The effects processor I’m not building this month.

In my last post, I mentioned that I had a good idea shortly after declaring “no new projects for a little while.”

Doesn’t mean I can’t talk about it. And hey, maybe one of you readers will take up the torch and design the schematic, PCB and/or firmware for me, so that when I clear my project backlog, it’s ready to go!

I’ve gotten really interested in the Spin Semiconductor FV-1 effects processor IC. It’s got built-in ADCs and DACs (so it’s a one-chip solution unlike some others), and if I’m reading the information on the web correctly, they almost seem to be encouraging the equivalent of a ‘clock bend’. I’m sort of curious as to how slowly it can be clocked – their examples don’t go below 20 kHz, but I wonder how lo-fi one could get it. I should ask on the messageboard…

Here’s kind of the feature set I was imagining:

• Switchable clock rate, between a fixed clock (at the suggested 32768 kHz or maybe better if you’re some kind of audiophile type), and the variable schmitt trigger clock outlined on the website, possibly tweaked to go lower if that’s technically feasible. Hot-switching between modes need not be required- I’d be cool with having to power-cycle it when changing clock mode from fixed to variable.
• The FV-1 on its own supports the use of a Serial EEPROM for additional effects programs. Change this to some kind of bank-switching multiplexing arrangement to allow multiple Serial EEPROMs to be used.
• Front panel/microcontroller. Use something like an ATMega168 (preferably with Arduino-type bootloader so upgrades to the firmware are easy, and include the headers for an FTDI programming cable!)  to control a 2×20 character LCD panel, and set the bank/program numbers. If you need more inputs, outputs or memory, feel free to use something bigger (ATMega644p in a Sanguino arrangement, etc.) Don’t worry about program names for the external banks. “BANK 3, PROGRAM 4” is fine. Feel free to use whatever menu navigating mechanism you want (buttons, pots, etc.)
• Additional features would be up to you. If you can add a simple mechanism for uploading new effects programs to the Serial EEPROMs (especially from Mac OS X), that would win, but I’ll live with the possibility of using a separate EEPROM writer and removing/inserting the ICs.

A starting point for looking into might be this one, but I think I want mine in a 1U rack form factor – I’ve got too many desktop doodads already, and it’s time to get vertical. This post also has some tantalizing ideas (Arduino as EEPROM writer! Write your DSP code  in Java!) but they’re not released yet.

So, there’s my idea.