The Bliptronome Kit converts ThinkGeek's Bliptronic 5000 LED Synthesizer to a fully-fledge Monome 40h. This is probably the cheapest way of getting a 40h (Bliptronic 5000 is $40 and the Bliptronome kit is $73). The kit was created by Wil Lindsay (a.k.a. Wait for VBLANK) and he has plenty of resources on his website straytechnologies. The full conversion took me maybe 2 ½ hours - with 1 hour just putting in the potentiometers (it was a little awkward, which is not the kit's fault).
The Bliptronome's firmware is a flawless conversion of the Arduinome firmware. ArduinomeSerial was running right away and my applications were receiving all the OSC messages without any problem. I changed a few lines in my Processing OscBeatSequencer and it worked.
Seeed Studio used to have almost all components to build you own Monome.
I used Unsped's Arduinome Shield.
|Arduinome Shield||64 LED Button Pad|