Tutorial : LDR Sensor Module

Step 1: Introduction

LDR sensor module is used to detect the intensity of light. It is associated with both analog output pin and digital output pin labelled as DO and AO respectively shows on the board. When there is light, the resistance of LDR will become low according to the intensity of light. The greater the intensity of light, the lower the resistance of LDR. The sensor has a potentiometer knob that can adjusted to change the sensitivity of LDR towards light.


  • Input Voltage: DC 3.3V to 5V
  • Output: Analog and Digital
  • Sensitivity adjustable





Step 2: Pin Definition

Picture of Pin Definition

Picture of Pin Definition




Step 3: Sample Hardware Installation (Analog Output)

Picture of Sample Hardware Installation (Analog Output)




Step 4: Sample Source Code

void setup()




void loop()


unsigned int AnalogValue;

AnalogValue = analogRead(A0);