Experimentation shows PWM DAC is a decent alternative to using the linear resistor ladder for VRef adjustment. Wiring will be fairly straightforward, as shown in the example below:
Experimentation showed that the topology best suited to the frequency generated by the Arduino's PWM is by using a 10k resistor, and parallel 3.3uF and 10uF ceramic capacitors. 22uF introduced a resonance waveform, and 10uF did not sufficiently smooth out the ripples.
This is one part of the solution to https://github.com/pyr0ball/pyr0piezo/issues/1
Experimentation shows PWM DAC is a decent alternative to using the linear resistor ladder for VRef adjustment. Wiring will be fairly straightforward, as shown in the example below:![image](https://user-images.githubusercontent.com/8482805/52678017-110d8d00-2ee5-11e9-855b-768524916527.png)
Experimentation showed that the topology best suited to the frequency generated by the Arduino's PWM is by using a 10k resistor, and parallel 3.3uF and 10uF ceramic capacitors. 22uF introduced a resonance waveform, and 10uF did not sufficiently smooth out the ripples.