Portable temperature and humidity monitor circuit

Abstract

The utility model relates to a portable humiture monitor circuit, comprising a temperature sensor used for sensing ambient temperature; the humidity sensor is used for sensing environment humidity; the first resistor R1 is connected with the temperature sensor in series to form a first branch; the second resistor R2 is connected with the humidity sensor in series to form a second branch; the micro-control chip is used for collecting the connection of the two ends of the first resistor R1 and the second resistor R2, and the micro-control chip is used for collecting the voltage of the two ends of the second resistor R2, and the micro-control chip obtains the temperature value and the humidity value of the temperature sensor and the humidity sensor through calculation; and the display is used for displaying the temperature value and the humidity value. According to the portable temperature and humidity monitor circuit, the micro-control chip capable of collecting temperature and humidity is adopted, the complexity of the circuit is reduced, external interference is also reduced, measured data are stable and accurate, the accuracy of temperature and humidity measurement is improved, the circuit design is reliable, and the portable temperature and humidity monitor circuit is worthy of popularization.

Description

Technical Field

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

[0002] Temperature and humidity detection devices can obtain environmental temperature and humidity information, playing an important role in guiding industrial production operations. A humidity sensor samples the ambient humidity value and combines it with the temperature sample value for comprehensive processing. Finally, a temperature and humidity control signal is generated to achieve temperature and humidity control.

[0003] With the continuous development of science and technology, the measurement of temperature and humidity has the following problems in practical applications:

[0004] 1. Traditional analog humidity sensors generally require not only the design of signal conditioning circuits, but also complex calibration and calibration processes. Their measurement accuracy is difficult to guarantee, and their linearity, repeatability, interchangeability, consistency, etc. are often unsatisfactory. Circuit design is especially important in temperature and humidity systems. How to avoid the introduction of noise and other interference signals is also one of the prerequisites for ensuring system accuracy.

[0005] 2. Traditional temperature and humidity detection is measured in the form of a temperature and humidity module. This test circuit requires an oscillation circuit, a drive circuit, and an amplifier circuit. The humidity module circuit is relatively complex, with many components, a complex production process, and a relatively high cost.

[0006] 3. At present, the existing technology uses thermistors and humidity-sensitive capacitors to measure temperature and humidity respectively. This temperature and humidity measuring device is still competent in situations where the accuracy requirements are not high, but its shortcomings are more prominent in situations where the accuracy requirements are relatively high. Moreover, when it comes to the detection of two parameters at the same time, two independent sensors and independent data processing circuits must be used, which greatly increases the design complexity of the measuring device. Utility Model Content

[0007] Therefore, the technical problem to be solved by the present invention is to overcome the problem that in the process of measuring temperature and humidity in the prior art, the circuit design is complex and it is impossible to take both cost and measurement stability into consideration.

[0008] In order to solve the above technical problems, the present invention provides a portable temperature and humidity monitor circuit, comprising: a temperature sensor for sensing ambient temperature; a humidity sensor for sensing ambient humidity; a first resistor R1, which is connected in series with the temperature sensor to form a first branch; a second resistor R2, which is connected in series with the humidity sensor to form a second branch; a microcontroller chip, which is connected to both ends of the first resistor R1, and the microcontroller chip is used to collect the voltage across the first resistor R1, the microcontroller chip is connected to both ends of the second resistor R2, and the microcontroller chip is used to collect the voltage across the second resistor R2, the microcontroller chip calculates the temperature and humidity values ​​of the temperature sensor and the humidity sensor; a display, which communicates with the microcontroller chip, and the display is used to display the temperature and humidity values ​​calculated by the microcontroller chip. The portable temperature and humidity monitor circuit of the present invention uses a microcontroller chip that can collect both temperature and humidity, which reduces the complexity of the circuit and reduces external interference, making the measurement data stable and accurate, improving the accuracy of temperature and humidity measurement, and the circuit design is reliable and worthy of promotion.

[0009] In one embodiment of the present invention, the microcontroller chip has three signal input terminals.

