[sdiy] Microchip DSP kit $60

[Eric Brombaugh]

Scott Gravenhorst wrote:
> "Barry Klein" <Barry.L.Klein at wdc.com> wrote:
>> Supposedly new DSP dev. kit for $60.
>> Looks like a decent kit for that much $$.
>> Anyone doing anything with it?
>> http://microchip.com/stellent/idcplg?IdcService=SS_GET_PAGE&nodeId=1406&dDocName=en534506
> 
> Barry,
> 
> Thank you for this.  
> 
> DSP people - is 16 KB RAM big/small/midsize?  
> 
> What sort of applications can we fit in this? 
> 
> Also, what does this mean:
>  "Low cost audio capture and play back circuitry using the 12 bit ADC and PWM Audio"
> 
> Specifically, "PWM" - pulse width modulation - is that how they make audio out?  Not sure
> what the implications for that are with respect to things like aliasing, noise and
> distortion.
> 
> Max sample rate of 48KHz isn't stellar, but it's usable.

Microchip dsPIC processors are fairly nice little parts. They're 
relatively inexpensive, available in DIP packages, have a decent 
instruction set that's easy to remember and come with a good complement 
of peripherals. Software development tools are free and the programming 
hardware is fairly inexpensive.

Downsides are that they're 16-bit processors so it's difficult to do 
excellent audio DSP with them and the various revs of the parts have 
interesting 'undocumented features' which sometimes require a bit of 
research to work around.

Overall I like them. You can do some amazing stuff with them if you are 
prepared to bang your head against the wall a little bit.

This new development system is probably a great way to get your feet wet 
with the dsPIC in audio applications. While 48kHz is a decent sample 
rate, I wouldn't expect great things from 12-bit converters and PWM 
output though. For studio-quality audio, some dsPICs have an I2S codec 
interface that's much better.

Eric