In this project, Arduino will send the analog readings obtained from a Photo Resistor, also known as a Light Dependent Resistor (LDR), to the computer.

Parts required:

  • PhotoCell (or PhotoResistor)
  • 10K resistor
  • Breadboard
  • Arduino UNO
  • 5 wires(to connect it all together)

/// Code to run in Arduino
int LED = 2; // LED on PWM pin
int LDR = 0; // analog pin light sensor
int brightness = 0;

void setup() {

// the loop routine runs over and over again forever:
void loop() {

LDR = analogRead(A0); // read value from sensor

Serial.println(LDR); // print out the value you read

analogWrite(LED, LDR/4); // assigning the LED sensor value to 1/4 of the LDR value

delay(1); // delay in between reads for stability


Arduino Light Sensor is a project of IaaC, Institute for Advanced Architecture of Catalonia developed at Master in Advanced Architecture in 2015 of the Academic Program by:


Lalin Keyvan



Carmen Aguilar

Ramin Shambayati