[0010] In one embodiment of the present invention, the first branch, the second branch, and the first signal input terminal of the microcontroller chip intersect at a first voltage collection point V1.

[0011] In one embodiment of the present invention, the second signal input terminal of the microcontroller chip intersects with the line between the first resistor R1 and the temperature sensor to form a second voltage collection point V2.

[0012] In one embodiment of the present invention, the third signal input terminal of the microcontroller chip intersects with the line between the second resistor R2 and the humidity sensor to form a third voltage collection point V3.

[0013] In one embodiment of the present invention, the first voltage collection point V1 is connected to a battery, and the battery provides a +3.7V power supply.

[0014] In one embodiment of the present invention, the first end of the temperature sensor is connected to the first resistor R1, and the second end of the temperature sensor is connected to GND. The first end of the humidity sensor is connected to the second resistor R2, and the second end of the humidity sensor is connected to GND.

[0015] In one embodiment of the present invention, the microcontroller chip is used to collect the voltage of the first resistor R1 from the first voltage collection point V1 and the second voltage collection point V2, and the microcontroller chip is used to collect the voltage of the second resistor R2 from the first voltage collection point V1 and the third voltage collection point V3.

[0016] In one embodiment of the present invention, the internal resistance of the temperature sensor is R NTC , the R NTC =(resistance of the first resistor R1 * voltage value of the second voltage collection point V2) / (voltage value of the first voltage collection point V1 - voltage value of the second voltage collection point V2).

[0017] In one embodiment of the present invention, the internal resistance of the humidity sensor is R RNH , the R RNH =(resistance of the second resistor R2*voltage value of the third voltage collection point V3) / (voltage value of the first voltage collection point V1-voltage value of the third voltage collection point V3).

[0018] The above technical solution of the utility model has the following beneficial effects compared with the prior art:

[0019] The portable temperature and humidity monitor circuit described in the utility model has the following advantages: 1. the circuit design is simple and reliable; 2. it is powered by ordinary batteries and can be applied to a variety of complex environments, including closed environments; 3. it is inexpensive; 4. it can be remotely monitored and monitored in real time; 5. it can be applied to the input ports of various MCUs; in addition, the circuit components are all conventional devices, which are easy to replace and purchase, and the manufacturing cost is reduced. BRIEF DESCRIPTION OF THE DRAWINGS

[0020] In order to make the content of the utility model easier to understand, the utility model is further described in detail below based on the specific embodiments of the utility model and in conjunction with the accompanying drawings, wherein

[0021] Figure 1 This is a circuit diagram of a portable temperature and humidity monitor circuit in a preferred embodiment of the present invention.

[0022] Description of the accompanying drawings in the specification: temperature sensor 1, humidity sensor 2, first resistor R1, second resistor R2, microcontroller chip 3, display 4, battery 100. DETAILED DESCRIPTION

[0023] The present invention will be further described below with reference to the accompanying drawings and specific embodiments so that those skilled in the art can better understand the present invention and implement it. However, the embodiments are not intended to limit the present invention.

[0024] Reference Figure 1As shown, the portable temperature and humidity monitor circuit of the present invention includes several main electrical components: a temperature sensor 1, a humidity sensor 2, a first resistor R1, a second resistor R2, a microcontroller chip 3 and a display 4; the temperature sensor 1 is used to sense the ambient temperature; the humidity sensor 2 is used to sense the ambient humidity; the first resistor R1 is connected in series with the temperature sensor 1 to form a first branch; the second resistor R2 is connected in series with the humidity sensor 2 to form a second branch; the microcontroller chip 3 is connected to both ends of the first resistor R1, and the microcontroller chip 3 is used to collect the voltage across the first resistor R1, the microcontroller chip 3 is connected to both ends of the second resistor R2, and the microcontroller chip 3 is used to collect the voltage across the second resistor R2, and the microcontroller chip 3 calculates the temperature value and humidity value of the temperature sensor 1 and the humidity sensor 2; the display 4 communicates with the microcontroller chip 3, and the display 4 is used to display the temperature value and humidity value calculated by the microcontroller chip 3.

