Sensing device and main control device

Abstract

A sensing device and a master control device are provided. The sensing device includes: a sensing information transmission circuit, a control information slave circuit, and a mode switching circuit. The sensing information transmission circuit is used to convert sensing information into a transmission signal conforming to a signal format of a first transmission protocol. The control information slave circuit is used to convert a received signal from a signal transmission interface into control information according to a second transmission protocol, thereby setting the sensing device. The mode switching circuit is used to activate one of the sensing information transmission circuit and the control information slave circuit based on a signal on a clock channel, a signal on a data channel, or a signal on a power rail of the sensing device on the signal transmission interface, so that it can transmit or receive signals through the signal transmission interface.

Description

Technical Field

[0001] This invention relates to signal transmission, and more particularly to a transmission control architecture that uses a single signal transmission interface to transmit signals of multiple transmission protocols between a main control device and a sensing device. Background Technology

[0002] Modern digital microphones, such as those from Micro-electromechanical Systems (MEMS) devices, typically rely on Pulse-Density Modulation (PDM) interfaces to transmit audio signals. PDM interfaces usually have a 1-bit data channel and a clock channel, transmitting signals sequentially. However, PDM interfaces themselves lack control channels and cannot transmit control parameters related to the digital microphone. Consequently, the acoustic-electrical characteristics of a digital microphone cannot be changed after it leaves the factory, such as sampling rate, sensitivity, acoustic overload point (AOP), or filter settings. Therefore, if adjustments to a digital microphone are required, a transmission protocol with in-band control is needed, such as the MIPI (MIPISoundWire) audio interface or the / HD-Audio interface, or additional signal pins must be added. However, both of these methods increase system cost and circuit complexity. Summary of the Invention

[0003] In view of this, one objective of the present invention is to provide an integrated data / control interface that uses existing signal transmission interfaces for sensing information to transmit sensing and control information separately in a time-division multiplexing manner, thereby controlling the sensing device and reading its sensing information to achieve setting / characteristic adjustment of the sensing device. Because the architecture of the present invention effectively integrates different signal transmission interfaces, it does not lead to a significant increase in cost.

[0004] An embodiment of the present invention provides a sensing device. The sensing device includes: a sensing information transmission circuit, a control information slave circuit, and a mode switching circuit. The sensing information transmission circuit is used to convert sensing information into a transmission signal conforming to a signal format of a first transmission protocol. The control information slave circuit is used to convert a received signal from a signal transmission interface into control information according to a second transmission protocol, thereby setting the sensing device. The mode switching circuit is coupled to the sensing information transmission circuit and the control information slave circuit, and is used to activate one of the sensing information transmission circuit and the control information slave circuit based on a signal on a clock channel, a signal on a data channel, or a signal on a power rail of the sensing device on the signal transmission interface, to transmit or receive signals through the signal transmission interface.

[0005] An embodiment of the present invention provides a master control device. The master control device includes: a sensing information receiving circuit, a control information main circuit, and a mode switching circuit. The sensing information receiving circuit is used to convert a received signal from a signal transmission interface into sensing information according to a first transmission protocol. The control information main circuit is used to convert the control information into a transmission signal conforming to the signal format of the second transmission protocol according to a second transmission protocol. The mode switching circuit is coupled to the sensing information receiving circuit and the control information main circuit, and is used to adjust the signal on a clock channel, a data channel, or a power rail of the sensing device on the signal transmission interface according to an operating mode of the master control device, and to control either the sensing information receiving circuit or the control information main circuit to use the signal transmission interface for signal reception or transmission. Attached Figure Description

[0006] Figure 1 This diagram illustrates the architecture of the main control device and the sensing device in an embodiment of the present invention.

[0007] Figure 2 A detailed architectural diagram of the pattern detection circuit in an embodiment of the present invention is shown.

[0008] Figure 3 The following is a signal timing diagram from an embodiment of the present invention.

[0009] Figure 4 A schematic diagram of hysteresis control in an embodiment of the present invention is shown.

[0010] Figure 5 This diagram illustrates the detailed architecture of the master control device simultaneously controlling and accessing multiple sensing devices in an embodiment of the present invention. Detailed Implementation

[0011] Numerous specific details are described below to provide the reader with a thorough understanding of embodiments of the invention. However, those skilled in the art will appreciate how the invention can be implemented in the absence of one or more specific details, or by utilizing other methods, elements, or materials. In other instances, well-known structures, materials, or operations are not shown or described in detail to avoid obscuring the core concepts of the invention.

