Temperature and humidity detection circuit

Abstract

The utility model discloses a temperature and humidity detection circuit, and relates to the field of detection circuits. According to the specific implementation scheme, the system comprises an infrared transmitting and receiving module, a temperature and humidity detection module, a main control module for controlling the infrared transmitting and receiving module and the temperature and humidity detection module, and a power supply module for supplying power to the infrared transmitting and receiving module, the temperature and humidity detection module and the main control module; the infrared transmitting and receiving module is electrically connected with the main control module, the temperature and humidity detection module is electrically connected with the main control module, and the infrared transmitting and receiving module, the temperature and humidity detection module and the main control module are all electrically connected with the power supply module. The infrared transmitting and receiving module, the temperature and humidity detection module, the master control module for controlling transmitting and receiving of infrared signals and the power supply module are installed on the PCB, the whole space is small and exquisite, the device can go deep into a precise small-space structural member, and temperature and humidity data in the structural member can be detected by arranging the temperature and humidity detection module.

Description

Technical Field

[0001] The utility model relates to the field of detection circuits, in particular to a temperature and humidity detection circuit. Background Art

[0002] Currently, many electronic products must pass certain levels of waterproofing testing before leaving the factory. Even though structural components are waterproofed with seals and glued edges, moisture and water can still enter. Conventional structural components lack the ability to monitor internal temperature and humidity. Consequently, even if internal moisture causes electronic modules to malfunction, it's impossible to determine whether the cause is a structural waterproofing defect or a hardware issue within the electronic module itself. Utility Model Content

[0003] Based on this, the utility model provides a temperature and humidity detection circuit to solve the problem that the existing technology cannot collect humidity data inside structural parts.

[0004] The utility model provides a temperature and humidity detection circuit, comprising:

[0005] Infrared transmitting and receiving module, temperature and humidity detection module, a main control module for controlling the infrared transmitting and receiving module and the temperature and humidity detection module, and a power supply module for providing power to the infrared transmitting and receiving module, the temperature and humidity detection module and the main control module;

[0006] The infrared transmitting and receiving module is electrically connected to the main control module, the temperature and humidity detection module is electrically connected to the main control module, and the infrared transmitting and receiving module, the temperature and humidity detection module and the main control module are all electrically connected to the power module.

[0007] The main control module includes a main control chip U01, wherein pin 1 of the main control chip U01 is connected to pin 2 of the SWD download plug-in J1 through a third pull-up resistor R03, pin 2 of the main control chip U01 is connected to pin 1 of the SWD download plug-in J1, pin 32 of the main control chip U01 is connected to pin 3 of the SWD download plug-in J1 through a fourth pull-up resistor R04, pin 29 of the main control chip U01 is connected to pin 4 of the SWD download plug-in J1, and pin 28 of the main control chip U01 is connected to pin 1 of the SWD download plug-in J1 through a fourth pull-up resistor R05. The first capacitor C01 is connected to pin 5 of the SWD download plug-in J1, the second capacitor C02 is used to connect pin 5 of the SWD download plug-in J1, the second capacitor C02 is used to connect pin 26 of the main control chip U01 to pin 5 of the SWD download plug-in J1 through the third capacitor C03, the signal receiving port BOOT-RX of the BOOT interface of the main control chip U01, and the signal sending port BOOT-TX of the BOOT interface of the main control chip U01 is BOOT-10.

[0008] The temperature and humidity detection module includes a temperature and humidity detection chip U1, a first pull-up resistor R1, and a second pull-up resistor R2. Pin 1 of the temperature and humidity detection chip U1 is connected to pin 13 of the main control chip U01 through the first pull-up resistor R1, pin 6 of the temperature and humidity detection chip U1 is connected to pin 14 of the main control chip U01 through the second pull-up resistor R2, pin 2 of the temperature and humidity detection chip U1 is grounded, and pin 5 of the temperature and humidity detection chip U1 is connected to VCC.

[0009] The temperature and humidity detection module also includes a first transistor Q41, a third current limiting resistor R41, a fourth current limiting resistor R42 and a temperature and humidity over-limit alarm indicator D41;

[0010] The collector of the first transistor Q41 is connected to one end of the temperature and humidity over-limit alarm indicator light D41, and the other end of the temperature and humidity over-limit alarm indicator light D41 is connected to VCC through the third current limiting resistor R41. The base of the first transistor Q41 is connected to pin 21 of the main control chip U01 through the fourth current limiting resistor R42, and the emitter of the first transistor Q41 is grounded.

[0011] The infrared transmitting and receiving module includes a transmitting circuit and a receiving circuit.

