Interfacing LDR Sensor with Arduino | led dimmer LDR Sensor Arduino Code for Analog Output

Hello friends! Welcome back to ElectroDuino. This tutorial is base on Interfacing LDR Sensor with Arduino | LDR Sensor Arduino Code for Analog Output Read. Here we will learn how to connect the LDR Sensor module to the Arduino circuit diagram, and LDR Sensor Arduino code for Analog Output. Also, we will make a dark & light detector project using the analog output of the sensor..

Components Required

LDR Sensor Module or Photoresistor sensor Pin Diagram

How to use LDR Sensor with Arduino to Read Analog Output

Here we will connect the LDR sensor module with Arduino to read the Analog Output of the sensor. First of all, we connected the sensor Vcc pin to the Arduino 5v pin and the GND pin is connected to the GND pin. The analog output pin is connected to the Arduino analog pin to read the analog output value from the LDR sensor module.

Arduino LDR Sensor Circuit diagram for Analog Output

Circuit Wiring

How the LDR Sensor Works as a Dark & Light Detector using Sensor Digital Output value

In this circuit, the Sensor Analog Output pin is connected to the Arduino analog pin “A5”. LDR Sensor Analog Output change according to the changes of light intensity on the surface of the LDR. The sensor gives analog output value ranges from 0 to 1023 (0v to 5v), and prints this value on Arduino IDE serial monitor window. The LDR sensor gives a maximum analog output (1023) when no light falls on the surface of the LDR, and it will a minimum analog output(0) when light falls on the surface of the LDR.

The LED1(Green) and LED2(Red) are indicators, these are indicated light and dark respectively.

In the Arduino code, we need to take two analog values, one for the maximum analog value and another one for the minimum analog value. Here we will take 800 for maximum analog value and 300 for minimum analog value.

 If Arduino reads analog value greater than or equal to 800 from the sensor output pin, LED2(Red) will turn ON, and LED1(Green) will turn OFF, It means that it is dark. Else if Arduino reads analog value less than or equal to 300 from the sensor output pin, LED1(Green) will turn ON, and LED2(Red) will turn OFF, It means that it is Light.

LDR Sensor with Arduino Code

/* interfacing LDR sensor with Arduino | LDR Sensor Arduino Code for Analog Output
www.electroduino.com */ 
 int LDRSensor = A5;
 int LED1 = 5;
 int LED2 = 4;
 
void setup()
 {
  pinMode (LDRSensor, INPUT);
  pinMode (LED1, OUTPUT);
  pinMode (LED2, OUTPUT);
  Serial.begin (9600);
 }
 
void loop()
 {
   int Sensordata = analogRead (LDRSensor);
 
   Serial.print("Sensor value:");
   Serial.println(Sensordata);
 
 if (Sensordata <= 300)
  {
   digitalWrite(LED1, HIGH);
   digitalWrite(LED2, LOW);
  }
 
 else if (Sensordata >= 800)
  {
   digitalWrite(LED1, LOW);
   digitalWrite(LED2, HIGH);
  }
 }

Code Analysis

Output

• When high light intensity falls on the LDR, then LED1(Green) will turn ON and LED 2(Red) will turn OFF, It means that it is Light.
• When no light falls on the LDR sensor, then LED2(Red) will turn ON, and LED1(Green) will turn OFF, It means that it is dark.