Temperature and humidity conversion unibus circuit

Abstract

The utility model relates to the technical field of temperature and humidity monitoring, and discloses a temperature and humidity conversion unibus circuit, which comprises a temperature and humidity sensor chip U1, a 1-Wire bus interface chip U2, a 100nF filter capacitor C1, a 2uF filter capacitor C2 and a Schottky diode D1, the IO pin 1 of the 1-Wire bus interface chip U2 is connected with a DQ line, the DQ line is a data signal line connected with a bus, and the IO pin 2 of the 1-Wire bus interface chip U2 is connected with the Schottky diode D1. And the anode of the Schottky diode D1 is connected with a DQ line, the cathode of the Schottky diode D1 is connected with VDD, and the Schottky diode D1 is used for providing reverse voltage protection for a pin IO of the 1-Wire bus interface chip U2. According to the technical scheme of the utility model, DS28EA00U + Tamp is adopted. The R1-Wire bus interface chip U2 and the IC bus of the SHT30-DIS-B temperature and humidity sensor chip U1 are multiplexed, a set of communication line does not need to be independently arranged for each chip, and the design of a power supply loop is simplified.

Description

Technical Field

[0001] This utility model relates to the field of temperature and humidity monitoring technology, and in particular to a temperature and humidity conversion single-bus circuit. Background Technology

[0002] In embedded systems, the Internet of Things (IoT), and environmental monitoring, the acquisition and transmission of temperature and humidity parameters are core requirements. Single-wire technology achieves data transmission and power supply through a single signal line. Single-wire circuits can significantly reduce costs by decreasing the number of components (e.g., eliminating the need for a separate clock line and simplifying interface circuitry) and lowering wiring complexity. Therefore, a single-wire temperature and humidity conversion circuit is needed.

[0003] A single-bus circuit for temperature and humidity conversion can collect environmental temperature and humidity data in real time and transmit the data via a single bus. The standardized design of the single-bus circuit can be adapted to different scenarios through a unified interface, reducing cross-scenario development costs. However, in previous technologies, there was a lack of design for multiplexing the I²C bus between two chips, requiring the design of independent communication lines. This resulted in additional occupation of the main controller's communication interface resources, reduced communication efficiency, and the need for more wiring space, increasing PCB board area and wiring complexity. Utility Model Content

[0004] To overcome the above shortcomings, this utility model provides a temperature and humidity conversion single-bus circuit, which aims to improve the existing technology's lack of two-chip I²C bus multiplexing design, which requires the design of independent communication lines, resulting in additional occupation of the main controller's communication interface resources, reduced communication efficiency, and the need for more wiring space, which increases the PCB board area and wiring complexity.

[0005] To achieve the above objectives, this utility model provides the following technical solution: a temperature and humidity conversion single-bus circuit, including a temperature and humidity sensor chip U1, a 1-Wire bus interface chip U2, a 100nF filter capacitor C1, a 2uF filter capacitor C2, and a Schottky diode D1. The IO pin 1 of the 1-Wire bus interface chip U2 is connected to a DQ line, which is a data signal line for connecting the bus and used for single-bus data transmission and reception. The anode of the Schottky diode D1 is connected to the DQ line, and the cathode is connected to VDD, which is used to provide reverse voltage protection for the IO pin of the 1-Wire bus interface chip U2. The SDA pin 1 of the temperature and humidity sensor chip U1 is connected to the PIOA pin 6 of the 1-Wire bus interface chip U2. The SCL pin 4 of the temperature and humidity sensor chip U1 is connected to the PIOB pin 7 of the 1-Wire bus interface chip U2. The 1-Wire bus interface chip U2 and the temperature and humidity sensor chip U1 share the same I²C bus.

