Christmas syncs to MIDI keyboard

After the fun of my Christmas Tree with IP address in 2013, I decided a project along the same lines but more interactive was in order for 2014. I used the same Christmas lights and MOSFETs but used an Arduino this time instead of a Raspberry Pi.

I used a Sparkfun MIDI Shield (which includes the necessary diodes / resistors / opto-isolators) to receive MIDI data on an Arduino serial pin.

The initial idea was to cycle the light colours each time a Note On message was received. This didn't take into account chords which would cause the colours to cycle very quickly so a check was added to stop the colours cycling if it was less than 25ms since last time.

This implementation does not correctly handle things like Running Status and some other messages so the lights do not always flash quite as expected. But this was as far as I got before Twelfth Night!

I am improvising on the minor Blues scale on D.