensor is turned on, because the sensor’s standard reset value corresponds to the conditions required in the said use case.

[0258] b) A new measurement is triggered by the microcontroller by pulling the TX pin up and sending a measurement command (e.g., 0x47).

[0259] c) Sensor measurements are triggered by the rising edge of the stop bit.

[0260] d) The microcontroller switches its TX pin to a tri-state state.

[0261] e) The sensor transmits its measured values ​​after the measurement is completed.

[0262] f) After receiving the measurement value, the sensor can be reconfigured or a new measurement can be triggered according to step b.).

[0263] Use Case 2: Multiple DART sensors with the same configuration

[0264] In this use case, three sensors operate via a DART interface. All sensors are configured identically, but configuration options are flexible. All sensors can simultaneously perform measurements in response to measurement commands from the microcontroller.

[0265] a) After the sensors are turned on, the microcontroller can send the desired configuration to all sensors by pulling its TX pin up.

[0266] b) A new measurement is triggered by the microcontroller by pulling the TX pin up and sending a measurement command (e.g., 0x47).

[0267] c) The sensor performs a measurement triggered by the rising edge of the stop bit.

[0268] d) The microcontroller switches its TX pin to a tri-state state.

[0269] e) The sensor transmits its corresponding measured values ​​to the microcontroller.

[0270] f) Because the three sensors are on the bus, they respond in the order described above according to their position on the bus. The first sensor, directly connected to the microcontroller, sends a notification first, followed by the sensor located behind the first sensor, and so on.

[0271] g) Only after all sensor data has been received can the sensor be reconfigured or a new measurement be triggered according to step b.

[0272] Use Case 3: Multiple DART sensors with individualized configurations of all sensors and common readouts.

[0273] Before a sensor can be accessed individually, whether for reconfiguration or reading, it must first acquire an individual address. Triggered by the auto-addressing instructions described above, all sensors are assigned addresses sequentially based on their position on the bus. Only after these addresses are assigned can individual sensor configuration be performed and individual sensor measurements triggered.

[0274] a) After the sensors are turned on, the microcontroller can first send the desired standard configuration to all sensors by pulling up its TX pin. This initially configures all sensors identically.

[0275] b) In order to enable each operation, the microcontroller first triggers individualized sensor addressing by sending an autoaddressing instruction (e.g., 0x44) to the sensor and waiting until the autoaddressing is complete.

[0276] c) For example, a second sensor can be reconfigured in a daisy chain with a configuration sent by a microcontroller by having the microcontroller switch its TX pin up and send a DART data frame with the desired configuration to such a sensor.

[0277] d) The microcontroller can trigger a new measurement by pulling its TX pin up and sending a broadcast measurement command (e.g., 0x47) to all sensors.

[0278] e) The sensor performs a measurement triggered by the rising edge of the stop bit.

[0279] f) The microcontroller switches its TX pin to a tri-state state.

[0280] g) After completing their measurements, the sensors send their measurement data to the microcontroller.

[0281] h) The sensors respond with their measured values ​​in the order described above, corresponding to their positions on the bus. The first sensor, directly connected to the microcontroller, is the first to send its measurement data to the microcontroller, followed by the sensors positioned behind it, and so on.

[0282] i) The sensor can only be reconfigured after all measurement data has been received by the microcontroller, or a new measurement can be triggered according to step d).

[0283] Use Case 4: Multiple DART sensors and individualized readings for each sensor

[0284] Before a sensor can be accessed individually, whether for reconfiguration or reading, it must first acquire an individual address. Triggered by the auto-addressing instructions described above, all sensors are assigned addresses sequentially based on their position on the bus. Only after these addresses are assigned can individual sensor configuration be performed and individual sensor measurements triggered.

[0285] In this use case, three sensors operate via the DART interface. All sensors are not configured upon activation but are used in a standard configuration. Individual measurements, in this example, are triggered only for the first sensor, which is directly connected to the microcontroller.

[0286] a) Once the sensor is turned on, no individualized configuration of the sensor is required because the standard reset value of the sensor is used in the example described.

[0287] b) In order to enable each operation, the microcontroller first triggers individualized sensor addressing by sending an autoaddressing instruction (e.g., 0x44) to the sensor and waiting until the autoaddressing is complete.

[0288] c) The first sensor is individually invoked by the microcontroller by pulling its TX pin up and sending an individualized measurement command (e.g., 0x74) followed by the sensor's address.

[0289] d) Sensor measurements are triggered by the rising edge of the stop bit.

[0290] e) The microcontroller switches its TX pin to a tri-state state.

[0291] f) After the sensor finishes measuring, it transmits its measurement data to the microcontroller.

[0292] g) Of the three sensors on the bus, only the first sensor, which is individually invoked, responds by transmitting its measurement data.

[0293] h) After the sensor's measurement data has been fully received by the microcontroller, the sensor can be reconfigured, or a new single measurement can be triggered according to step c.).

[0294] Use Case 5: Multiple DART sensors in low-power mode (requiring communication release pulses) enable)

[0295] In the described use case, multiple DART sensors operate in power-saving mode. In power-saving mode, the microcontroller must send a "communication release pulse" to end the sensor's sleep state, and then the microcontroller must wait for a pre-defined waiting time to expire before initiating new communication with the sensor.

[0296] In the described use case, a total of N sensors are involved. All sensors are configured in the same way. The sensors enter a dormant state after a measurement cycle.

