[sdiy] ARM thru-hole options - was Propeller CPU

[Scott Gravenhorst]

Tom Wiltshire <tom at electricdruid.net> wrote:
>Do people think that we're better off using general-purpose MCUs 
>rather than moving onto DSPs? 
>
>The Freescale Symphony Soundbite has come up here several times, 
>and seems to be a powerful chip. I've got a dev board for it, but 
>so far it has stayed on the shelf whilst I do other stuff. 
>Getting to grips with a new platform is always the most painful 
>part of the whole process. 

I think Tom raises an excellent point.

I believe that 8 bit MCUs are designed for 8 bit microcontroller
applications.  Yes, I know one can make a synth out of many/most 8 bit
MCUs, but IMO, they are far less than optimal, especially if you need
16 bit arithmetic with 16x16 bit multiplies.  While this can be done
with 8 bit MCUs, it is slow.

I agree with Tom regarding platform learning curve - but in my
experience, it isn't really all that bad, I've done it with numerous 8
bit MCUs, doing it now with dsPIC and have done it with DSP on an FPGA.
 It takes some time, study, "hello-world" experiments, etc. but if
you've done it once, you can do it again.  In my opinion, of the
platforms I've used to date, the most powerful would be the FPGA.  I
have not, however, used a "real" DSP chip yet.

I also think it is a good idea to do some thinking about exactly what
do you want to accomplish.  Monosynth only?  Polysynth?  How many
voices?  How many and what kind of features?  and then look at
processor platforms that might be able to accomplish this.  I did this
back-asswards with the FPGA simply buying a dev board and diving in
head first, but I got very lucky in that the power of an FPGA is great
enough that all of my design desires could be met therein.  

I am personally attracted to dsPIC for smaller projects (monosynths,
low voice count polysynths), they can be DIP and the dsPIC can have
lots of good audio stuff already in the chip.  For anyone wishing to do
DSP for audio, the dsPIC is well worth reading about.


>On 20 Dec 2010, at 12:01, Neil Johnson wrote:
>
>> Hi,
>> 
>> nicolas wrote:
>>> There are quite a few through-hole-adapter/low-end-
>>> development-boards that have the right cost/convenience
>>> for my needs.  Some examples among many:
>> 
>> Another one from me: Olimex LPC-H2148
>> 
>> http://www.olimex.com/dev/lpc-h2148.html
>> 
>> Widely available:
>> 
>> http://www.sparkfun.com/products/676
>> 
>> 
>http://www.coolcomponents.co.uk/catalog/product_info.php?manufacturers_id=11&products_id=71

>> > http://www.dontronics-shop.com/lpc-h2148.html > > The LPC2148 
>isn't the latest and greatest ARM-powered microcontroller > out 
>there these days (did anyone else take up Terry's Freescale 
>offer? > Cheap way to get a Cortex-M4 dev.kit!). But its a 
>significant step > up from the AVR, and there is a lot of support 
>for it out there, e.g. > > http://jcwren.com/arm/ > > Cheers, > 
>Neil > -- > http://www.njohnson.co.uk > 
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-- ScottG
________________________________________________________________________
-- Scott Gravenhorst
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