[0012] The phrase "in one embodiment" in this specification means that a particular feature, structure, or characteristic described in that embodiment may be included in at least one embodiment of the invention. Therefore, the phrase "in one embodiment" appearing throughout this specification does not necessarily mean the same embodiment. Furthermore, the aforementioned particular features, structures, or characteristics may be combined in any suitable form in one or more embodiments.

[0013] Please refer to Figure 1 This figure illustrates a master control device and a sensing device using the signal transmission interface of the present invention in an embodiment of the invention. The master control device 100 can communicate with one or more sensing devices 200 through the signal transmission system of the present invention, thereby realizing the setting adjustment of one or more sensing devices 200 and the reading of sensing data. In some embodiments, the signal transmission interface 300 includes at least a first channel 310 and a second channel 320. The first channel 310 can be used to transmit clock signals, and the second channel 320 can be used to transmit data signals, but is not limited thereto.

[0014] The main control device 100 includes a sensing information receiving circuit 110, a control information main circuit 120, and a mode switching circuit 130. The sensing information receiving circuit 110 is used to convert signals received from the second channel 320 into specific sensing information, such as audio information, vibration information, pressure information, optical information, or temperature information, based on a clock signal on the first channel 310, according to a first transmission protocol. In one embodiment, the first transmission protocol may be a pulse density modulation (PDM) based transmission protocol. The control information main circuit 120 is used to send control information to the sensing device 200 through at least one of the first channel 310 or the second channel 320 according to a second transmission protocol. The second transmission protocol may be a synchronous transmission protocol or an asynchronous transmission protocol. For example, a synchronous transmission protocol may be I... 2C can be either the Serial Peripheral Interface (SPI) protocol, or the asynchronous transmission protocol can be a Universal Asynchronous Receiver / Transmitter (UART) or a 1-wire protocol. When the second transmission protocol is synchronous, the control information main circuit 120 transmits clock signals through the first channel 310 and control information through at least the second channel 320 (multiple non-clock channels may be needed for communication depending on the requirements of the transmission protocol). When the second transmission protocol is asynchronous, the control information main circuit 120 can transmit control information through one of the first channel 310 or the second channel 320 (such as 1-wire or UART single-ended transmission protocol), or both (such as UART differential transmission protocol). The mode switching circuit 130 can switch the usage rights of the first channel 310 and the second channel 320 between the sensing information receiving circuit 110 and the control information main circuit 120 according to the needs of the main control device 100. In different embodiments of the present invention, the mode switching circuit 130 can change the signal frequency on the first channel 310, the signal characteristics on the second channel 320, or the voltage level on a power rail 400, thereby notifying the sensing device 200 in advance whether the current master control device 100 is entering a setting adjustment mode, in which the control information main circuit 120 transmits control information using the signal transmission interface 300, or whether the current master control device 100 is entering a sensing information reading mode, in which the sensing information receiving circuit 110 receives sensing information using the signal transmission interface 300. In one embodiment, when the control information main circuit 120 wants to transmit control information to the sensing device 200 through the signal transmission interface 300, the mode switching circuit 130 can transmit a signal with a frequency lower than a threshold value on the first channel 310, or increase the voltage level on the power rail 400. In this way, the sensing device 200 can determine that the transmitted signal on the signal transmission interface 300 is control information, and thus call the corresponding circuit module to process the signal on the channel. Conversely, when the control information main circuit 120 wants to receive sensing information through the signal transmission interface 300, the mode switching circuit 130 can transmit a signal with a frequency higher than the threshold value on the first channel 310, or reduce the voltage level on the power rail 400, thereby allowing the sensing device 200 to call the corresponding circuit module to transmit sensing information. Please note that the above-described method is only one embodiment of the present invention, and this embodiment is suitable for a base clock of the first transmission protocol (e.g., PDM) to be higher than that of the second transmission protocol (e.g., I...). 2C) Base Clock. In other embodiments, if the base clock of the first transmission protocol is lower than the base clock of the second transmission protocol, the sensing device 200 can be notified of the switching of the operating mode in the opposite manner. For example, before transmitting control information, the mode switching circuit 130 can transmit a signal with a frequency higher than a threshold value on the first channel 310, or lower the voltage level on the power rail 400, so that the sensing device 200 can determine that the transmitted signal on the signal transmission interface 300 is control information. Conversely, before receiving sensing information, the mode switching circuit 130 can transmit a signal with a frequency lower than the threshold value on the first channel 310, or raise the voltage level on the power rail 400, so that the sensing device 200 calls the corresponding circuit module to transmit sensing information. In other words, in the embodiments of the present invention, the relationship between the signal frequency on the first channel 310 and the frequency threshold value, or the relationship between the voltage level on the power rail 400 and the voltage threshold value, can reflect whether the main control device 100 is in the setting adjustment mode or the sensing information reading mode.