[0297] a) After the sensor is turned on, the microcontroller sends a broadcast configuration instruction (e.g., 0x77) with the same configuration to all sensors by pulling up its TX pin and sending a DART data frame with the corresponding configuration to the sensor.

[0298] b) After the sensor is configured, a new measurement is triggered by the microcontroller by pulling its TX pin up and sending a broadcast measurement command (e.g., 0x47) to all sensors.

[0299] c) The sensor performs a measurement triggered by the rising edge of the stop bit.

[0300] d) In order to receive measurement data, the microcontroller switches its TX pin to a tri-state.

[0301] e) The sensor sends its measurement data to the microcontroller after the measurement is completed.

[0302] f) The first sensor, directly connected to the microcontroller, first sends its measurement data in the response sequence described above, followed by the sensors behind it, and so on.

[0303] g) After the sensor has transmitted its measurement data and the timeout period has expired, the sensor transitions to a dormant state.

[0304] h) The microcontroller can only trigger a new action after it has received all the measurement data and the sensor has been put into sleep mode.

[0305] i) However, a communication enable pulse must be sent before any new action can be taken. Then, after a waiting period, the sensor can be reconfigured, or a new measurement can be triggered according to step b.).

[0306] Use Case 6: Multiple DART sensors in wake-up mode

[0307] In the described use case, multiple sensors operate in wake-up mode. The sensors perform periodic measurements without microcontroller control. If a predefined threshold measurement value is exceeded, the sensor sends a wake-up signal to the microcontroller.

[0308] In the example, N sensors are operated via a DART interface. All sensors are configured in the same way. A threshold measurement value (or measurement range) and a loop wake-up time are set, such that the sensor wakes up, for example, every 0.8 seconds. If the measured signal is outside the threshold measurement range, a wake-up signal is sent to the microcontroller and the sensor remains awake, stores its last measurement result, and waits to be read from the stored measurement value by the microcontroller.

[0309] a) After the sensor is turned on, the microcontroller sends a broadcast configuration instruction (e.g., 0x77) with the same configuration to all sensors by pulling up its TX pin and sending a DART data frame with the corresponding configuration to the sensor.

[0310] b) The sensor transitions to wake-up mode and independently performs cyclic measurements.

[0311] c) The microcontroller switches its TX pin to a tri-state state.

[0312] d) If a wake-up event occurs, such as if the current measurement value of the sensor exceeds or falls below a preset threshold, the sensor sends a wake-up pulse, which propagates along the daisy chain through other sensors to the microcontroller.

[0313] e) All sensors in the daisy chain store their last measurements and await read instructions from the microcontroller.

[0314] f) The reading of the measurement value is triggered by the microcontroller, which pulls its TX pin up and sends a broadcast measurement command (e.g., 0x47) to all sensors.

[0315] g) The microcontroller sets its TX pin to a tri-state.

[0316] h) The sensors transmit their respective stored last measurement values ​​in the above response sequence, starting with the first sensor directly connected to the microcontroller.

[0317] i) After data transmission, the sensor directly transitions to wake-up mode according to step b).

[0318] j) To end the wake-up mode, the sensor must be reconfigured, as is possible in step f). The microcontroller may also trigger a wake-up event itself, as described in step d), to forcibly end the wake-up mode.

[0319] Summary and advantages

[0320] The concept described here (DART: Daisy Chain Asynchronous Transmitter and Receiver) is compatible with the standard UART (Universal Asynchronous Transmitter and Receiver). DART data frames 200 can be based on UART data frames (start bit 0B, first eight data bits LSB, stop bit 1B), where even more data bits are possible in DART. DART also adapts to uninitialized conditions and allows bus speeds up to 8 MBd and, in some configurations, even up to 40 MBd.

[0321] DART therefore involves an extension to the UART standard, which allows UART to be adapted to multi-sensor buses without requiring sensors to be addressed. DART is more efficient than other solutions because it can use an active push-pull configuration. This allows for significantly faster communication speeds and provides a perfect solution to ensure the responsiveness of sensors in a daisy chain, that is, on the bus. In DART, fewer wires are needed for this than in other bus systems.

[0322] DART sensors 101, 102, and 103 can be individually configurable to achieve a very good fit for different applications. DART sensors 101, 102, and 103 use the innovative concept described herein—daisy-chain asynchronous transceiver (DART)—as the communication interface with microcontroller 110.

[0323] The innovative DART interface can have the following main functions:

[0324] • Configure sensors 101, 102, and 103

[0325] • Trigger measurements from sensors 101, 102, and 103.

[0326] • Transmit the measurement data from sensors 101, 102, and 103 to the microcontroller 110

[0327] Daisy-chain communication is still possible even when all channels are down.

[0328] Innovative DART interfaces can be UART-based and, for example, have the following settings:

[0329] • Baud rate: 100kBd to 40MBd

[0330] • Start bit: Start bit (0B)

[0331] • Data: Eight bits

[0332] • Parity: None

[0333] • Stop bit: Stop bit (1B)

[0334] • Significant bits: Send the least significant bit (LSB) first.

[0335] The microcontroller 110 can change the baud rate as needed. The DART interface can be accessed after power-on in each current-supply mode. The innovative DART interface is compatible with UART in open-drain mode or push-pull tri-state mode.

