[sdiy] WHICH PIC/UCONTROLLER should I buy today

[Tom Wiltshire]

I definitely recommend the 16-bit dsPIC 33FJ128GP802 for this. It does everything you want. I pay less than £5 for them in small quantities. I'm currently working on a synth voice based on this chip, with a view to building a polyphonic synth.

http://www.electricdruid.net/images/dualchannelvoice.jpg

There are other "audio" chips on the microchip website (below). These either have a stereo 16-bit (14-bit accurate) DAC or a CODEC interface.

http://www.microchip.com/ParamChartSearch/chart.aspx?branchID=8095&mid=14&lang=en&pageId=75

HTH,
T.

On 9 Aug 2010, at 14:46, dan snazelle wrote:

> OK so using PWM is going to be OUT then if I want anything that is HIGH quality audio (which I DO)
> 
> basically, I am in search of a chip (or a few) that could make high quality MOD sources OR high quality SINE, TRI, and other waves. (grainy is only fine if you want it to be grainy)
> 
> So what about the small 16bit Up's?
> 
> 
> The SPIN fv-1 can make very high quality SINGLE waveforms but at around $15-17 bucks a piece plus the cost of an eprom (which you need just to run your own program) and all the support circuitry, having 4, 5, 6, and above 
> sound sources could get very, very expensive.
> 
> So I figured DSP chips were NOT the way to go for producing basic waveforms, etc.
> 
> I have bumped into a few SDIY uP pages but none of them go very far into the platform itself (as they are selling the chips)
> 
> CAN anyone recommend some sites in this topic that do a bit of explaining or showing example code,etc?
> 
> All of this is highly appreciated.
> 
> (by the way, didnt someone on here make a multiple operator synth this year using DSpics? or an ARM?)
> 
> thanks
> 
> On Aug 9, 2010, at 9:39 AM, Tom Wiltshire wrote:
> 
>> 
>> On 9 Aug 2010, at 13:37, dan snazelle wrote:
>> 
>>> 
>>> "Regarding the generation of analog signals, you have plenty of options:
>>> - PWM on a digital pin (no external component needed except maybe a RC filter)"
>>> 
>>> am i mistaken in thinking that you cant use the PWM outputs for final audio signals (sine waves, white noise,etc)?or is there a simple way to convert this signal (isnt pwm a square wave output with changing duty cycle?)
>> 
>> Other people have dealt with exactly how this works. I'd just like to add that with a small 8-bit uP, you're unlikely to get a PWM frequency that can produce high audio frequencies at more than about 8-bit, tops.
>> You need a minimum 50KHz PWM frequency for full-range audio, and that implies a counter frequency of 12.8MHz at 8-bits resolution. Perhaps an AVR can do this, but the PICs use a counter rate that is a quarter of the master clock, and that implies a 5MHz maximum. Even if the AVR can do it, it's still only 8-bit audio - so think early 80s video games, not CD quality.
>> 
>>> ALSO...beyond the classic hal chamberlin book, are there any really good books on using AVR's or PICS for music/audio applications? OR just good books on modern AVR's or PICS?
>> 
>> If there are, I haven't found them. In fact, most of the PIC books I've seen are dreadful and have hideous examples of what I'd regard as extremely poor programming practice.
>> 
>> T.
>> 
>> 
>