Hacked a PCB board from a ConcertMate 980. No schematics to be found online. Found that it's a Casio rebrand, found the corresponding Casio schematics. Initially, I wanted to salvage the MIDI DIN ports, but I then had the idea of actually hacking the PCB itself as it already has the opto-isolator, the resistors and circuitry. Connected that to an Arduino Uno which was staying idle for a while and coded CV output with a higher-resolution than base MIDI. This goes in the VCF fcM Input jack, and also coded MIDI input parsing, as well as a trigger for the Arp so I can both trigger the Arp as well as control the VCF Cutoff externally with the Atmel micro-controller. Made two custom cables as well as a custom switch arrangement for the Arduino because the upload procedure fails badly when the hacked MIDI interface is connected.
Thought I would use the Alesis Micron for main sequencing, but using the Kurzweil instead was easier. So here's my MIDI-to-Arp Sync triggering, no commercial shield used at all:
Main Drum sequence & MIDI Clock: Kurzweil K2500XS
Backing sequence (pan right): Alesis Micron synced to MIDI clock.
Analog sequence: Korg Polysix using the Arp trigger only (all controls are done on the keyboard and knobs).
I only trigger on each note for now but it would be better to have the Arp trigger occur at subdivisions within each note duration.
On my Polysix, when I click the Arp button with the Arp trigger cable connected, a sustained note always sounds. When the trigger is deactivated by the uC, the note is there again. Is that normal?
Much fun,
Yash