DIY visual metronome
This is a box i made for Petter Vågan of the fjords. It is a box that basically will blink one set of LEDs if it recieves a MIDI note creater than C3 and another set of LEDs if it recieves a note equal to or lower than C3. It is meant to be used as a metronome or as a visual cue. The idea being that you set up a MIDI track in you sequencer that will send notes to the led so you can see the tempo/beat without it having to make any sound.
To make this i used a couple of transistors to switch the power on and of for the LEDs. and an Arduino to recieve the MIDI and turn the transistors on and off.
here is a crude drawing/schematic of the circuit:
In the above schematic i have of course left out the circuitry to make the atmega work. if you are wondering how to do that, then look here.
I am on tour right now and the arduino code that i wrote for this is at gome, but ill post it as below as soon as i get the chance.
p.s. you will need Francois Bests awesome MIDI library for the arduino to make this work. http://playground.arduino.cc/Main/MIDILibrary