[0006] The above technical solution constructs an I²C bus shared by the SHT30-DIS-B temperature and humidity sensor chip U1 and the DS28EA00U+T&R1-Wire bus interface chip U2. This simplifies circuit design, ensures the flexibility and reliability of data interaction, and enables the system to efficiently complete functions such as temperature and humidity acquisition, parameter storage, and collaborative calibration within a compact space. It also enables communication between multiple devices without the need to design separate communication lines for chips U1 and U2. This reuse method can significantly reduce the number of wires on the PCB board, thereby reducing circuit size and hardware costs.

[0007] Preferably, the temperature and humidity sensor chip U1 is model SHT30-DIS-B, the 1-Wire bus interface chip U2 is model DS28EA00U+T&R, SDA is the data line, SCL is the clock line, and the two together constitute a standard I²C bus.

[0008] Preferably, the 100nF filter capacitor C1 is connected in parallel between the VDD and GND terminals of the SHT30-DIS-B temperature and humidity sensor chip U1 for high-frequency filtering, and the 2uF filter capacitor C2 is connected in parallel between the VDD and GND terminals of the DS28EA00U+T&R1-Wire bus interface chip U2 for low-frequency filtering.

[0009] Preferably, the SDA pin 1 of the SHT30-DIS-B temperature and humidity sensor chip U1 is connected to a pull-up resistor R1, and the other end of the pull-up resistor R1 is connected to VDD.

[0010] Preferably, the SCL pin 4 of the SHT30-DIS-B temperature and humidity sensor chip U1 is connected to a pull-up resistor R2, and the other end of the pull-up resistor R2 is connected to VDD.

[0011] Preferably, pin 8 of the DS28EA00U+T&R1-Wire bus interface chip U2 is connected to the positive power supply to power the chip, and pin 5 of the SHT30-DIS-B temperature and humidity sensor chip U1 is connected to the positive power supply to power the chip.

[0012] Preferably, pin 2 of the SHT30-DIS-B temperature and humidity sensor chip U1 is directly grounded, and pins 7, 8, and 9 of the SHT30-DIS-B temperature and humidity sensor chip U1 are all grounded.

[0013] Preferably, pins 3 and 6 of the SHT30-DIS-B temperature and humidity sensor chip U1 are directly left floating, and pins 2, 3, and 5 of the DS28EA00U+T&R1-Wire bus interface chip U2 are directly left floating.

[0014] This utility model has the following beneficial effects:

[0015] 1. In this utility model, by multiplexing the I²C bus of the DS28EA00U+T&R1-Wire bus interface chip U2 and the SHT30-DIS-B temperature and humidity sensor chip U1, the main controller can manage and interact with multiple devices under a unified communication architecture. There is no need to set up a separate communication line for each chip, which simplifies the power supply circuit design, saves the pin resources of the main control chip and the wiring space of the circuit board, and meets the monitoring needs of multiple scenarios.

[0016] 2. In this utility model, the 100nF high-frequency filter capacitor and the 2.2μF low-frequency filter capacitor can effectively suppress power supply noise and ripple, providing a stable power supply environment for the sensor. By combining the SHT30-DIS-B temperature and humidity sensor chip U1 and the DS28EA00U+T&R1-Wire bus interface chip U2, the effects of high-precision temperature and humidity acquisition, reliable data storage and flexible communication expansion are achieved, improving the accuracy and consistency of temperature and humidity measurement. Attached Figure Description

[0017] Figure 1 This is a schematic diagram of the circuit principle of a single-bus circuit for temperature and humidity conversion proposed in this utility model. Detailed Implementation

[0018] The technical solutions of the embodiments of this utility model will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some embodiments of this utility model, and not all embodiments. Based on the embodiments of this utility model, all other embodiments obtained by those skilled in the art without creative effort are within the protection scope of this utility model.

