FV-1 was designed for guitar pedals. Probably the only IC ever designed specifically for guitar pedals. It is used in many, many guitar pedal designs. I have built 3 with it, a multi-mode reverb, a multi-mode delay, and a rainbow machine. Rainbow machine doesn’t even need the eeprom. It just uses the default program.
I didn’t realize that Hawigo’s multi effect module used the FV-1.
Also, pedalpcb sells a pcb (and has the schematics if you want to make your own) that is a programmer/development platform for the FV-1. It is based around guitar pedals, though. May still get you going in the right direction if you need a development platform.
I don’t need PCBs, this is a one off at the moment, although I do have 6 more fv-1 chips to play with. I might build some add on effects modules for some of my synth designs, currently they are either effect less or using stripped down Behringer june-60 devices.
Shamelessly stole Hagiwos method for displaying parameters and added the patchname/number, bank number/effect and the effects mix, a tight squeeze. I’m thinking of putting a large 3 digit LED next to the display so you can see the current patch number from a distance.