Many years ago I've developed this, but without smoothing . Then aren't computer ...

I think, that it's enugh to replace the comparators with ADC's (or one with multiplex) and modify the software.

With PWM it's better, but also difficulter and not simply to find. I didn't need it later and therefore can't effective help you aspecially by software ...

I need a little more time to analysing your links, when you'll change the circuits . The second circuit hasn't analog input and the LEDs are controlled only from µC.

I understand Russian too, but havn't a keyboard with cyrilic letters to answer.

Greetings