[0336] To ensure data integrity, the microcontroller 110 can wait until all responses from sensors 101, 102, and 103 are received before the sensors trigger new measurements / reads or configurations. In the event of a communication failure, a restart can be performed after shutdown. After restarting, the microcontroller 110 can reconfigure sensors 101, 102, and 103.

[0337] In DART, sensors 101, 102, and 103 can be run in a daisy chain 130, with up to 128 sensors feasible at the bus. This provides feasibility for multi-sensor / array measurements. Measurements can be triggered synchronously on all sensors 101, 102, and 103. Furthermore, individualized configuration and readout at the bus participants are possible. To reduce system current consumption, the number of response bytes for sensors 101, 102, and 103 can be configured. In this way, the required data accuracy can be precisely adjusted, and unwanted status bits can be avoided.

[0338] It should be noted that the specification and drawings merely illustrate the principles of the proposed method and apparatus. Different configurations can be implemented by those skilled in the art, although such configurations are not explicitly described or shown herein; however, they embody the principles of the invention and are included within its scope. Furthermore, all examples and embodiments outlined herein are, in principle and explicitly, for illustrative purposes only, to aid the reader in understanding the principles of the proposed method and apparatus. Moreover, the conclusions drawn herein regarding the principles, aspects, and embodiments of the invention, as well as specific examples thereof, should also include their equivalents.

Claims

1. A sensor system (100) with asynchronous data transmission, wherein the sensor system (100) comprises: At least two sensors (101, 102, 103), wherein each sensor has a first I / O pin (101). IN 102 IN 103 IN ) and second I / O pin (101) OUT 102 OUT 103 OUT ), Microcontroller (110), the microcontroller having a transmit pin (110) Tx ) and receive pin (110) Rx ),as well as A single-wire data line (120) is provided, through which the microcontroller (110) can communicate with each sensor (101, 102, 103) via an asynchronous data protocol. The single-wire data line (120) is located at the transmit pin (110) of the microcontroller (110). Tx ) and receive pin (110) Rx Extending between, and Each sensor (101, 102, 103) is configured in a daisy chain (130) and sequentially connected to the single-line data line (120).

2. The sensor system (100) according to claim 1. The transmit pin (110) of the microcontroller (110) Tx It has a push-pull three-state configuration.

3. The sensor system (100) according to claim 1 or 2. The sensor system (100) is designed to enable bidirectional data communication between the microcontroller (110) and the individual sensors (101, 102, 103) via the single-wire data line (120). The transmit pin (110) of the microcontroller (110) Tx ) and receive pin (110) Rx The daisy chain (130) is connected together, and the first sensor (101) in the daisy chain (130) is connected to the transmit pin (110) of the microcontroller (110). Tx ) and receive pin (110) Rx Between, and The two I / O pins (103) of the last sensor (103) in the daisy chain (130) mentioned above. IN 103 OUT One of the I / O pins is configured as a non-contact high-impedance floating output.

4. The sensor system (100) according to claim 1. The transmit pin (110) of the microcontroller (110) Tx It has a push-pull configuration without three states, and The microcontroller (110) has a circuit (150) along with an additional enable pin (151) to enable the transmit pin (110). Tx The three states are implemented on the ).

5. The sensor system (100) according to claim 4. The sensor system (100) is designed to enable bidirectional data communication between the microcontroller (110) and the individual sensors (101, 102, 103) via the single-wire data line (120). The transmit pin (110) of the microcontroller (110) Tx ) and receive pin (110) Rx The first sensor (101) in the daisy chain (130) is connected to an additional enable pin (151), and the first sensor (101) in the daisy chain (130) is connected to a receive pin (110) of the microcontroller (110). Rx Between the ) and the additional enable pin (151), and The two I / O pins (103) of the last sensor (103) in the daisy chain (130) mentioned above. OUT One of the I / O pins is configured as a non-contact high-impedance floating output.

6. The sensor system (100) according to any one of the preceding claims. The microcontroller (110) described therein is designed to be The transmit pin (110) will be used before and during data transmission. Tx Switching to a push-pull configuration so that commands can be sent via the single-wire data line (120) to at least one of the sensors (101, 102, 103) configured in the daisy chain (130), and Before and during receiving data from each sensor (101, 102, 103), the transmit pin (110) will be... Tx Switching to a tri-state state to release the single-wire data line (120) and sequentially from the sensor (101, 102, 103) via the receive pin (110) Rx ) Receive the data.

7. The sensor system (100) according to claim 1. The transmit pin (110) of the microcontroller (110) Tx It has a push-pull configuration, and The receive pin (110) of the microcontroller (110) Rx It is configured as an open-drain input with an integrated pull-up resistor.

8. The sensor system (100) according to claim 7. The sensor system (100) is designed to enable unidirectional data communication between the microcontroller (110) and the individual sensors (101, 102, 103) via the single-wire data line (120). The first sensor (101) in the daisy chain (130) is connected to the transmit pin (110) of the microcontroller (110). Tx The daisy chain (130) is connected in series, and the last sensor (103) in the daisy chain (130) is connected to the receiver pin (110) of the microcontroller (110). Rx Connected in series.

