Lux Meter Based on Microcontroller

The project was designed with AVR microcontroller to create a lux meter that will be used to measure any illumination level.

A visible component that is defined in radiant flux or light power is termed as the luminous flux that is divided by relative sensitivity of human eyes over the visible spectrum. This lux meter measures the level of luminous flux covering a surface area. This signifies that the lux is well fit to light level perceived by human eyes.

An ordinary silicon photo diode is being used for the spectra response although there is a difference when compared with human eyes, and cannot be used for the lux meter since some photo diodes for illumination sensor have color compensation filter on the window to correct its spectra response. In short mode, the photo diode outputs light current that is proportional to input light power.

The output current is converted to voltage using this lux meter, then captured by a microcontroller and display it in terms of flux. A 9V battery is used to power the lux meter and the battery is made to contact with 2 pieces of springs to reduce space.

Rest of the project