Progress... More tinkering... mixed with a little insanity LOL
Top to bottom on the display...
Analog 1 voltage (translated from count), 490Hz PWM -> 100K/0.01uF
Analog 2 voltage (despite the "A" LOL), 31.25kHz PWM -> 100K/0.01uF
Laptop exhaust at distance, in deg C
% calculated PWM duty
Output "count" (0-255)
Calculated voltage that should be seen by the inputs
Don't let #1 fool you, that's a shaky and flailing little joker, I snapped the pic at just the right moment, wink wink
#2 is rock solid and follows the calculated around like a puppy, consistently lagging by 0.03V (it was almost certainly updating when the pic was snapped lol)
Guess which one is gonna do Vfb and which one is gonna do Fan?
Lots of tail chasing during today's adventures but I'm happy to report, despite all the voodoo, no magic smoke was released and it's functioning as expected for its current state.
Good stopping point... I'm learning...
Steve