9. A sensor system (100) with asynchronous data transmission, wherein the sensor system (100) has: At least two sensors (101, 102, 103), wherein each sensor (101, 102, 103) has a first I / O pin (101). IN 102 IN 103 IN ) and second I / O pin (101) OUT 102 OUT 103 OUT ), Microcontroller (110), the microcontroller having combined transmit and receive pins (110) DP The transmit and receive pins can internally switch between transmit and receive states. A single-wire data line (120) is provided, through which the microcontroller (110) can communicate with each sensor (101, 102, 103) via an asynchronous data protocol. The sensors (101, 102, 103) are arranged in a daisy chain (130) and sequentially connected to the single-wire data line (120), and The single-wire data line (120) is connected to the transmit and receive pins (110) of the microcontroller (110). DP The daisy chain (130) extends between the individual sensors (101, 102, 103) that are connected to form the daisy chain (130).

10. The sensor system (100) according to claim 9. The sensor system (100) is designed to enable bidirectional data communication between the microcontroller (110) and the individual sensors (101, 102, 103) via the single-wire data line (120). The transmit and receive pins (110) of the combination of the first sensor (101) in the daisy chain (130) and the microcontroller (110) DP ) connect, and The two I / O pins (103) of the last sensor (103) in the daisy chain (130) mentioned above. OUT One of the I / O pins is configured as a non-contact high-impedance floating output.

11. The sensor system (100) according to any one of claims 1 to 6, 9 or 10. The sensors (101, 102, 103) configured in the daisy chain (130) are designed in hardware such that not only their respective first I / O pins (101) are configured to be compatible with the daisy chain (130), the sensors (101, 102, 103) are configured to be compatible with the daisy chain (130). IN 102 IN 103 IN At its corresponding second I / O pin (101) OUT 102 OUT 103 OUT Each of the following states occupies at least one of the following states: • Pull-up state, in which the corresponding I / O pin (101) is in the pull-up state. IN 102 IN 103 IN 101 OUT 102 OUT 103 OUT It is pulled high by a resistor and can only be pulled low through an external ground connection. • Push-pull high state, in which the corresponding I / O pin (101) IN 102 IN 103 IN 101 OUT 102 OUT 103 OUT The signal is pulled high so that the connected components are also pulled high. • Push-pull low state, in which the corresponding I / O pin (101) IN 102 IN 103 IN 101 OUT 102 OUT 103 OUT The circuit is pulled low so that the connected components are also pulled low.

12. The sensor system (100) according to claim 11. The microcontroller (110) is designed to send measurement commands via the single-wire data line (120) to the sensors (101, 102, 103) arranged in the daisy chain (130) to transmit signals to the sensors (101, 102, 103) indicating that a measurement has been performed, and The sensors (101, 102, 103) are designed to perform measurements in response to measurement commands, and the measurement data obtained therein are transmitted sequentially to the microcontroller (110) along the daisy chain (130) in a preset response order.

13. The sensor system (100) according to claim 12. The sensors (101, 102, 103) are designed to transmit their measurement data to the microcontroller (110) in ascending response order, starting with the sensor (101) closest to the microcontroller (110) and ending with the sensor (103) furthest from the microcontroller (110).

14. The sensor system (100) according to claim 12 or 13. The sensors (101, 102, 103) are designed to connect their first I / O pin (101) to the sensor after receiving the measurement command. IN 102 IN 103 IN Switch it to pull-up state and set its second I / O pin (101) to pull-up state. OUT 102 OUT 103 OUT Switch to push-pull low mode. If the sensor (102) located at position X in the daisy chain (130) is on its first I / O pin (102) IN The sensor sends its measurement data toward the microcontroller (110) only when a high signal level is received at a location (101) directly adjacent to the microcontroller (110), wherein the high signal level comes either from the sensor (101) directly adjacent to the microcontroller (110) or from the microcontroller (110) itself. The sensor (102) located at position X is designed to transmit its measurement data via its first I / O pin (102). IN The second I / O pin (102) switches between the push-pull high state and the push-pull low state. OUT It remains in the push-pull low state.

15. The sensor system (100) according to claim 14. The sensor (102) located at position X is designed to not only transmit measurement data to its first I / O pin (102) after successful transmission of measurement data. IN And its second I / O pin (102) OUT Switch to pull-up state so that a signal can be transmitted to the sensor (103) directly adjacent to the microcontroller (110) by means of a high signal level: now it is the adjacent sensor (103)'s turn to send its measurement results.

16. The sensor system (100) according to claim 15. The sensor (102) located at position X is designed to transmit measurement data from the adjacent sensor (103) along the daisy chain (130) toward the microcontroller (110) in such a way that the sensor transmits the measurement data from its second I / O pin (102) to the microcontroller (110). OUT The signal level received from the adjacent sensor (103) during the reception of measurement data at its first I / O pin (102) is... IN Mapping at ) 17. The sensor system according to claim 16, The sensor (102) located at position X is designed as follows: During the period of receiving measurement data from the adjacent sensor (103), for the duration of the received low signal level, its first I / O pin (102) is... IN Switch to push-pull low mode, and During the period of receiving measurement data from the adjacent sensor (103), for the duration of the received high signal level, its first I / O pin (102) is... IN Then it switches back to the pull-up state.

18. The sensor system (100) according to claim 15. The sensor (102) located at position X is designed to receive measurement data from the adjacent sensor (103). In digital form, using integrated digital buffer circuitry, or In analog form, using an integrated impedance transformer Its first and second I / O pins (102) IN 102 OUT The data is transmitted between the daisy chain (130) and the microcontroller (110) so that the acquired measurement data is transferred along the daisy chain (130) toward the microcontroller (110).

