[sdiy] PWM, Vactrols & Opto-Isolators

[Jason Proctor]

ymmv, but i gave up on the pwm output option and use an SPI DAC 
instead (TLV5618). straightforward to use and works like a champ.

code and circuits etc in the files section of arduino_synth @yahoo.



>The application is a mix of my own interest and that I've noticed many
>of these inexpensive micro controller boards have many PWM outs. I'd
>like to be able to do digital control of analog circuits. It seems my
>best bet maybe some kind of DAC though, right?
>
>dustin
>
>On Wed, Jan 13, 2010 at 5:37 PM, Tom Wiltshire <tom at electricdruid.net> wrote:
>>  Dustin,
>>
>>  If you're looking to get a DC level out, then I'd say, yes, 30KHz is high.
>>  You could set the RC filter frequency for 10Hz and the pulses would be more
>>  than 3 decades above the cutoff, which ought to give a decent filtering
>>  action even with such a simple layout.
>>
>>  Jay's comment's about linearity are very pertinent though. PWM->LED
>>  linearity isn't going to be perfect, and LED->LDR linearity will add it's
>>  own twist too. How accurate do you need it? What's the application?
>>
>>  Regards,
>>  Tom
>>
>>
>>  On 13 Jan 2010, at 19:03, Dustin Withers wrote:
>>
>>>  Tom,
>>>
>>>  Is a pulse frequency of 30Khz considered high?
>>>
>>>  Thanks for the help,
>>>  -dustin
>>
>>
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