TMP36 Temperature Sensor

Introduction

    One of the most used sensors in Arduino projects is the Temperature sensor. It comes in many different sizes and shapes to fit different project types, from small school projects to large industrial factories. This tutorial will show you how to use the sensor and how it works.

Theory of Operation

    Temperature sensors vary in the technology they use to measure temperature. The temperature sensor we’re using with the Arduino is TMP36. It’s a thermocouple temperature sensor.

    Thermocouples use two conductive wires, one is used to measure the heat and the other is used as a reference. When the first wire is heated, it generates voltage due to thermoelectric effect. That voltage is different from the voltage at the second reference wire. The voltage difference between the two wires is measured and signal-processed into a readable signal that can be read by the

Arduino.

Technical Details

•    Voltage Input: 2.7 V to 5.5 VDC
•    10 mV/°C scale factor
•    ±2°C accuracy over temperature
•    ±0.5°C linearity
•    Operating Range: −40°C to +125°C

Connections

Code

int sensorPin = A0;

void setup()
{
  Serial.begin(115200);
}
 
void loop()
{
 int reading = analogRead(sensorPin);  
 
 float voltage = reading * 5.0;
 voltage /= 1024.0; 
 
 float temperatureC = (voltage - 0.5) * 100 ;  //converting from 10 mv per degree with 500 mV offset
                                               //to degrees ((voltage - 500mV) times 100)
 Serial.println(temperatureC,1);// Serial.println(" degrees C");
 
 delay(100);                                     //waiting a second
}