19. The sensor system (100) according to any one of claims 12 to 18. The microcontroller (110) is designed to wait for the full acquisition of measurement data from the sensors (101, 102, 103) configured in the daisy chain (130) before sending additional instructions to the sensors (101, 102, 103).

20. The sensor system (100) according to any one of claims 11 to 19. The sensors (101, 102, 103) are configurable in an autonomous wake-up mode, in which they independently and autonomously wake up from a sleep mode. The sensors (101, 102, 103) that can be configured in the wake-up mode are designed to be It wakes from sleep at a predetermined repetition rate without explicit measurement instructions from the microcontroller (110) in order to perform measurements independently, and then returns to sleep after a successful measurement.

21. The sensor system (100) according to claim 20. The sensor (102) located within the daisy chain (130) in the wake-up mode is designed to, after being placed in the wake-up mode, have its first I / O pin (102)... IN ) and its second I / O pin (102) OUT Switch to pull-up mode.

22. The sensor system (100) according to claim 20 or 21. The sensor (102) in the wake-up mode is designed to be positioned on its first or second I / O pin (102). IN 102 OUT The detection originates from a low signal level originating from a directly adjacent sensor (101, 103), wherein the low signal level marks a wake-up pulse, and The sensor (102) in the wake-up mode is designed to be positioned on its first or second I / O pin (102). IN 102 OUT After the wake-up pulse is detected at ) location, the corresponding other I / O pins (102) will be activated. IN 102 OUT During the duration of receiving the wake-up pulse, the sensor switches to a push-pull low state to relay the wake-up pulses of the adjacent sensors (101, 103) in the opposite direction. The sensor (102) in the wake-up mode remains awake after the wake-up pulse is transmitted, and Waiting for a read instruction from the microcontroller (110) in order to transmit its own current measurement data in response, or Wait for configuration instructions from the microcontroller (110) in order to change its own configuration in response.

23. The sensor system (100) according to claim 22. The sensor (102) in the wake-up mode is designed to receive wake-up pulses originating from the directly adjacent sensors (101, 103). In digital form, using integrated digital buffer circuitry, or In analog form, using an integrated impedance transformer Its first and second I / O pins (102) IN 102 OUT The pulses are transmitted between the adjacent sensors (101, 103) so as to relay the wake-up pulses of the adjacent sensors in the opposite direction.

24. The sensor system (100) according to claim 20 or 21. The sensor (102) in the wake-up mode is designed to be positioned on its first I / O pin (102). IN The system detects a low signal level originating from the microcontroller (110), wherein the low signal level is used to signal a wake-up pulse for the sensor (102) in the wake-up mode. The sensor in the wake-up mode is designed to be located on its first I / O pin (102). IN After detecting the wake-up pulse at point 102, its second I / O pin (102) is then... OUT During the duration of receiving the wake-up pulse, the device switches to a push-pull low state to redirect the wake-up pulse from the direction of the microcontroller (110) in the opposite direction. The sensor (102) in the wake-up mode remains awake after detecting the wake-up pulse, and Waiting for a read instruction from the microcontroller (110) in order to transmit its own current measurement data in response, or Wait for configuration instructions from the microcontroller (110) in order to change its own configuration in response.

25. The sensor system (100) according to claim 20 or 21. The sensor (102) in the wake-up mode is designed to receive wake-up pulses originating from the microcontroller (110). In digital form, using integrated digital buffer circuitry, or In analog form, using an integrated impedance transformer Its first and second I / O pins (102) IN 102 OUT The pulse is transmitted between the microcontroller (110) so that the wake-up pulse from the direction of the microcontroller (110) is transmitted in the opposite direction.

26. The sensor system (100) according to claim 20 or 21. The sensor (102) in the wake-up mode is designed to be If the sensor (102) in wake-up mode obtains a measurement value higher than a predetermined threshold during measurement, it stores the last obtained measurement value and sends its own wake-up pulse along the daisy chain (130), and remains awake until it receives a read instruction or configuration instruction from the microcontroller (110).

27. The sensor system (100) according to claim 26. The sensor (102) in the wake-up mode is designed to send the wake-up pulse to its first and second I / O pins (102). IN 102 OUT Switch to push-pull low mode.

28. The sensor system (100) according to any one of claims 22, 24 or 27. The sensor (102) in the wake-up mode is designed to connect its first and second I / O pins (102) after receiving the read command or the configuration command. IN 102 OUT Then it switches back to the pull-up state.

29. The sensor system according to claim 7 or 8, The sensors configured in the daisy chain are designed in hardware to occupy at least one of the following states not only at their respective first I / O pin (IN) but also at their respective second I / O pin (OUT): • Pull-up state, in which the corresponding I / O pin (101) is in the pull-up state. IN 102 IN 103 IN 101 OUT 102 OUT 103 OUT It is pulled high by a pull-up resistor and can only be pulled low through an external ground connection. • Push-pull high state, in which the corresponding I / O pin (101) IN 102 IN 103 IN 101 OUT 102 OUT 103 OUT The signal is pulled high so that the connected components are also pulled high. • Tri-state, in which the corresponding I / O pin (101) IN 102 IN 103 IN 101 OUT 102 OUT 103 OUT Configured as a non-contact, high-resistance floating connector to ensure that the connected components have the same voltage level. • Push-pull low state, in which the corresponding I / O pin (101) IN 102 IN 103 IN 101 OUT 102 OUT 103 OUT The signal is pulled low so that the connected components are also pulled low. • Pull-down state, in which the corresponding I / O pin (101) IN 102 IN 103 IN 101 OUT 102 OUT 103 OUT It is pulled low by a pull-down resistor and can only be pulled high by an external operating voltage connection.

