|
The current is probably less than 0.1uA. You need 1M resistor to +12V and then AC coupling to op-amp, 100nF, so you have good gain for any PWM signal.
I've plenty of photodiodes/transistors, but unless you are visiting Limerick-Shannon, that's no use.
Some mice have a rotary encoder using IR LEDs and photo transistors, but maybe only old ones with a ball. Current ones might use a switched rotary encoder for the wheel that's also a middle button.
|