/diy/ - Do It Yourself

>>1608730
An arduino basically is a microcontroller, albeit a pretty inefficient one. Not that it isn't a good way of going about this project, but if you're apprehensive about using an arduino, I doubt you'd prefer using a barebones avr.
I'd use an R2R resistor ladder DAC which feeds a normal triangle wave comparator PWM circuit. No buffering needed either, since the output will be going into a high-impedance comparator anyhow. So that's like 2 ICs, assuming you make the triangle wave oscillator with the second comparator and your resistors are in a single-package network.