Lots of projects use a Light Dependent Resistor (LDR) to sense light levels but don't really focus on how they work.
This project shows you how to use a Light Dependent Resistor (LDR) to sense light levels, measure those levels with the Arduino and print the measurements to the Serial port.
Arduino measures Voltages on pins A0 to A5; but the LDR is a variable resistor (varying with Light). So we need to convert the varying resistance to a voltage that the Arduino can measure.
We do that by using the LDR and a Resistor in a Potential Divider circuit.
By the way. If you like this Instructable, you might also like:
- Smart Home Thermostat : http://www.instructables.com/id/Smart-Home-Thermostat/
- Yun based Electricity Monitor with Cloud Support:http://www.instructables.com/id/Yun-based-Electricity-Monitor-with-Cloud-Support-T/
- Digital Thermometer for your Home: http://www.instructables.com/id/ArduinoRaspberry...
- Internet-Radio: http://www.instructables.com/id/Arduino-Raspberry...
- Your own "Wii-Remote" like control of a PC Flight Simulator http://www.instructables.com/id/Flight-Simulator-with-Arduino-and-Python/