In this tutorial we will see how to interface photo-resistor sensor with LED light and Control Brightness of LED using Photo-resistor. You can read previous tutorial on photo-resistor with Arduino.

you will need

  1. Arduino, (Optional)
  2. Breadboard,
  3. Jumper Wire,
  4. 10K ohms Resistor,
  5. Photo-resistor,
  6. LED.

Do connection as shown in circuit diagram.


Whenever light fall on sensor it will reduce resistance and reduce output voltage. And LED light will be dimmed or OFF. When there is no light on sensor, Photo resistor will have High resistance and High output voltage, Hence LED will ON. To understand this concept you can calculate with voltage divider formula.

All the parts and programming is same as previous tutorial. Even you don’t need Arduino for doing this project. You will need one LED light, Photo-resistor, 10k ohms resistor, 5v supply and jumper wire.

When I fall light on sensor LED light will OFF. When I move light from sensor it will again ON.

Keep learning keep making 🙂


Categories: Arduino