[0015] In addition to the methods described above, in other embodiments of the present invention, the main control device 100 can also notify the sensing device 200 of mode switching through signal characteristics on the second channel 320. For example, the mode switching circuit 130 can transmit a signal with a specific pattern on the second channel 320 to the sensing device 200 within a specific time interval to inform the sensing device 200 of the current operating mode of the main control device 100, enabling it to respond appropriately. For example, the main control device 100 and the sensing device 200 can pre-set / agree on encoding / decoding rules and signal patterns. When the sensing device 200 decodes the packet from the main control device 100, and the content of the decoded packet corresponds to a pre-agreed simple signal content or a series of continuous signal content (e.g., but not limited to, the signal content displays a continuous sequence of up, down, down, left, right, left, right, BA (before being converted to binary)... or a specific signal pattern such as 11011100), the sensing device 200 can determine that the transmitted signal on the signal transmission interface 300 is control information, and thus call the corresponding circuit module to process the signal on the second channel 320.

[0016] The sensing device 200 includes a sensing information transmission circuit 210, a control information slave circuit 220, and a mode switching circuit 230. The sensing information transmission circuit 210 is used to convert the sensing signal generated by the sensing module 240, based on the clock signal on the first channel 310, into a data signal on the second channel 320, and transmit it to the main control device 100 according to the first transmission protocol. In one embodiment, the sensing module 240 (when the sensing device 200 is a digital microphone) may include a sound-to-electric conversion device, an analog-to-digital converter, and a signal processing circuit. In another embodiment, the sensing module 240 (e.g., when the sensing device 200 is a temperature sensing device) may include a thermoelectric conversion device, an analog-to-digital converter, and a signal processing circuit, but is not limited thereto. Furthermore, in more embodiments of the present invention, the sensing module 240 may also be a vibration sensor, a pressure sensor, or an optical sensor. Furthermore, the control information from circuit 220 is used to convert signals received from at least one of the first channel 310 or the second channel 320 into control information according to the second transmission protocol, thereby setting and adjusting other circuit elements in the sensing module 240 or sensing device 200. The setting parameters used by one or more elements in the sensing module 240 or sensing device 200 can be adjusted by the control information. In one embodiment, these setting parameters may include (but are not limited to): sampling rate, sensitivity, gain control, acoustic overload point (AOP), or filter settings, etc. Furthermore, the mode switching circuit 230 includes a mode detection circuit 232 and a mode control circuit 234. The mode detection circuit 232 can determine whether the current operating mode of the main control device 110 is a setting adjustment mode or a sensing information reading mode based on the signal frequency on the first channel 310 or the voltage level on the power rail 400. The mode control circuit 234 controls the sensing information transmission circuit 210 and the control information slave circuit 220 to transmit or receive signals through the signal transmission interface 300 based on the judgment result of the mode detection circuit 232.