[0012] The transmitting circuit includes a PNP transistor Q31, a first current limiting resistor R31, a bias resistor R32, a second current limiting resistor R33 and an infrared signal transmitting tube D31. The collector of the PNP transistor Q31 is connected to VCC, the bias resistor R32 is connected between the collector and the base of the PNP transistor Q31, the base of the PNP transistor Q31 is connected to pin 18 of the main control chip U01 through the first current limiting resistor R31, the emitter of the PNP transistor Q31 is connected to one end of the infrared signal transmitting tube D31, and the other end of the infrared signal transmitting tube D31 is grounded through the second current limiting resistor R33.

[0013] The receiving circuit includes an NPN transistor Q32, an infrared signal receiving tube D32, a blue light indicator D33, a fifth current limiting resistor R37, a voltage dividing resistor R36 and a normal pull-up resistor R38;

[0014] The base of the NPN transistor Q32 is connected to pin 5 of the main control chip U01 through the infrared signal receiving tube D32, and the base of the NPN transistor Q32 is also grounded through the voltage divider resistor R36. The emitter of the NPN transistor Q32 is grounded, one end of the blue light indicator D33 is connected to pin 5 of the main control chip U01, and the other end of the blue light indicator D33 is connected to the collector of the NPN transistor Q32 through the fifth current limiting resistor R37. One end of the normal pull-up resistor R38 is connected to the collector of the NPN transistor Q32, and the other end of the normal pull-up resistor R38 is connected to pin 5 of the main control chip U01.

[0015] The power module includes an LDO chip U11, a battery line interface DB1, and a Schottky diode D1. Pin 1 of the LDO chip U11 is grounded, pin 2 of the LDO chip U11 is connected to pin 1 of the battery line interface DB1 through the Schottky diode D1, pin 3 of the LDO chip U11 is connected to VCC, pin 1 of the battery line interface DB1 is also connected to VBAT, and the battery line interface DB1 is grounded.

[0016] Beneficial effect: The utility model installs the infrared transmitting and receiving module, the temperature and humidity detection module, the main control module for controlling the emission and reception of infrared signals, and the power supply module on the PCB board. The overall space is small and can penetrate deep into the interior of precision small-space structural parts. By setting up the temperature and humidity detection module, the temperature and humidity data inside the structural parts can be detected.

[0017] It should be understood that the content described in this section is not intended to identify the key or important features of the embodiments of the present invention, nor is it intended to limit the scope of the present invention. Other features of the present invention will become easily understood through the following description. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The accompanying drawings are used to better understand the present invention and do not constitute a limitation of the present invention.

[0019] Figure 1 This is a circuit diagram of the main control module provided by the utility model;

[0020] Figure 2 This is a circuit diagram of the BOOT interface and SWD download port provided by the utility model;

[0021] Figure 3 This is a circuit diagram of a temperature and humidity detection module provided by the utility model;

[0022] Figure 4 This is a temperature and humidity over-limit alarm circuit diagram provided by the utility model;

[0023] Figure 5 The transmitting circuit diagram provided by the utility model is

[0024] Figure 6 This is a receiving circuit diagram provided by the utility model;

[0025] Figure 7 This is a circuit diagram of a power module provided by the utility model. DETAILED DESCRIPTION

[0026] The following description of exemplary embodiments of the present invention is made in conjunction with the accompanying drawings, which include various details of the embodiments of the present invention to facilitate understanding. These details should be considered as merely exemplary. Therefore, those skilled in the art will recognize that various changes and modifications may be made to the embodiments described herein without departing from the scope and spirit of the present invention. Similarly, for the sake of clarity and conciseness, descriptions of well-known functions and structures are omitted in the following description.

[0027] The utility model provides a temperature and humidity detection circuit, comprising:

[0028] Infrared transmitting and receiving module, temperature and humidity detection module, a main control module for controlling the infrared transmitting and receiving module and the temperature and humidity detection module, and a power supply module for providing power to the infrared transmitting and receiving module, the temperature and humidity detection module and the main control module;

[0029] The infrared transmitting and receiving module is electrically connected to the main control module, the temperature and humidity detection module is electrically connected to the main control module, and the infrared transmitting and receiving module, the temperature and humidity detection module and the main control module are all electrically connected to the power module.

[0030] The infrared transmitting and receiving module, temperature and humidity detection module, main control module for controlling the transmission and reception of infrared signals, and power module are installed on the PCB board. The overall space is small and can penetrate deep into the interior of precision small-space structural parts.

