Making LEDs react to sound

Thu 22 November 2012 // posts

Here is a collection of video demos of multiple sound reactive LED circuits I have played with.


First circuit. Uses an Arduino to read data from an electret microphone and react based on sound level. Sound sensibility is adjusted with a potentiometer.

The next circuit uses filters, a blue LED that reacts to lower frequencies, filtered with a low pass circuit, configured with a cutoff frequency of \~150Hz, while the red one reacts to higher frequencies, filtered by an high pass circuit, with a cutoff frequency set a little over 1.5KHz. The sound responsiveness is much better than the previous circuit.

The following circuit uses frequency filtering with high power LEDs. The circuit got a little more complex than the previous one due to power requirements (different transistors, power source, etc).