Monday, 5 November 2007

First 'product' - das Kontroller

In addition to the drum machine, I promised a friend of mine to build him a specialized midi controller (actually, it was the controller that kicked off everything). I spend a lot of time working on the controller, which uses the same keyboard logic as the prototype and the drum machine.

The controller was finished the 11th of september 2006, exactly one year after we started working on it, and was named 'das Kontroller' as an inside joke refering to the blank-keys-keyboard das Keyboard.

I created a controller PCB using the free (but proprietary) PCB editor from, and had them etch me three PCBs:

This became the 'brain' of das Kontroller and worked flawlessly. It contained a midi interface, a serial rs232 interface as well as possibilites to connect a standard character LCD. The LCD has not been tested but everything else works flawlessly.

One thing was missing from the PCB though. Due to the way EasyPCB prices their PCBs, I desided that I would not have room for the keyboard-scanning ics on the controller, which only measures 6 * 10 cm.

For the keyboard, I designed (again in Illustrator...) an approximately 30 * 20 cm PCB, which I transfered to a blank PCB using photo paper and a laser printer, and etched at home. I then drilled about 1500 holes by hand, to fit close to 100 keys ands LEDs, and 8 potentiometers (faders). Unfortunately, I screwed up the layout somewhat and had to do some modifications using extremely thin modification wires (click for large images):

After fixing the design errors, das Kontroller now works as intended. The total price ended at about NOK 7000 (approx USD 1100), of which the majority was the enclosure and keys.

The finished result can be viewed here:
and here

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