[0031] The utility model uses a lithium battery to provide power for the detection module. The main control module cooperates with the infrared transmitting and receiving modules as the main communication channel. The temperature or humidity is judged according to the detection data of the temperature and humidity detection module. If the temperature or humidity is low and within the normal acceptable range, the LED indicator light will not light up. If the internal temperature or humidity gradually increases until it reaches a certain set threshold, the LED_WORK pin of the main control module is controlled to output a high level and then light up the temperature and humidity over-limit alarm indicator light for interaction.

[0032] like Figure 1 、 2As shown, the main control module includes a main control chip U01, pin 1 of the main control chip U01 is connected to pin 2 of the SWD download plug-in J1 through a third pull-up resistor R03, pin 2 of the main control chip U01 is connected to pin 1 of the SWD download plug-in J1, pin 32 of the main control chip U01 is connected to pin 3 of the SWD download plug-in J1 through a fourth pull-up resistor R04, pin 29 of the main control chip U01 is connected to pin 4 of the SWD download plug-in J1, and pin 28 of the main control chip U01 is connected to pin 1 of the SWD download plug-in J1. The pin is connected to pin 5 of the SWD download plug-in J1 through the first capacitor C01, pin 28 of the main control chip U01 is also connected to pin 5 of the SWD download plug-in J1 through the second capacitor C02, pin 26 of the main control chip U01 is connected to pin 5 of the SWD download plug-in J1 through the third capacitor C03, pin 9 of the main control chip U01 is the signal receiving port BOOT-RX of the BOOT interface, and pin 10 of the main chip U01 is the signal sending port BOOT-TX of the BOOT interface.

[0033] Among them, the first capacitor C01 and the third capacitor C03 are filter capacitors of the main control chip U01, which filter the current sent by the battery power supply to ensure that the power supply voltage of the main control chip U01 is cleaner and within a stable and safe threshold; the second capacitor C02 is an external capacitor of pin 26 of the main control chip U01. The model of the main control chip U01 is FM33LC0x3N, which is a low-power, IO resource-rich microcontroller; the BOOT interface can realize program download in serial port mode, and can also download programs through the SWD download port.

[0034] When used with the serial tool BOOT interface and SWD download port, the host computer can set the module sampling interval, system time, query historical temperature and humidity values, etc. It can also pause and continue collection midway, making it more flexible to use.

[0035] When downloading the program, the signal is valid at a low level. Adding the third pull-up resistor R03 and the fourth pull-up resistor R04 can effectively clamp the level at a high level when not transmitting or downloading data. The overall chip has FLASH, internal clock and reset functions, and does not require an external reset circuit and Flash chip, which is conducive to a smaller overall PCB space.

[0036] like Figure 3As shown, the temperature and humidity detection module includes a temperature and humidity detection chip U1, a first pull-up resistor R1, and a second pull-up resistor R2. Pin 1 of the temperature and humidity detection chip U1 is connected to pin 13 of the main control chip U01 through the first pull-up resistor R1, pin 6 of the temperature and humidity detection chip U1 is connected to pin 14 of the main control chip U01 through the second pull-up resistor R2, pin 2 of the temperature and humidity detection chip U1 is grounded, and pin 5 of the temperature and humidity detection chip U1 is connected to VCC.

[0037] The model of the temperature and humidity detection chip U1 is HDC1080DMBR. The temperature and humidity detection module also includes a first filter capacitor C1 and a second filter capacitor C2. The first filter capacitor C1 and the second filter capacitor C2 are connected to VCC to filter the current sent by the battery power supply to ensure the stability of the power supply voltage of the temperature and humidity detection chip U1.

[0038] The temperature and humidity detection module also includes a first transistor Q41, a third current limiting resistor R41, a fourth current limiting resistor R42 and a temperature and humidity over-limit alarm indicator D41. Figure 4 As shown;

[0039] The collector of the first transistor Q41 is connected to one end of the temperature and humidity over-limit alarm indicator light D41, and the other end of the temperature and humidity over-limit alarm indicator light D41 is connected to VCC through the third current limiting resistor R41. The base of the first transistor Q41 is connected to pin 21 of the main control chip U01 through the fourth current limiting resistor R42, and the emitter of the first transistor Q41 is grounded.

[0040] Furthermore, when it is detected that the temperature or humidity exceeds the threshold, the No. 28 pin LED_WORK of the main control chip U01 outputs a high level, driving the first transistor Q41 to be turned on and emit a red light alarm.

[0041] The infrared transmitting and receiving module includes a transmitting circuit (such as Figure 5 As shown) and receiving circuit (as Figure 6 shown).

