Digital light intensity meter with a calibrated LDR

Shawon made a light intensity meter using an ATmega microcontroller to read a light-dependent-resistor and display the values on a 2X16 character display. To calibrate his LDR he used a digital light meter and a dimmable light source. This allowed him to plot the sensor output and properly calibrate his device.

This project is about a microcontroller based light intensity meter where an LDR light sensor is calibrated against an external photometer to obtain the intensity of incoming light in the unit of lux. The lux is the SI unit of illuminance and luminous emittance, and measures lumens per square meter (lm/m2). The microcontroller used in this project is ATMega8L and its firmware is written using mikroElektronika’s MikroC Pro for AVR compiler.

Join the Conversation

2 Comments

  1. I still have problems understanding lumens vs candella vs lumenous flux vs output in watts. :(

    Though, this is awesome! I will have to check out the math behind this in the source to get a better understanding.

Leave a comment

Your email address will not be published. Required fields are marked *

Notify me of followup comments via e-mail. You can also subscribe without commenting.