[sdiy] frequency counter, DAC for demultiplexing

[Ingo Debus]

Am 25.10.2009 um 14:02 schrieb Tom Wiltshire:

>>>
>>>> A 8253/8254 counter chip can make minor wonders for you along  
>>>> with some processing. Found in several synths and at least one  
>>>> high end counter.
>>>
>>> Argh, why use such an ugly and outdated chip these days?
>>
>> Funny... I get almost the same feeling when someone wants to abuse  
>> audio DAC for multiple CV outputs ;)
>
> I wasn't trying to abuse it. I rather hoped it might work, as it  
> would have been a nice, simple solution. Unfortunately it didn't.  
> (Hey, just add it to the list...)
>
> I've been using the dsPIC Audio DAC for slow modulation for ages  
> with good results. You can get great envelopes and LFOs and random  
> modulation sources out of it, so it didn't seem too unlikely. It'll  
> produce a infinitely-held level ( e.g. outputs down to 0Hz) so it  
> isn't *just* for audio.
>
> The trouble is not the fact that it's intended for audio, but  
> rather that its Sigma-Delta, which rules the demultiplexing out.

I still think it's not entirely impossible. But probably you all are  
right, the performance would be so poor that it isn't worth the effort.
Perhaps better use a 8053 as DAC?? Ok, I'll stop now ;-)

Ingo