30. The sensor system (100) according to claim 29. The microcontroller (110) is designed to send measurement commands via the single-wire data line (120) to the sensors (101, 102, 103) arranged in the daisy chain (130) to transmit signals to the sensors (101, 102, 103) indicating that a measurement has been performed, and The sensors (101, 102, 103) are designed to perform measurements in response to the measurement command and transmit the measurement data obtained therein sequentially along the daisy chain (130) to the microcontroller (110) in a preset response order.

31. The sensor system (100) according to claim 30. The sensors (101, 102, 103) are designed to transmit their measurement data in a descending order of response, i.e., to the receiver pin (110) closest to the microcontroller (110). Rx The positioning sensor (101) (regarding the connection order in the daisy chain) starts from the nearest transmitting pin (110) to the microcontroller (110). Tx The sensor (103) for positioning transmits the data to the microcontroller (110).

32. The sensor system (100) according to claim 30 or 31. The sensor configured in the daisy chain is designed to activate its first I / O pin (101) after receiving the measurement command. IN 102 IN 103 IN Switch it to pull-down mode and set its second I / O pin (101) to pull-down mode. OUT 102 OUT 103 OUT Switch to pull-up state, where the pull-up resistor is at least larger than the pull-down resistor, large enough to pull the value generated in the potentiometer to a defined signal level.

33. The sensor system (100) according to claim 32. The transmit pin (110) closest to the microcontroller (110) Tx The sensor (101) is positioned via its first I / O pin (101). IN A high signal level signal originating from the microcontroller (110) is detected at the location, indicating via signaling that it is at the end of the response sequence, and The transmit pin (110) closest to the microcontroller (110) Tx The positioning sensor (101) is designed to randomly place its first I / O pin (101) IN Switch to the tri-state.

34. The sensor system (100) according to claim 32 or 33. The sensor (102) located at position X in the daisy chain (130) communicates with the sensor via its second I / O pin (102). OUT A high signal level was detected at ( ) and signaled to indicate that it is the next sensor in the response sequence, so as to transmit its measurement data, and The sensor (102) located at position X is designed to transmit its measurement data via its second I / O pin (102). OUT The first I / O pin (102) switches between push-pull high and push-pull low states. IN (Keep it in the drop-down state.) 35. The sensor system according to claim 34, The sensor (102) located at position X is designed to send its first I / O pin (102) after successfully transmitting the measurement data. IN Switching to a tri-state state allows a signal to be sent toward the transmit pin (110) of the microcontroller (110) via a high signal level. Tx The directly adjacent sensor (101) is passed on: it is the next sensor in the response sequence, in order to transmit its measurement data, and The adjacent sensor (101) is designed to transmit its measurement data in response to a received high signal level.

36. The sensor system according to claim 35, The sensor (102) located at position X is designed to transmit measurement data from the adjacent sensor (101) along the daisy chain (130) toward the receiving pin (110) of the microcontroller (110). Rx The data is transmitted via the sensor's first I / O pin (102) during the reception of measurement data. OUT The signal level received from the adjacent sensor (101) at pin 102 is mapped to its second I / O pin (102). OUT ) place.

37. The sensor system (100) according to claim 36. The sensor (102) located at position X is designed as follows: During the period of receiving measurement data from the adjacent sensor (101), for the duration of the received low signal level, its second I / O pin (102) is... OUT Switch to push-pull low mode, and During the period of receiving measurement data from the adjacent sensor (103), the second I / O pin (102) is used for the duration of the received high signal level. OUT It then switches back to the push-pull high state.

38. The sensor system (100) according to claim 35. The sensor (102) located at position X is designed to transmit data via a pin (110) towards the microcontroller (110). Tx Measurement data obtained from directly adjacent sensors (101) In digital form, using integrated digital buffer circuitry, or In analog form, using an integrated impedance transformer Its first and second I / O pins (102) IN 102 OUT The acquired measurement data is transmitted between the microcontroller (110) and the receiver pin (110) of the microcontroller (110) along the daisy chain (130). Rx )transfer.

39. The sensor system (100) according to any one of claims 30 to 38. The microcontroller (110) is designed to wait for the full acquisition of measurement data from the sensors (101, 102, 103) configured in the daisy chain (130) before sending additional instructions to the sensors (101, 102, 103).

40. The sensor system (100) according to any one of claims 29 to 39. The sensors (101, 102, 103) are configurable in an autonomous wake-up mode, in which they independently and autonomously awaken from a sleep mode. The sensors (101, 102, 103) that can be configured in the wake-up mode are designed to be It wakes up from sleep at a predetermined repetition rate without explicit measurement instructions from the microcontroller (110) in order to perform measurements independently, and then returns to sleep after a successful measurement.