[0042] The transmitting circuit includes a PNP transistor Q31, a first current limiting resistor R31, a bias resistor R32, a second current limiting resistor R33 and an infrared signal transmitting tube D31. The collector of the PNP transistor Q31 is connected to VCC, the bias resistor R32 is connected between the collector and the base of the PNP transistor Q31, the base of the PNP transistor Q31 is connected to pin 18 of the main control chip U01 through the first current limiting resistor R31, the emitter of the PNP transistor Q31 is connected to one end of the infrared signal transmitting tube D31, and the other end of the infrared signal transmitting tube D31 is grounded through the second current limiting resistor R33.

[0043] Furthermore, the model of the infrared signal transmitting tube D31 is IR204-AL, and the output voltage of pin 18 of the main control chip U01 drives the base of the PNP transistor Q31 to control the emission of the infrared signal.

[0044] The receiving circuit includes an NPN transistor Q32, an infrared signal receiving tube D32, a blue light indicator D33, a fifth current limiting resistor R37, a voltage dividing resistor R36 and a normal pull-up resistor R38;

[0045] The base of the NPN transistor Q32 is connected to pin 5 of the main control chip U01 through the infrared signal receiving tube D32, and the base of the NPN transistor Q32 is also grounded through the voltage divider resistor R36. The emitter of the NPN transistor Q32 is grounded, one end of the blue light indicator D33 is connected to pin 5 of the main control chip U01, and the other end of the blue light indicator D33 is connected to the collector of the NPN transistor Q32 through the fifth current limiting resistor R37. One end of the normal pull-up resistor R38 is connected to the collector of the NPN transistor Q32, and the other end of the normal pull-up resistor R38 is connected to pin 5 of the main control chip U01.

[0046] The model of the infrared signal receiving tube D32 is 2CU321R-LM / D. The infrared signal receiving tube D32 and the voltage dividing resistor R36 form a voltage dividing circuit. When an infrared signal is received, the reverse photocurrent of the infrared signal receiving tube D32 increases sharply from the original nA level to the μA level, driving the NPN transistor Q32 to turn on, and the blue light indicator D33 serves as a communication indication.

[0047] like Figure 7 As shown, the power module includes an LDO chip U11, a battery line interface DB1, and a Schottky diode D1. Pin 1 of the LDO chip U11 is grounded, pin 2 of the LDO chip U11 is connected to pin 1 of the battery line interface DB1 through the Schottky diode D1, pin 3 of the LDO chip U11 is connected to VCC, pin 1 of the battery line interface DB1 is also connected to VBAT, and the battery line interface DB1 is grounded.

[0048] Among them, VBAT represents the battery voltage, VCC represents the power supply voltage, the Schottky diode D1 can effectively prevent the power line from being reversed, the LDO chip U11 provides a stable power supply for the infrared transmitting and receiving module, the temperature and humidity detection module and the main control module, and the power module also includes a fourth capacitor C11, a fifth capacitor C12 and a sixth capacitor C13. The two ends of the fourth capacitor C11 are respectively connected to pin 1 and pin 2 of the LDO chip U11, the fourth capacitor C11 and the fifth capacitor C12 are connected in parallel, and the two ends of the sixth capacitor C13 are respectively connected to pin 1 and pin 3 of the LDO chip U11. The fourth capacitor C11 is a 10uF capacitor, which can reduce power supply noise and ensure stable operation of the circuit. The fifth capacitor C12 is a 0.1uF capacitor, which can reduce high-frequency noise and ensure stable operation of the circuit. The sixth capacitor C13 is a 10uF capacitor, which can reduce power supply noise and ensure stable operation of the circuit.

[0049] DB1 is a battery line interface, a pair of through-hole pads with a spacing of 2.54mm. Figure 7 The test point is just a pad that is brought out to facilitate developers to debug the soldering flying wires.

[0050] The above description is merely a specific embodiment of the present invention, but the scope of protection of the present invention is not limited thereto. Any changes or substitutions within the technical scope disclosed in the present invention shall be covered by the scope of protection of the present invention. Therefore, the scope of protection of the present invention shall be based on the scope of protection of the claims.

