Something I've been dreaming about is finally playable. I call it: Isotar.

Isotar is an usb midi controller. You can hold it like a (small) guitar.

On the left are keys (12.7 mm buttons) ranging from A0 below C1 to D3 above C3, so just over 2 octaves.
The bottom row ranges from A0 to C2. The middle row is 7 semitones / a quint higher: E1 to G2. The top row is again 7 semitones higher: B1 to D3. Thanks to this layout it's easy to play a note and its Fifth.

All this is handled by a Teensy 3.1 and send as midi over usb.

To the right are 4 wires arranged as strings on a guitar. touching the wires is registered (capacitive sensing) by the Teensy and translated to note messages. The notes are simply the same as those played on the left but 2 octaves higher. When playing 3 notes left, the 4th wire plays the 1st wire plus 1 octave. When playing 2 notes left, the other two wires play the same notes another octave higher.
To the far right is a wire. Touching this wire means the Teensy instantly sends a note off after a (wire) note on. So it mutes the sound.


This page is presented for my personal enjoyment. I hope this page will also be an inspiration for diy-ers all over the world. This page is not meant to be a manual, so please don't contact me for guidance or support.
Thank you and enjoy.