PWM loopback test

Schematic:

.-------------------.
|                   |
|                   |
|      pin_in=A0    )------------.
|                   |            |
|                   |     100k   |
|                   |     ___    |
|      pin_pwm=D9   )----|___|---o
|                   |            |
|                   |            |
|                   |           ---
|                   |           ---  100n
|                   |            |
|          GND      )------------'
|                   |
|                   |
'-------------------'

transfer error plot

ATmega88

(Source code, png, hires.png, pdf)

analog value time plot

ATmega88

(Source code, png, hires.png, pdf)