Claims

1. A temperature and humidity detection circuit, characterized in that: include: Infrared transmitting and receiving module, temperature and humidity detection module, a main control module for controlling the infrared transmitting and receiving module and the temperature and humidity detection module, and a power supply module for providing power to the infrared transmitting and receiving module, the temperature and humidity detection module and the main control module; The infrared transmitting and receiving module is electrically connected to the main control module, the temperature and humidity detection module is electrically connected to the main control module, and the infrared transmitting and receiving module, the temperature and humidity detection module and the main control module are all electrically connected to the power module; The power module includes an LDO chip U11, a battery line interface DB1, and a Schottky diode D1. Pin 1 of the LDO chip U11 is grounded, and pin 2 of the LDO chip U11 is connected to pin 1 of the battery line interface DB1 via the Schottky diode D1. Pin 3 of the LDO chip U11 is connected to VCC, and pin 1 of the battery line interface DB1 is also connected to VBAT. The battery line interface DB1 is grounded. The temperature and humidity detection module also includes a first transistor Q41, a third current limiting resistor R41, a fourth current limiting resistor R42 and a temperature and humidity over-limit alarm indicator D41; The main control module includes a main control chip U01, the collector of the first transistor Q41 is connected to one end of the temperature and humidity over-limit alarm indicator D41, the other end of the temperature and humidity over-limit alarm indicator D41 is connected to VCC through the third current-limiting resistor R41, the base of the first transistor Q41 is connected to pin 21 of the main control chip U01 through the fourth current-limiting resistor R42, and the emitter of the first transistor Q41 is grounded; The infrared transmitting and receiving module, the temperature and humidity detection module, the main control module for controlling the transmission and reception of infrared signals, and the power module are installed on the PCB board.

2. A temperature and humidity detection circuit according to claim 1, characterized in that: Pin 1 of the main control chip U01 is connected to pin 2 of the SWD download plug-in J1 through the third pull-up resistor R03, pin 2 of the main control chip U01 is connected to pin 1 of the SWD download plug-in J1, pin 32 of the main control chip U01 is connected to pin 3 of the SWD download plug-in J1 through the fourth pull-up resistor R04, pin 29 of the main control chip U01 is connected to pin 4 of the SWD download plug-in J1, pin 28 of the main control chip U01 is connected to pin 5 of the SWD download plug-in J1 through the first capacitor C01, pin 28 of the main control chip U01 is also connected to pin 5 of the SWD download plug-in J1 through the second capacitor C02, pin 26 of the main control chip U01 is connected to pin 5 of the SWD download plug-in J1 through the third capacitor C03, pin 9 of the main chip U01 is the signal receiving port BOOT-RX of the BOOT interface, and pin 10 of the main chip U01 is the signal sending port BOOT-TX of the BOOT interface.

3. A temperature and humidity detection circuit according to claim 2, characterized in that: The temperature and humidity detection module includes a temperature and humidity detection chip U1, a first pull-up resistor R1, and a second pull-up resistor R2. Pin 1 of the temperature and humidity detection chip U1 is connected to pin 13 of the main control chip U01 through the first pull-up resistor R1, pin 6 of the temperature and humidity detection chip U1 is connected to pin 14 of the main control chip U01 through the second pull-up resistor R2, pin 2 of the temperature and humidity detection chip U1 is grounded, and pin 5 of the temperature and humidity detection chip U1 is connected to VCC.

4. A temperature and humidity detection circuit according to claim 1, characterized in that: The infrared transmitting and receiving module includes a transmitting circuit and a receiving circuit.

5. A temperature and humidity detection circuit according to claim 4, characterized in that: The transmitting circuit includes a PNP transistor Q31, a first current limiting resistor R31, a bias resistor R32, a second current limiting resistor R33 and an infrared signal transmitting tube D31. The collector of the PNP transistor Q31 is connected to VCC, the bias resistor R32 is connected between the collector and the base of the PNP transistor Q31, the base of the PNP transistor Q31 is connected to pin 18 of the main control chip U01 through the first current limiting resistor R31, the emitter of the PNP transistor Q31 is connected to one end of the infrared signal transmitting tube D31, and the other end of the infrared signal transmitting tube D31 is grounded through the second current limiting resistor R33.

6. A temperature and humidity detection circuit according to claim 4 or 5, characterized in that: The receiving circuit includes an NPN transistor Q32, an infrared signal receiving tube D32, a blue light indicator D33, a fifth current limiting resistor R37, a voltage dividing resistor R36 and a normal pull-up resistor R38; The base of the NPN transistor Q32 is connected to pin 5 of the main control chip U01 through the infrared signal receiving tube D32, and the base of the NPN transistor Q32 is also grounded through the voltage divider resistor R36. The emitter of the NPN transistor Q32 is grounded, one end of the blue light indicator D33 is connected to pin 5 of the main control chip U01, and the other end of the blue light indicator D33 is connected to the collector of the NPN transistor Q32 through the fifth current limiting resistor R37. One end of the normal pull-up resistor R38 is connected to the collector of the NPN transistor Q32, and the other end of the normal pull-up resistor R38 is connected to pin 5 of the main control chip U01.

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