41. The sensor system (100) according to claim 40. The sensor (102) located within the daisy chain (130) in the wake-up mode is designed to, after being placed in the wake-up mode, have its first I / O pin (101)... IN 102 IN 103 IN ) and its second I / O pin (101) OUT 102 OUT 103 OUT Switch to pull-up mode.

42. The sensor system (100) according to claim 40 or 41. The sensor (102) in the wake-up mode is designed to be positioned on its first I / O pin (102). IN The probe originates from the transmit pin (110) of the microcontroller (110). Tx The low signal level of the directly adjacent sensor (101), wherein the low signal level marks a wake-up pulse, and The sensor (102) in the wake-up mode is designed to be positioned on its first I / O pin (102). IN After detecting the low signal level at ) , its second I / O pin (102) OUT The duration of receiving the wake-up pulse is switched to a push-pull low state so that the received wake-up pulse is directed along the daisy chain (130) toward the receive pin (110) of the microcontroller (110). Rx Forward, and The sensor (102) in the wake-up mode then remains awake and Waiting for a read instruction from the microcontroller (110) in order to transmit its own current measurement data in response, or Wait for configuration instructions from the microcontroller (110) in order to change its own configuration in response.

43. The sensor system (100) according to claim 42. The sensor (102) in the wake-up mode is designed to transmit signals originating from the transmit pin (110) directed toward the microcontroller (110). Tx wake-up pulse of the directly adjacent sensor (101) In digital form, using integrated digital buffer circuitry, or In analog form, using an integrated impedance transformer Its first and second I / O pins (102) IN 102 OUT The wake-up pulse is transmitted between the microcontroller (110) and the receiver pin (110) of the microcontroller (110) along the daisy chain (130). Rx )transfer.

44. The sensor system (100) according to any one of claims 41 to 43. The sensor (102) in the wake-up mode is designed to be located on its second I / O pin (102). OUT The detection originates from the receive pin (110) of the microcontroller (110). Rx The low signal level of the directly adjacent sensor (103), wherein the low signal level marks a wake-up pulse, and The sensor (102) in the wake-up mode is designed to be located on its second I / O pin (102). OUT After detecting the low signal level at ) location, its first I / O pin (102) is then... IN The duration of receiving the wake-up pulse is switched to a pull-down state so that the received wake-up pulse is directed along the daisy chain (130) toward the transmit pin (110) of the microcontroller (110). Tx Forward, and The sensor (102) in the wake-up mode then remains awake and Waiting for a read instruction from the microcontroller (110) in order to transmit its own current measurement data in response, or Wait for configuration instructions from the microcontroller (110) in order to change its own configuration in response.

45. The sensor system (100) according to claim 44. The sensor (102) in the wake-up mode is designed to receive signals from the receiver pin (110) facing the microcontroller (110). Rx wake-up pulse of the directly adjacent sensor (103) In digital form, using integrated digital buffer circuitry, or In analog form, using an integrated impedance transformer On its second I / O pin (102) OUT ) and its first I / O pin (102) IN The wake-up pulse is transmitted between the microcontroller (110) and the daisy chain (130) towards the transmit pin (110) of the microcontroller (110). Tx )transfer.

46. ​​The sensor system (100) according to claim 40 or 41. The sensor (102) in the wake-up mode is designed to be positioned on its first I / O pin (102). IN The probe originates from the transmit pin (110) of the microcontroller (110). Tx The low signal level of the sensor (102) in the wake-up mode is used to signal a wake-up pulse for the sensor (102) in the wake-up mode. The sensor (102) in the wake-up mode is designed to be positioned on its first I / O pin (102). IN After detecting the wake-up pulse at point 102, its second I / O pin (102) is then... OUT The duration of receiving the wake-up pulse is switched to a push-pull low state so that the wake-up pulse of the microcontroller (110) is directed along the daisy chain (130) toward the receive pin (110) of the microcontroller (110). Rx Forward, and The sensor (102) in the wake-up mode remains awake after detecting the low signal level and Waiting for a read instruction from the microcontroller (110) in order to transmit its own current measurement data in response, or Wait for configuration instructions from the microcontroller (110) in order to change its own configuration in response.

47. The sensor system (100) according to claim 46. The sensor (102) in the wake-up mode is designed to receive wake-up pulses originating from the microcontroller (110). In digital form, using integrated digital buffer circuitry, or In analog form, using an integrated impedance transformer Its first and second I / O pins (102) IN 102 OUT The wake-up pulse is transmitted between the microcontroller (110) and the receiver pin (110) of the microcontroller (110) along the daisy chain (130). Rx )transfer.

48. The sensor system (100) according to claim 40 or 41. The sensor (102) in the wake-up mode is designed to be If the sensor (102) in the wake-up mode obtains a measurement value higher than a predetermined threshold during measurement, it stores the last obtained measurement value and sends its own wake-up pulse along the daisy chain (130), and remains awake until it receives a read instruction or configuration instruction from the microcontroller (110).

49. The sensor system (100) according to claim 48. The sensor (102) in the wake-up mode is designed to send the wake-up pulse to the microcontroller (110) to activate its first I / O pin (102). IN Switch it to pull-down mode and set its second I / O pin (102) to pull-down mode. OUT Switch to push-pull low mode.

50. The sensor system (100) according to claim 42, 44 or 49. The sensor (102) in the wake-up mode is designed to connect its first and second I / O pins (102) after receiving a read instruction or configuration instruction from the microcontroller (110). IN 102 OUT Then it switches back to the pull-up state.

