[sdiy] Microchip DSP kit $60 > AVR32

[Tom Wiltshire]

On 21 Mar 2008, at 16:35, Julian wrote:

> Do either of you, or anyone else, know a good place to start  
> reading about on this area (sparkfun gives me hardware, but very  
> little in the way of knowlege to even make choices)  Google (or at  
> least my search terms) isnt getting me very far.
>
> Again, what im looking for is some sort of development platform  
> where i can (hopefully) implament some audio processing, with  
> sufficient facilities to let me concentrate soely on the  
> programming side, rather than having to learn the hardware specifics 
> (dacs/adc/busses etc) before i even start.
>
> A kind of 'dummies guide to microprocessor driven effects boxes' if  
> you like!
>
> Thanks, Julian

Depends a bit how comfortable you feel with this sort of stuff or how  
much previous experience you've got. Have you done any assembly  
language? Do you write C programs?

I've been playing with the dsPICs for about a year, and found them  
pretty easy to learn. The board that started this thread would  
probably be a reasonable option to build a basic in/out digital  
effects box.

I've recently bought the Freescale Soundbite board that a few others  
on this list are using. It's a much more serious DSP, and would make  
a rackmount digital effects processor with the addition of just a  
power supply and a rack case. It has 4 stereo ins and four stereo  
outs, and optical digital in/out if you want it. The only problem  
would be controlling it, for which you need a front panel with knobs  
and switches connected to another processor which then talks to the  
DSP via SPI or I2C.

That last point makes the dsPIC more appealing. You can simply  
connect the A/D inputs to pots to give a 0-5V CV and then use the ADC  
values to control parameters. This makes life easier. I used the  
30F4013, which has 13 12-bit A/D channels for control CVs and  
includes the Codec interface to talk to an output audio DAC.

I can't comment on the ARM chips, as I haven't used them since the  
Acorn Archimedes! I'm sure they're at least as good.

Regards,
Tom