DIY Arduino Project: Using LDR (Light Dependent Resistor) to Detect Light Levels

Introduction:

In this tutorial, we will learn how to implement an LDR (Light Dependent Resistor) with an Arduino to sense light levels. The LDR varies its resistance depending on the amount of light incident on it, and thus it can be used in different applications such as automatic lighting, light sensors, and so on!

Components Required:

Arduino board (Uno, Nano, etc.)

LDR (Light Dependent Resistor)

10k Ohm Resistor

Breadboard

Jumper wires

USB cable for Arduino programming

Circuit Diagram:

Arduino code

int ldrPin = A0;

int ldrValue = 0; 

void setup() {

  Serial.begin(9600); 

}

void loop() {

  ldrValue = analogRead(ldrPin); 

  Serial.println(ldrValue); 

  delay(500); 

}

Circuit Connections (Steps):

• Step-by-Step Wiring Instructions:

1. Connect one terminal of the LDR to the 3.3V pin of the Arduino.

2. Connect the other terminal of the LDR to A0 (analog pin) and the GND (ground).

3. Place a 10k Ohm resistor between A0 and GND to form a voltage divider.

Testing the Circuit:

• Explain how to test the project after uploading the code to the Arduino.

• Once the code is uploaded, open the Serial Monitor in the Arduino IDE.

• The LDR will give values based on light intensity. A higher value means more light, and a lower value means less light.

Testing the Circuit:

• Explain how to test the project after uploading the code to the Arduino.

• Once the code is uploaded, open the Serial Monitor in the Arduino IDE.

• The LDR will give values based on light intensity. A higher value means more light, and a lower value means less light.

Conclusion:

• Wrap up the project and encourage readers to try variations, such as using the LDR to control LEDs or create a light-sensitive alarm.