[sdiy] PWM from a Micro as a CV source?

[Justin Owen]

Hey all,

I'm after some advice on using PWM-capable pins from a Micro (probably the ATMega168/Arduino, and possibly via a TLC5940 LED driver) as a CV source.

The oscillator I'm using at the moment has its Pitch and PWM controlled by two HF113 Optocouplers, each sitting in the negative feedback loop an Op-Amp to make the control linear, which is fed a control voltage - which at the moment is basically pots set up as voltage dividers.

I'd like to replace the pot/voltage dividers with PWM outputs from a Micro.

Are there any reasons why this shouldn't work?

Would I need a Low-Pass filter of some sort on the PWM output?

All the info I've seen says it will control LEDs just fine - so therefore it should drive an Optocoupler - just wanted to see if there were any problems I might not have thought of.

Thanks as always - J