HOW to Use NTC-MF52AT Thermistor on Raspberry Pi with ESP32
Overview
In the experiment, there is a NTC-MF52AT analog thermistor. We connect its signal terminal to the analog port of the ESP32 mainboard and read the corresponding ADC value, voltage value and thermistor value.
We can use analog values to calculate the temperature of the current environment through specific formulas. Since the temperature calculation formula is more complicated, we only read the corresponding analog value.
Working Principle
This module mainly uses NTC-MF52AT thermistor element, which can sense the changes of the surrounding environment temperature. Resistance changes with the temperature, causing the voltage of the signal terminal S to change.
This sensor uses the characteristics of NTC-MF52AT thermistor element to convert resistance changes into voltage changes.
Components
|
|
|
|
|---|---|---|
|
ESP32 Board*1 |
ESP32 Expansion Board*1 |
Keyestudio NTC-MF52AT Thermistor*1 |
|
|
|
|
|
3P Dupont Wire*1 |
Micro USB Cable*1 |
|
Connection Diagram
Test Code
//**********************************************************************************
/*
* Filename : Temperature sensor
* Description : Making a thermometer by thermistor.
* Auther : http//www.keyestudio.com
*/
#define PIN_ANALOG_IN 34
void setup() {
Serial.begin(9600);
}
void loop() {
int adcValue = analogRead(PIN_ANALOG_IN); //read ADC pin
double voltage = (float)adcValue / 4095.0 * 3.3; // calculate voltage
double Rt = (3.3 - voltage) / voltage * 4.7; //calculate resistance value of thermistor
double tempK = 1 / (1 / (273.15 + 25) + log(Rt / 10) / 3950.0); //calculate temperature (Kelvin)
double tempC = tempK - 273.15; //calculate temperature (Celsius)
Serial.printf("ADC value : %d,\tVoltage : %.2fV, \tTemperature : %.2fC\n", adcValue, voltage, tempC);
delay(1000);
}
//**********************************************************************************
Test Result
Connect the wires according to the experimental wiring diagram, compile and upload the code to the ESP32. After uploading successfully, we will use a USB cable to power on, open the serial monitor and set the baud rate to 9600. We need to press the reset button on the ESP32, then the serial monitor will display the thermistor’s ADC value, DAC value and voltage value, as shown below:
