LM75A is a digital temperature sensor with built in analog to digital converter and I2C interface .It can provide an accurate temperature reading from -55 to +125 C. For similar design based on analog LM35 sensor click here. Also a version based on DH11 humidity and temperature sensor is available at this link. In this project a simple digital thermometer based on LM75A and Arduino platform will be shown. This circuit requires the following components: 16×2 LCD Display, Arduino UNO or compatible board and I2C temperature sensor module. LiquidCrystal.h and M2M_LM75A.h libraries are needed in order to compile the attached Arduino sketch. The code is also not too complicated. It takes a temperature reading every second and outputs it to the LCD display.
You can minimize the circuit complexity and the number of connection required further by using an LCD display with I2C module. In this case make sure that there is no collision between I2C bus addresses. I don’t have a precise thermometer to be used as a reference, however as can be seen from a short video the circuit seems to work correctly and you can see the temperature rising by touching the sensor with your fingers.