[0019] Reference Figure 1This utility model provides an embodiment of a temperature and humidity conversion single-bus circuit, including a temperature and humidity sensor chip U1, a 1-Wire bus interface chip U2, a 100nF filter capacitor C1, a 2uF filter capacitor C2, and a Schottky diode D1. The IO pin 1 of the 1-Wire bus interface chip U2 is connected to a DQ line, which is a data signal line for connecting to the bus and used for single-bus data transmission and reception. The anode of the Schottky diode D1 is connected to the DQ line, and the cathode is connected to VDD, providing reverse voltage protection for the IO pin of the 1-Wire bus interface chip U2. Pin 1 of SDA of chip U1 is connected to pin 6 of PIOA of 1-Wire bus interface chip U2, and pin 4 of SCL of temperature and humidity sensor chip U1 is connected to pin 7 of PIOB of 1-Wire bus interface chip U2. 1-Wire bus interface chip U2 and temperature and humidity sensor chip U1 share the same I²C bus. Temperature and humidity sensor chip U1 is model SHT30-DIS-B, and 1-Wire bus interface chip U2 is model DS28EA00U+T&R. SDA is the data line, and SCL is the clock line. Together, they form a standard I²C bus.

[0020] Specifically, the DS28EA00U+T&R is a single-bus digital temperature sensor capable of accurately measuring ambient temperature. It also features EEPROM storage to meet users' data storage needs, eliminating the need for additional dedicated storage chips. This simplifies circuit design, reduces costs, and minimizes board area. Pull-up resistors R1 and R2 provide pull-up resistors for the SDA data line and SCL clock line of the SHT30-DIS-B temperature and humidity sensor chip U1, ensuring signal stability. Furthermore, the pull-up resistors R1 and R2 are connected to V... The DD power supply forms a standard I²C bus, which is then multiplexed with the PIOA and PIOB pins of the DS28EA00U+T&R1-Wire bus interface chip U2 to form a shared I²C bus. This enables I²C communication between the two chips and the main controller. When an abnormally high voltage occurs on the 1-Wire bus, the Schottky diode D1 conducts in reverse to clamp the voltage within a certain range, preventing excessive voltage from damaging the IO pins of the DS28EA00U+T&R1-Wire bus interface chip U2.

[0021] Reference Figure 1A 100nF filter capacitor C1 is connected in parallel between the VDD and GND terminals of the SHT30-DIS-B temperature and humidity sensor chip U1 for high-frequency filtering; a 2uF filter capacitor C2 is connected in parallel between the VDD and GND terminals of the DS28EA00U+T&R1-Wire bus interface chip U2 for low-frequency filtering; a pull-up resistor R1 is connected to pin 1 of the SHT30-DIS-B temperature and humidity sensor chip U1, and the other end of the pull-up resistor R1 is connected to VDD; a pull-up resistor R2 is connected to pin 4 of the SHT30-DIS-B temperature and humidity sensor chip U1, and the other end of the pull-up resistor R2 is connected to VDD.

[0022] Specifically, a 100nF filter capacitor C1 and a 2uF filter capacitor C2 are connected in parallel between the power supply and ground terminals of the SHT30-DIS-B temperature and humidity sensor chip U1 and the DS28EA00U+T&R1-Wire bus interface chip U2, respectively. This serves to filter the power supply of the two chips, eliminating noise at different frequency bands, stabilizing the power supply voltage, and ensuring that the sensor chips operate in a stable power environment. This reduces the impact of noise on measurement accuracy and communication reliability. The 100nF filter capacitor C1 filters out high-frequency noise and ripple in the power supply, preventing these interferences from affecting the chip's operation and ensuring that the internal circuitry of the chip operates in a stable power environment for temperature and humidity measurement. The accurate acquisition and processing of temperature and humidity data filters out noise in the chip's power supply circuit and stabilizes the power supply voltage. The 2uF filter capacitor C2 mainly filters out low-frequency noise and stabilizes power supply voltage fluctuations. However, in the actual circuit working environment, there are various interference sources, such as electromagnetic interference and power supply noise. Pull-up resistors R1 and R2 can pull the SDA and SCL pins of the SHT30-DIS-B temperature and humidity sensor chip U1 high to VDD, respectively. This ensures that the I²C bus has a stable high-level reference in the idle state, which can effectively suppress the influence of interference signals on the bus level, reduce misjudgments caused by noise, and thus improve the stability and anti-interference capability of I²C bus communication.

