Shruthi Digital FX board

I already populated the passive RC filters on the board (for the CV lines). Then I read they are not used. Does it cause problems to leave them?

Also, how do I do this…“Please make sure that both the analog (CV1 to +5V) and digital (RX to +5V) ports of the filter and control boards are connected.”


Not sure about your first question.

The second part just means that both connectors on the board need to be present. So you have two sets of pins and headers linking the two boards.

You can leave the RC filters in place, they won’t make any difference.

I never quite got mine correctly working. Let me know if you have any luck.

@matrix12x What didn’t work?

Thanks all.

@6581punk I think I did a clean job of building the PCB, but when I connect it to a known good digital control pcb (like the one from my 4PM) I only get crazy noises.

When I am playing notes on my midi keyboard the little red led lights up on the Digital/FX board. the green light never seems to light. yet, even when I change patches, I only get the same digital hash. It does play in time with my notes though. I need to pick up a scope or something.

I burned the AT Mega 328 myself, so maybe I goofed on the fuses or something.

Use the makefile to burn the chips?

First i tried burning the fuses:
avrdude -B 100 -V -p m328p -c usbtiny -P usb -e -U lock:w:0x2F:m -e -u -U efuse:w:0xfd:m \\ -U hfuse:w:0xd7:m \\ -U lfuse:w:0xff:m \\ -U lock:w:0x2f:m

Then flash the code:
avrdude -B 100 -V -p m328p -c usbtiny -P usb -e -U flash:w:dsp_0.1.hex:i -U lock:w:0x2f:m

Oops. Forgot the 1n film caps. Anyone know if I can use ceramics instead?