A 2 dollar 68 cent chinesse keyboard with the original micro controller removed.
The Arduino is scanning the keys and buttons and generating all of the sound in the clip.
Current controls include -
37 Keys which can be transposed up and down by upto 7 octaves to access the full range of midi notes - I am using the transpose keys in the video to shift the arpeggio up and down the octaves 4 Waveforms - Sine, Square, Ramp, Dirty Triangle Adjustable Arpeggio speed - very fast sound like a chord or chorus effect, slower speeds are what you hear in the clip.
Lots of potential for additions, I will also do a series of blog posts on how to build this that could be applied to most cheap keyboards.
I have started this currently empty blog post as a place holder for part 1 of the build -
I will be combining this with the modular synth concept I am working on here -