[0023] Reference Figure 1 Pin 8 of the DS28EA00U+T&R1-Wire bus interface chip U2 is connected to the positive power supply to power the chip internally. Pin 5 of the SHT30-DIS-B temperature and humidity sensor chip U1 is also connected to the positive power supply to power the chip internally. Pin 2 of the SHT30-DIS-B temperature and humidity sensor chip U1 is directly grounded. Pins 7, 8, and 9 of the SHT30-DIS-B temperature and humidity sensor chip U1 are all grounded. Pins 3 and 6 of the SHT30-DIS-B temperature and humidity sensor chip U1 are left floating. Pins 2, 3, and 5 of the DS28EA00U+T&R1-Wire bus interface chip U2 are also left floating.

[0024] Specifically, connecting pin 8 of the DS28EA00U+T&R1-Wire bus interface chip U2 to the positive power supply provides the chip with operating voltage, ensuring that the chip can perform core functions such as temperature measurement, data transmission, and storage read / write. Similarly, connecting pin 5 of the SHT30-DIS-B temperature and humidity sensor chip U1 to the positive power supply also provides operating voltage, powering the temperature and humidity sensor's measurement circuit and I²C communication module, ensuring that it can normally collect and transmit temperature and humidity data. Grounding pins 7, 8, and 9 of chip U1 unifies the circuit potential reference, ensuring stable signal levels, forming a complete power supply loop, and also helps with chip heat dissipation and electrical performance stability. Directly grounding pin 2 of chip U1 determines the UI chip's address on the I²C bus, avoiding bus conflicts and ensuring normal communication. Leaving unnecessary pins floating simplifies circuit design.

[0025] Working Principle: In use, the DS28EA00U+T&R1-Wire bus interface chip U2 can first be connected to the 1-Wire network via the D and G terminals. This allows the main controller to remotely read and write chip data and control functions via a single bus. The IO pins of chip U2 are connected to the external network via the DQ line for data input and output. Simultaneously, a Schottky diode D1 acts as a clamping protection to prevent damage to the chip from reverse voltage generated by external circuits, ensuring the chip's safety during data exchange. Furthermore, the SHT30-DIS-B temperature and humidity sensor chip U1 is connected to the same I²C bus via the SDA and SCL pins, and the DS28EA00U+T&R1-Wire bus interface chip U2 is connected via the PIOA and PIOB pins. This allows the main controller to communicate with both chips via this I²C bus, enabling the reading of temperature and humidity data and control of related chip functions. A 100nF filter capacitor C1 is connected in parallel between the power input terminal and ground terminal of chip U1. The high-frequency noise generated during chip operation is efficiently absorbed to provide power filtering for its internal circuitry, ensuring stable power supply and thus guaranteeing the accuracy of temperature and humidity measurement and the stability of chip operation. A 2.2uF filter capacitor C2 is connected in parallel between the power input terminal VDD pin 8 and the ground terminal GND pin 4 of chip U2 to provide a stable power supply for the chip and filter the power supply to reduce the impact of power supply noise on chip operation, ensuring normal operation of the chip. The SDA pin 1 and SCL pin 4 of SHT30-DIS-B temperature and humidity sensor chip U1 are connected to the power supply VDD through pull-up resistors R1 and R2, respectively, thus forming an I²C communication bus. This allows SHT30-DIS-B temperature and humidity sensor chip U1 to transmit data with the main control unit on the circuit board, sending the measured temperature and humidity data to the main control unit, ensuring the stability and reliability of communication. Furthermore, the pull-up resistors R1 and R2 ensure that the SDA data line and SCL clock line are in a high-level state when there is no data transmission, thus ensuring the stability and reliability of communication.

