Temperature Sensing Device


In order to make the temp. sensing device circuit the following components are needed.

Project description:

- by using Arduino and LM35 temperature sensor, I ‘m going to display the temperature readings in both Celsius and Fahrenheit scales. Also, I ‘m going to use RGB LED as an indicator for temperature being than 32 Celsius:

If temp is less than or equal 32 C >> RGB light is green

But if it exceeds that value >> RGB is going to turn RED.

Configuration of pinouts of:

  1. LM 35 temp. sensor.

  2. LCD.

  3. RGB LED.

LM 35 temperature sensor

LCD display



After knowing the configuration of the components, I drew the following circuit using fritzing, to help me during connecting the components to build my circuit up.

After that, I built the circuit as follows:


First, I connected the Arduino ground and 5v pins to the breadboard as I am going to use my laptop USB as the power source of circuit.


Following the fritzing schematic, I connected the LCD pinouts to the Arduino and the potentiometer for adjusting the brightness of the display.


Then, I connected the LM 35 output pin to Arduino A0 pin. And the other two terminals to GND and Vcc of breadboard.


The RGB legs then are connected as the blue, green, and red legs in series with 220ohm resistors to pin 8,9, and 10 respectively.


The GND leg of RGB to GND of breadboard.


I connected the Arduino to my laptop and uploaded the code:

the result

the LCD displays the room temp in both Celsius and Fahrenheit degrees and when room temp is less than 32 C the RGB is Green:


When Room temperature exceeds 32 C the RGB light turns into RED:

Follow the link below for a video that explains the whole thing. Enjoy it