Start of a new series of embedded arm computer: KontraComputer
Status: staging for Olimex A20 and old A10
Author: Winfried Ritsch
Date: 09/2015-
NOTE:Staging means, names and directories can change until it will be released.

Why Koco

Using embedded computer like ARM for Computermusic (CM) needs a reason.

  • If somebody wants to play CM over an embedded device with the help of a (mobile) computer he needs one like a Laptop or notebook, so why not play CM directly with this ?
  • If the embedded computer is networked it needs cables which are mostly larger and more weight than the embedded computer, so it looses it smallness factor.
  • If it want to play Sound over speakers with an embedded computer, the speakers are mostly bigger and more unhandy than the device, wo why using this small computers ?
  • If I want Interaction I can use a lot of wireless sensors, just out of the shop over bluetooth, Wifi, or microcontroller with wireless interfaces... etc, so no need of a embedded computer at the place ?
  • ...

Until now, I found no reason for such a device, but my intuitive feeling is that I need it, the only reason was to to build it contra (German: kontra) the arguments above, without reasoning, even art needs no reasoning [AWR], so I called it Kontra-Computer alias Koco.[1]


Experimental Koco Board

Target Features

  • Strictly Open hard and software
  • Touchscreen LCD
  • Audio Stereo out with XLR (maybe symmetric)
  • Audio Ins switchable: Mic, Line, Preamp
  • Sensor Connectors: Accelerator, Distance, Temperature Huminidy
  • battery powered with build-in charger over 5V supply


  • A20: Olimex A20-Lime2
  • touchscreen Olimex 4.3TS
  • onboard_codec Electronics used for interfacing the onboard codecs of Olimex A10+ boards.


multichannel audio boards
like https://github.com/whollender/SuperAudioBoard