[0017] In embodiments of the present invention, hysteresis control techniques are incorporated for mode switching to ensure that control information transmitted by the master control device 100 is not missed by the sensing device 200. For details of this feature, please refer to further reference. Figure 2 The architecture diagram shown and Figure 3 The timing diagram is shown. First, according to... Figure 2 As shown, the mode detection circuit 232 of the sensing device 200 also includes a stationary detection unit 2321 and a frequency detection unit 2322. Furthermore, according to... Figure 3As shown, before entering the setting adjustment mode or the sensing information reading mode, the main control device 100 requests the mode switching circuit 130 to transmit a DC signal through the first channel 310. This DC signal may have a logic high level or a logic low level. When the stillness detection unit 2321 detects that the signal on the first channel 310 has maintained a DC state for a period of time (state A), it determines that the main control device 100 has entered the setting adjustment mode (state B), and further requests the mode control circuit 234 to perform mode switching, allowing the sensing device 200 to enter the setting adjustment mode and activating the control information slave circuit 220 (state C). Afterwards, the control information master circuit 120 will transmit the control information in the signal format of the second transmission protocol through the first channel 310 and the second channel 320 (state D). After the control information master circuit 120 completes the transmission of the control information, the mode switching circuit 130 will again transmit a DC signal on the first channel 310 (state E). At this time, the frequency detection unit 2322 did not detect that the frequency had reached the predetermined threshold, which caused a hysteresis effect. It determined that the main control device 100 was still in the setting adjustment mode (state F), and therefore allowed the mode control circuit 234 to continue in the setting adjustment mode, continuously activating the control information transmission circuit 220 (state G). Later, when the main control device 100 intended to start reading sensing information, the mode control circuit 234 would cause the sensing information receiving circuit 110 to emit a clock signal conforming to the first transmission protocol on the first channel 310 (state H). At this time, the frequency detection unit 2322 would detect that the signal frequency on the first channel 310 was greater than a frequency threshold TH (e.g., 400 kHz), thereby determining that the main control device 100 had switched to the sensing information reading mode (state I), and further requesting the mode control circuit 234 to activate the sensing information transmission circuit 210 (state J). Subsequently, the sensing information transmission circuit 210 transmits the sensing information generated by the sensing module 240 to the main control device 100 (state K) through the second channel 320 in a format compatible with the second transmission protocol. However, in the sensing information reading mode, if the frequency detection unit 2322 detects that the signal frequency on the first channel 310 is lower than the frequency threshold TH (state L, state M), since the static detection unit 2321 has not detected the DC state on the first channel 310, the mode switching circuit 230 will not immediately cause the mode control circuit 234 to start the control information slave circuit 220 to enter the setting adjustment mode, nor will it end the sensing information reading mode. Instead, it must wait until the static detection unit 2321 detects that the signal on the first channel 310 maintains a DC state before determining that the main control device 100 has entered the setting adjustment mode and causing the mode control circuit 234 to start the control information slave circuit 220. Further details regarding the above mode switching can be found in... Figure 4As shown in the diagram, in the setting adjustment mode, the frequency needs to be increased above the threshold value TH before switching to the sensing information reading mode. However, once the frequency falls below the threshold value TH, it does not immediately switch to the sensing information reading mode, but waits until the frequency is zero (DC state) before switching to the sensing information reading mode.

[0018] Figure 5 The following is a detailed architecture of a master control device simultaneously controlling and accessing multiple sensing devices in an embodiment of the present invention. As shown, the master control device 100 controls and accesses sensing devices 200_1 to 200_3 through a first channel 310, a second channel 320, and a third channel 330. Note that in this embodiment, the number of sensing devices that the master control device 100 can access simultaneously is not limited by the present invention. The master control device 100 mainly includes a master control circuit 150, one or more sensing information receiving circuits 110_1 to 110_3, a control information master circuit 120_1 to 120_3, multiplexers 161 to 169, and logic control circuits 171 to 173. In this embodiment, the control information master circuits 120_1 to 120_3 are essentially I... 2 C main circuit, according to I 2 The C transmission protocol is used to control the sensing devices 200_1 to 200_3. Therefore, multiplexers 161 to 162, 164 to 165, 167 to 168, logic control circuits 171 to 173, and resistors 181 to 186 are designed to comply with I... 2 The C transmission protocol requires that signals on the channel be pulled up or down (due to I...). 2 The C main circuit adopts an open-drain architecture. Accordingly, in other embodiments of the present invention, if the control information main circuits 120_1 to 120_3 are not I 2 In the C main circuit, the aforementioned circuit components can be ignored.