51. The sensor system (100) according to any one of the preceding claims. The sensors (101, 102, 103) each have exactly two I / O pins (101, 102, 103). IN 101 OUT ;102 IN 102 OUT ;103 IN 103 OUT The sensor is connected in a daisy chain (130) by means of the two I / O pins.

52. The sensor system (100) according to any one of the preceding claims. No external devices are provided in the section of the single-line data line (120) extending between the microcontroller (110) and the first sensor (101) in the daisy chain (130).

53. The sensor system (100) according to any one of the preceding claims. The first sensor (101) in the daisy chain (130) is directly connected to the microcontroller (110), and the single-wire data line (120) is connected to the first I / O pin (101) of the microcontroller (110) and the first sensor (101). IN Extending between, and The second sensor (102) in the daisy chain (130) is directly connected to the first sensor (101), and the single-wire data line (120) is connected to the second I / O pin (101) of the first sensor (101). OUT ) and the first I / O pin (102) of the second sensor (102) IN Extending between ).

54. The sensor system (100) according to any one of the preceding claims. The microcontroller (110) is designed to send instructions to the sensors (101, 102, 103) in the daisy chain (130) via the single-wire data line (120), and Each instruction is encoded in a data frame (200) having a start bit (210) and a stop bit (220) and at least eight data bits (201, 202, ..., 208) in between.

55. The sensor system (100) according to claim 54. The data frame (200) is compatible with the UART protocol.

56. The sensor system (100) according to any one of claims 54 or 55. The microcontroller (110) is designed to transmit data frames (200) with variable baud rates up to 40 MBd on the single-wire data line (120).

57. The sensor system (100) according to any one of claims 54 to 56. The microcontroller (110) is designed to change the baud rate between transmissions of two data frames (200) on the single-wire data line (120).

58. The sensor system (100) according to any one of claims 54 to 57. The microcontroller (110) is designed to integrate at least one synchronization pulse (301, 302) in the data frame (200), the synchronization pulse indicating the currently selected baud rate, and The sensors (101, 102, 103) configured as the daisy chain (130) are designed to determine the baud rate selected by the microcontroller (110) based on the synchronization pulses (301, 302) integrated in the data frame (200) so as to synchronize with the microcontroller (110).

59. The sensor system (100) according to claim 58. The synchronization pulses (301, 302) are characterized by two edge transitions that are fixedly spaced apart from each other in the same direction, and The valid data contained in the data frame (200) is set between the synchronization pulses (301, 302).

60. The sensor system according to claim 58 or 59, The relationship between the duration of the low and high signal levels of the synchronization pulses (301, 302) encodes the corresponding instructions sent by the microcontroller (110) to the sensors (101, 102, 103) configured in the daisy chain (130).

61. The sensor system (100) according to any one of the preceding claims. The microcontroller (110) is designed to send configuration instructions to all sensors (101, 102, 103) in the daisy chain (130) via the single data line (120) so that all sensors (101, 102, 103) have the same configuration.

62. The sensor system (100) according to any one of the preceding claims. The microcontroller (110) is designed to individually address at least one of the sensors (101, 102, 103) in the daisy chain (130) via a single-wire data line (120) and send individualized measurement instructions to the sensor so as to signal to the sensor that the measurement is performed independently of the other sensors in the daisy chain (130).

63. The sensor system (100) according to any one of the preceding claims. The microcontroller (110) is designed to individually address at least one of the sensors (101, 102, 103) in the daisy chain via the single-wire data line (120) and to send individualized configuration instructions to the sensor so as to configure the sensor independently of the other sensors in the daisy chain (130).

64. The sensor system (100) according to any one of claims 62 or 63. The microcontroller (110) is designed to perform an automatic addressing process before the sensors (101, 102, 103) are individually addressed, during which the sensors (101, 102, 103) in the daisy chain (130) are each assigned an individual address. The microcontroller (110) is designed to send autoaddress instructions to sensors (101, 102, 103) configured in the daisy chain (130) via the single-wire data line (120). Each sensor (101, 102, 103) has an integrated counter whose reading represents the individual address of the corresponding sensor (101, 102, 103), and each sensor (101, 102, 103) responds to an automatic addressing instruction by independently incrementing its counter reading. The automatic addressing instructions are processed sequentially by the sensors (101, 102, 103) in such a way that the counter readings of the sensors (101, 102, 103) are incremented by one bit according to the number of sensors following them in the daisy chain (130), such that after a successful automatic addressing process, the first sensor (101) in the daisy chain (130) has the highest counter reading and the last sensor in the daisy chain (130) has the lowest counter reading.

65. The sensor system (100) according to claim 64. The microcontroller (110) is designed to count the actual number of sensors (101, 102, 103) that are self-addressed in response to auto-addressing instructions and compare them with the known expected number of sensors in the daisy chain (130). Further instructions are sent only after the automatic addressing process has ended.

66. The sensor system (100) according to any one of the preceding claims. The sensors (101, 102, 103) are configured in a low-power mode, in which they are woken from a sleep mode by the microcontroller (110). The sensors (101, 102, 103) configured in the low-power mode are designed to be After the measurement is performed, the obtained measurement value is transmitted to the microcontroller (110) and then the system enters a dormant state. The device is awakened from sleep in response to a wake-up command received from the microcontroller (110) in order to perform new actions.

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