[0025] In the above circuit, the first voltage collection point V1 is connected to the battery 100, which provides a +3.7V power supply. The first end of the temperature sensor 1 is connected to the first resistor R1, and the second end of the temperature sensor 1 is connected to GND. The first end of the humidity sensor 2 is connected to the second resistor R2, and the second end of the humidity sensor 2 is connected to GND.

[0026] The temperature sensor 1 is a sensor for sensing temperature and is powered by the above-mentioned +3.7V battery 100. The first resistor R1 is connected in series with the temperature sensor 1. Therefore, the first resistor R1 limits the current and divides the voltage of the temperature sensor 1 to protect the temperature sensor 1 and prevent the temperature sensor 1 from being burned.

[0027] The humidity sensor 2 is a sensor for sensing humidity and is powered by the above-mentioned +3.7V battery 100. The second resistor R2 is connected in series with the humidity sensor 2. Therefore, the second resistor R2 is a current limiter and a voltage divider for the humidity sensor 2 to protect the humidity sensor 2 and prevent the humidity sensor 2 from being burned.

[0028] In the above circuit, the microcontroller chip 3 has three signal input terminals. The three signal input terminals of the microcontroller chip 3 are connected in such a way that the first branch, the second branch, and the first signal input terminal of the microcontroller chip 3 intersect at a first voltage collection point V1. The second signal input terminal of the microcontroller chip 3 intersects with the line between the first resistor R1 and the temperature sensor 1 to form a second voltage collection point V2. The third signal input terminal of the microcontroller chip 3 intersects with the line between the second resistor R2 and the humidity sensor 2 to form a third voltage collection point V3.

[0029] In the above circuit, the microcontroller chip 3 is used to collect the voltage of the first resistor R1 at the first voltage collection point V1 and the second voltage collection point V2, and the microcontroller chip 3 is used to collect the voltage of the second resistor R2 at the first voltage collection point V1 and the third voltage collection point V3.

[0030] The internal resistance of temperature sensor 1 is R NTC , the R NTC =(resistance of the first resistor R1 * voltage value of the second voltage collection point V2) / (voltage value of the first voltage collection point V1 - voltage value of the second voltage collection point V2).

[0031] The internal resistance of humidity sensor 2 is R RNH , the R RNH =(resistance of the second resistor R2*voltage value of the third voltage collection point V3) / (voltage value of the first voltage collection point V1-voltage value of the third voltage collection point V3).

[0032] Through the above circuit structure, the principle of temperature and humidity display is:

[0033] When the circuit is working properly, it is powered by a conventional battery. As the temperature of the surrounding area increases, the internal resistance of the temperature sensor 1 will decrease accordingly; or as the temperature of the surrounding area decreases, the internal resistance of the temperature sensor 1 will increase accordingly. Each temperature of the temperature sensor 1 will correspond to a unique internal resistance value. The microcontroller chip 3 will automatically collect the first voltage collection point V1 and the second voltage collection point V2 at both ends of the first resistor R1, and calculate the internal resistance value of the temperature sensor 1 at this time, that is, R NTC =(resistance of first resistor R1 * voltage value of second voltage collection point V2) / (voltage value of first voltage collection point V1 - voltage value of second voltage collection point V2). Then, according to the temperature internal resistance conversion formula in the specification of temperature sensor 1, the corresponding temperature value is converted using the internal resistance value of temperature sensor 1 at this time. Then, through communication between microcontroller chip 3 and display 4, the current temperature is displayed on display 4.

