[sdiy] Microcontrollers

[Paul Maddox]

Nick,

> I am in the decision making stage of a huge polysynth project for my
> self.  I was wondering what you guys think would be a good
> mirocontroller to use in this type of undertaking.  I only hve
> experiance with basic stamps and pc programming, so i really need to
> know what chip to study up on.

*HUGE* can of worms this one...

What you shoudl do is make a list of whats important to you...
1) how fast does it need to be?
2) how much program space does it need?
3) how much SRAM?
4) how many IO pins?
5) any other functions?

then look at other things
1) how much are the chips?
2) how much is the evaluation board?
3) what compilers are out there?
4) what support does the manufacturer offer?

If you've done any C programming you shoudl be ok... MOST
microcontrollers ahve some decent compilers available..

OK so heres what I use
Atmel AVR range, reasons
1) its fast, 1 instruction per cycle, so 8Mhz = 8MIPS
2) for me the 8515 was enough 8K of code, though for my poly synth Im look
at a 32K version (Mega103, or Mega128)
3) the 8515 had 512bytes of sram, it doesnt sound much, but it was ample.
4) the 8515 has 4 bidirectional 8bit ports, I actually had two spare pins
after :-)
5) most of the AVR range have on board hardware UART, so adding midi was a
doddle...

other stuff,
1)The chips are reasonable, if you buy them from impact memec you can get
the 8515-8pc for about 5UKP each.
2) The evaluation board (stk200) is about 50 quid, you get a chip, board
with LEDs /Switchs, jumpers a good thing to start with.
3) I used the Codevision Compiler (http://infotech.ir.ro) its cheap and very
good..
4) the support from atmel isnt that good, but there are plenty of places on
the web (avr mailing list, Avrfreaks.com) to get great help.

You will get many many replies...
you should base your decision on what YOU see as critical for your system..

Ive got a few bits of AVR projects on my page if you want to have a look,
under 'other projects'
Http://www.wavesynth.com/modulus/

Hope this helps
Paul Maddox
_______________________________________
Wavesynth home page;-
    Http://www.wavesynth.com
Modulus synthesizers home page;-
    Http://www.wavesynth.com/modulus
Waveterm C Project page;-
    Http://www.waveterm.com