[sdiy] Digi-Mod

[Eric Brombaugh]

Seb Francis wrote:
> Well at the moment I've done little more than write the framework for 
> the hardware, the basic ISRs, etc, enough really to test everything is 
> working.  I have a basic sampler that can record and play back, without 
> changing pitch.

Sounds like a good start!

> For ages I had this weird problem where the audio output would fade in 
> rather than play immediately when playback was triggered ... until I 
> realised the CODEC has a 'feature' where it auto-mutes after a certain 
> number of consecutive identical samples (it then fades in after a 
> mute).

I'm also using the CS4270 on my ARM/FPGA board & ran into the same 
thing. Although it's just a matter of tweaking a bit in the control 
registers to disable the feature, it's a bit annoying until you get 
around to it.

> I have to say that I haven't tested the CV output and MIDI parts as I'm 
> not planning to use them myself, but I'm sure there's no problem as the 
> CV output circuit is very simple (quite close to your 'dspicfun' board 
> actually), and the MIDI circuit is one I've used on many projects before.

Left as an exercise for those who need it.

Which reminds me - I've got to do some more firmware on the dsPICfun 
board at some point. Just been too wrapped up in the FPGA board lately...

Eric