fbpx

Procedure With Output

Schematic Diagram :

Program :

Open Arduino IDE and paste the following code.

#define LDR A0 //Light dependent resistor (LDR) connected to analog pin A0
#define LED 5 //LED connected to digital pin 5
int LDR_value; //variable to store result value read by LDR

void setup()
{
Serial.begin(9600); //intialise the serial port for communication
pinMode(LED, OUTPUT); // set LED as output
pinMode(LDR, INPUT); //set light dependent resistor as input

}

void loop()
{

LDR_value=analogRead(LDR); //read the data from analog pin A2 and store in LDR_value

if (LDR_value<=500) //if LDR_value value is less than or equal to 300 that means its dark outside so LED should be turn on

{
digitalWrite(LED, HIGH);//turn on the LED

Serial.println(“its dark turn on the LED”);// display “its dark turn on the LED” on serial monitor and set the cursor to the new line
Serial.println(“LDR value:”); //display “LDR value:” on serial monitor and set the cursor to the new line
Serial.println(LDR_value); // print the value of sensor

}
else //if LDR_value value is greater than 300 that means its bright outside so LED should be turn off
{
digitalWrite(LED, LOW); //turn off the LED

Serial.println(“its bright turn off the LED”); // display “its bright turn off the LED” on serial monitor and set the cursor to the new line
Serial.println(“LDR value:”); //display “LDR value:” on serial monitor and set the cursor to the new line
Serial.println(LDR_value); // print the value of sensor
}
delay(200); //delay

}

The logical flow of the program is very simple:

  • Get the brightness value from the sensor.

  • Display brightness value on the screen.

  • If the brightness value is less than 500, that means brightness is low, then power ON the LED.

  • If the brightness is greater than 500, that means its day time, then power OFF the LED.