[0019] The main control circuit 150 can determine whether the main control device 100 operates in a setting / adjustment mode or a sensing information reading mode. Specifically, the main control circuit 105 controls the multiplexer 163 to determine which clock signal—generated by the sensing information receiving circuit 110_1 or the control information main circuit 120_1—can be transmitted to the clock channel (i.e., the first channel) 310 via the clock pad 191. In the setting / adjustment mode, the multiplexer 163 causes the clock signal generated by the control information main circuit 120_1 to be transmitted to the clock channel 310 and received by the sensing devices 200_1 to 200_3. Simultaneously, signals generated by the control information main circuits 120_2 and / or 120_3 can be transmitted to the data channels 320 and 330 via data pads 192 and 193. These data signals contain specific control information, such as device ID and control parameters. Once the mode detection circuits 232_1 to 232_3 in the sensing devices 200_1 to 200_3 detect that the signal of the clock channel 310 is in a DC state, they switch the mode to the set adjustment mode and start the control information transmission circuit (i.e., I) 2 The circuits 220_1 to 220_3 receive signals from data channels 320 and 330. Furthermore, the sensing devices 200_1 to 200_3 selectively adjust their setting parameters based on the device ID in the signals. Additionally, the main control circuit 150, through switching multiplexers 166 and 169, allows the control information main circuits 120_2 and / or 120_3 to receive signals from data channels 320 and 330 from data pads 192 and 193, such as parameter setting results returned by the sensing devices 200_1 to 200_3.

[0020] On the other hand, in the sensing information reading mode, the multiplexer 163 transmits the clock signal generated by the sensing information receiving circuit 110_1 to the clock channel 310 via the clock pad 191, and it is received by the sensing devices 200_1 to 200_3. The mode detection circuits 232_1 to 232_3 in the sensing devices 200_1 to 200_3 detect that the signal frequency of the clock channel 310 is greater than the threshold value TH, thereby switching the mode to the sensing information reading mode and activating the sensing information transmission circuits 210_1 to 210_3. The sensing information transmission circuits 210_1 to 210_3 transmit the sensing information generated by the sensing devices 200_1 to 200_3 back to the main control device 100 via the data channels 320 and 330. At this time, through the switching of multiplexers 166 and 169, the sensing information receiving circuits 110_2 and / or 110_3 can receive signals from data channels 320 and 330 via data pads 192 and 193, thereby obtaining the sensing information returned by sensing devices 200_1 to 200_3. Note that although in this embodiment, the main control device 100 includes sensing information receiving circuits 110_1 to 110_3 and control information main circuits 120_1 to 120_3, in other embodiments of the present invention, some of the sensing information receiving circuits or control information main circuits can be integrated into one. For example, control information main circuits 120_1 to 120_3 can be integrated into one, while sensing information receiving circuits 110_1 to 110_3 can also be integrated into two.

[0021] Furthermore, although in the above embodiments, the mode detection circuit 232 and mode control circuit 234 in the sensing device 200 perform mode detection and switching based on the signal frequency on the clock channel 310, in other embodiments of the present invention, the mode detection circuit 232 and mode control circuit 234 in the sensing device 200 may also perform mode detection and switching based on the voltage level of the power rail 400. For example, the mode switching circuit 130 in the master control device 100 may increase the voltage level of the power rail 400 to 2.7V when the master control circuit 150 decides to transmit control information, and decrease the voltage level of the power rail 400 to 1.8V when deciding to receive sensing information. Accordingly, the mode detection circuit 232 and mode control circuit 234 in the sensing device 200 can determine when to sense the information transmission circuit 210 or activate the control information slave circuit 220 based on the voltage level of the power rail 400.

[0022] In summary, this invention provides a signal transmission architecture that integrates sensing information transmission and control information transmission, enabling a single signal transmission interface to support signals from multiple transmission protocols. Examples include the aforementioned PDM-based transmission protocol for transmitting sensing information, and the I / O protocol for transmitting control information. 2The present invention can control and read sensing information from a sensing device without significantly increasing hardware costs and circuit complexity, thereby enabling the setting / characteristic adjustment of the sensing device. This can be achieved using protocols such as C, SPI, UART, or 1-wire.

[0023] The above description is only a preferred embodiment of the present invention. All equivalent changes and modifications made in accordance with the claims of the present invention shall be covered by the present invention.