[0034] When the circuit is working normally, it is powered by a conventional battery. As the temperature around it rises, the internal resistance of the humidity sensor 2 will decrease accordingly, and as the humidity around it rises, its internal resistance will also decrease accordingly; or as the temperature around it drops, its internal resistance will increase accordingly, and as the humidity around it drops, its internal resistance will also increase accordingly. Under each temperature and humidity condition, the humidity sensor 2 will correspond to a unique internal resistance value. The microcontroller chip 3 will automatically collect the first voltage collection point V1 and the third voltage collection point V3 at both ends of the second resistor R2, and calculate the internal resistance value of the humidity sensor 2 at this time, that is, R RNH=(resistance of second resistor R2 * voltage value of third voltage collection point V3) / (voltage value of first voltage collection point V1 - voltage value of third voltage collection point V3). Then, based on the temperature sensed by temperature sensor 1 and the temperature-humidity internal resistance conversion formula in the specification of humidity sensor 2, the corresponding humidity value is converted using the internal resistance value of humidity sensor 2. Then, through communication between microcontroller chip 3 and display 4, the humidity at the time is displayed on display 4. In this way, both the temperature and humidity at the time are displayed on display 4.

[0035] Obviously, the above embodiments are merely examples for clarity of explanation and are not intended to limit the implementation methods. Those skilled in the art will readily appreciate that other variations or modifications based on the above descriptions are possible. It is not necessary and impossible to enumerate all implementation methods here. Obvious variations or modifications arising therefrom remain within the scope of protection of the present invention.

Claims

1. A portable temperature and humidity monitor circuit, characterized in that: include: A temperature sensor, which is used to sense the ambient temperature; Humidity sensor, which is used to sense ambient humidity; A first resistor R1, connected in series with the temperature sensor to form a first branch; A second resistor R2 is connected in series with the humidity sensor to form a second branch; a microcontroller chip connected to both ends of a first resistor R1 and configured to collect a voltage across the first resistor R1; a microcontroller chip connected to both ends of a second resistor R2 and configured to collect a voltage across the second resistor R2; and a microcontroller chip calculating temperature and humidity values ​​of the temperature sensor and the humidity sensor; The display communicates with the microcontroller chip, and is used to display the temperature value and the humidity value calculated by the microcontroller chip.

2. The portable temperature and humidity monitor circuit according to claim 1, characterized in that: The microcontroller chip has three signal input terminals.

3. The portable temperature and humidity monitor circuit according to claim 2, characterized in that: The first branch, the second branch and the first signal input terminal of the microcontroller chip intersect at a first voltage collection point V1.

4. The portable temperature and humidity monitor circuit according to claim 3, characterized in that: The second signal input terminal of the microcontroller chip intersects with the line between the first resistor R1 and the temperature sensor to form a second voltage collection point V2.

5. The portable temperature and humidity monitor circuit according to claim 4, characterized in that: The third signal input terminal of the microcontroller chip intersects with the line between the second resistor R2 and the humidity sensor to form a third voltage collection point V3.

6. The portable temperature and humidity monitor circuit according to claim 3, characterized in that: The first voltage collection point V1 is connected to a battery, which provides a +3.7V power supply.

7. The portable temperature and humidity monitor circuit according to claim 1, characterized in that: A first end of the temperature sensor is connected to the first resistor R1 , and a second end of the temperature sensor is connected to GND. A first end of the humidity sensor is connected to the second resistor R2 , and a second end of the humidity sensor is connected to GND.

8. The portable temperature and humidity monitor circuit according to claim 5, characterized in that: The microcontroller chip is used to collect voltages at the first voltage collection point V1 and the second voltage collection point V2 to obtain the voltage of the first resistor R1 , and the microcontroller chip is used to collect voltages at the first voltage collection point V1 and the third voltage collection point V3 to obtain the voltage of the second resistor R2 .

9. The portable temperature and humidity monitor circuit according to claim 8, characterized in that: The internal resistance of the temperature sensor is R NTC , the R NTC =(resistance of the first resistor R1 * voltage value of the second voltage collection point V2) / (voltage value of the first voltage collection point V1 - voltage value of the second voltage collection point V2).

10. The portable temperature and humidity monitor circuit according to claim 9, characterized in that: The internal resistance of the humidity sensor is R RNH , the R RNH =(resistance of the second resistor R2*voltage value of the third voltage collection point V3) / (voltage value of the first voltage collection point V1-voltage value of the third voltage collection point V3).

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