[0026] Through the above connection, the SHT30-DIS-B temperature and humidity sensor chip U1 can accurately measure the ambient temperature and humidity, while the DS28EA00U+T&R1-Wire bus interface chip U2 can provide auxiliary functions and data storage support. By utilizing the I²C and 1-Wire dual buses to achieve flexible communication, the system ultimately achieves the functions of coordinated acquisition of temperature and humidity, data storage, and system expansion, as well as multi-dimensional environmental monitoring and efficient data interaction.

[0027] Finally, it should be noted that the above description is only a preferred embodiment of the present utility model and is not intended to limit the present utility model. Although the present utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art can still modify the technical solutions described in the foregoing embodiments or make equivalent substitutions for some of the technical features. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principles of the present utility model should be included within the protection scope of the present utility model.

Claims

1. A temperature and humidity conversion single-bus circuit, comprising a temperature and humidity sensor chip U1, a 1-Wire bus interface chip U2, a 100nF filter capacitor C1, a 2uF filter capacitor C2, and a Schottky diode D1, characterized in that: The IO pin 1 of the 1-Wire bus interface chip U2 is connected to the DQ line, which is a data signal line for connecting the bus and used for single-bus data transmission and reception. The anode of the Schottky diode D1 is connected to the DQ line, and the cathode is connected to VDD, which is used to provide reverse voltage protection for the IO pin of the 1-Wire bus interface chip U2. The SDA pin 1 of the temperature and humidity sensor chip U1 is connected to the PIOA pin 6 of the 1-Wire bus interface chip U2. The SCL pin 4 of the temperature and humidity sensor chip U1 is connected to the PIOB pin 7 of the 1-Wire bus interface chip U2. The 1-Wire bus interface chip U2 and the temperature and humidity sensor chip U1 share the same I²C bus.

2. The temperature and humidity conversion single-bus circuit according to claim 1, characterized in that: The temperature and humidity sensor chip U1 is model SHT30-DIS-B, the 1-Wire bus interface chip U2 is model DS28EA00U+T&R, SDA is the data line, SCL is the clock line, and the two together constitute a standard I²C bus.

3. The temperature and humidity conversion single-bus circuit according to claim 1, characterized in that: The 100nF filter capacitor C1 is connected in parallel between the VDD and GND terminals of the SHT30-DIS-B temperature and humidity sensor chip U1 for high-frequency filtering, and the 2uF filter capacitor C2 is connected in parallel between the VDD and GND terminals of the DS28EA00U+T&R1-Wire bus interface chip U2 for low-frequency filtering.

4. The temperature and humidity conversion single-bus circuit according to claim 2, characterized in that: The SDA pin 1 of the SHT30-DIS-B temperature and humidity sensor chip U1 is connected to a pull-up resistor R1, and the other end of the pull-up resistor R1 is connected to VDD.

5. A temperature and humidity conversion single-bus circuit according to claim 2, characterized in that: The SCL pin 4 of the SHT30-DIS-B temperature and humidity sensor chip U1 is connected to a pull-up resistor R2, and the other end of the pull-up resistor R2 is connected to VDD.

6. The temperature and humidity conversion single-bus circuit according to claim 3, characterized in that: Pin 8 of the DS28EA00U+T&R1-Wire bus interface chip U2 is connected to the positive power supply to power the chip internally, and pin 5 of the SHT30-DIS-B temperature and humidity sensor chip U1 is connected to the positive power supply to power the chip internally.

7. A temperature and humidity conversion single-bus circuit according to claim 2, characterized in that: Pin 2 of the SHT30-DIS-B temperature and humidity sensor chip U1 is directly grounded, and pins 7, 8, and 9 of the SHT30-DIS-B temperature and humidity sensor chip U1 are all grounded.

8. A temperature and humidity conversion single-bus circuit according to claim 3, characterized in that: Pins 3 and 6 of the SHT30-DIS-B temperature and humidity sensor chip U1 are directly left floating, and pins 2, 3, and 5 of the DS28EA00U+T&R1-Wire bus interface chip U2 are also directly left floating.

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