[0024] [Symbol Explanation]

[0025] 100 Main control device

[0026] 110, 110_1~110_3 Sensing Information Receiving Circuit

[0027] 120, 120_1~110_3 Control Information Main Circuit

[0028] 130 Mode Switching Circuit

[0029] 150 Main control circuit

[0030] 161-169 Multiplexers

[0031] Logic control circuits 171-173

[0032] 181-186 resistors

[0033] 191 Clock Connector

[0034] Data pads 192 and 193

[0035] 200, 200_1~200_3 sensing devices

[0036] 210, 210_1~210_3 Sensing Information Transmission Circuit

[0037] 220, 220_1~220_3 control information from circuit

[0038] 230 Mode Switching Circuit

[0039] 232 mode detection circuit

[0040] 2321 Static Detection Unit

[0041] 2322 Frequency Detection Unit

[0042] 234 Mode Control Circuit

[0043] 240 sensing module

[0044] 300 signal transmission interface

[0045] 310 Clock Channel

[0046] 320, 330 data channels

[0047] 400 power rail.

Claims

1. A sensing device, comprising: A sensing information transmission circuit is used to convert sensing information into a transmission signal conforming to a signal format of a first transmission protocol according to a first transmission protocol. A control information slave circuit is used to convert a received signal from a signal transmission interface into control information according to a second transmission protocol, thereby setting the sensing device; and A mode switching circuit, coupled to the sensing information transmission circuit and the control information slave circuit, is used to activate one of the sensing information transmission circuit and the control information slave circuit based on a signal on a clock channel, a signal on a data channel, or a signal on a power rail of the sensing device on the signal transmission interface, so that the sensing information transmission circuit or the control information slave circuit can transmit or receive signals through the signal transmission interface. in, The first transmission protocol is a pulse density modulation-based transmission protocol, and the second transmission protocol is an I²C protocol, a sequence peripheral interface protocol, a general asynchronous transceiver protocol, or a single-wire protocol.

2. The sensing device according to claim 1, wherein the sensing device is a digital microelectromechanical microphone, a vibration sensor, a pressure sensor, an optical sensor or a temperature sensor, and the sensing information is audio information, vibration information, pressure information, optical information or temperature information.

3. The sensing device according to claim 1, wherein the mode switching circuit comprises: A mode detection circuit, coupled to the clock channel or the power rail, is used to generate a detection result based on the signal on the clock channel or the signal on the power rail; and A mode control circuit is coupled to the sensing information transmission circuit, the control information slave circuit, and the mode detection circuit, for activating one of the sensing information transmission circuit and the control information slave circuit based on the detection result.

4. The sensing device according to claim 3, wherein the mode switching circuit activates the sensing information transmission circuit when the detection result indicates that the frequency of the signal on the clock channel is higher than a first threshold, the signal on the data channel corresponds to a signal feature, or the voltage level of the signal on the power rail is lower than a second threshold; and the mode switching circuit activates the control information slave circuit when the detection result indicates that the frequency of the signal on the clock channel is lower than the first threshold or the voltage level of the signal on the power rail is higher than the second threshold.

5. The sensing device according to claim 4, wherein when the sensing information transmission circuit is activated, the mode switching circuit will only activate the control information slave circuit when the signal on the clock channel remains in a continuous state.

6. The sensing device according to claim 3, wherein the detection result indicates whether the frequency of the signal on the clock channel is higher or lower than a first threshold, whether the decoded content of the signal on the data channel conforms to a signal characteristic, or whether the voltage level of the signal on the power rail is higher or lower than a second threshold, and the mode switching circuit determines whether to activate the sensing information transmission circuit or the control information slave circuit based on the detection result.

7. A master control device, comprising: A sensing information receiving circuit is used to convert a received signal received from a signal transmission interface into sensing information according to a first transmission protocol. A control information main circuit is used to convert control information into a transmission signal conforming to a signal format of a second transmission protocol; and A mode switching circuit, coupled to the sensing information receiving circuit and the control information main circuit, is used to adjust the signal on a clock channel, a data channel, or a power rail of a sensing device on the signal transmission interface according to an operating mode of the main control device, thereby controlling one of the sensing information receiving circuit or the control information main circuit to use the signal transmission interface for signal reception or transmission. in, The first transmission protocol is a pulse density modulation-based transmission protocol, and the second transmission protocol is an I²C protocol, a sequence peripheral interface protocol, a general asynchronous transceiver protocol, or a single-wire protocol.

8. The main control device according to claim 7, wherein the sensing device is a digital microelectromechanical microphone, a vibration sensor, a pressure sensor, an optical sensor or a temperature sensor, and the sensing information is audio information, vibration information, pressure information, optical information or temperature information.

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