USB Midi conversion for the Korg Poly61 synthesizer
This midi conversion uses a Teensy V3.2 to interface between the keys, arpeggiator and the cpu board. This will add the following functionality to your Korg Poly61:
USB Midi interface Hardware MIDI input Hardware MIDI thru (from the hardware MIDI input) Hardware MIDI out/thru (forwarded from the USB midi) MIDI synced arpeggiator (can be set to internal, 1/4, 1/8, 1/16, 1/32) SYNC/TRIGGER out MIDI port selectable (1 - 16 or OMNI)
The MIDI port and arpeggiator sync can be set at power on by holding the keys. C0 = ARP internal C#0 = ARP 1/4 D0 = ARP 1/8 D#0 = ARP 1/16 E0 = ARP 1/32
C2 = MIDI channel 1 ---> D#3 = MIDI channel 16 E3 = OMNI
I have included the code, schematic and a very raw pcb (i still have some available). There is a lot of space between the components and the pcb could be half it's current size :) You will need a Teensy 3.1/3.2 for this as these are still 5V tolerant.