Re: HP printer encoders

I've stripped the bits out of many printers and have always wondered
about the HP encoders, it might be possible to work out which is the
light source by using the diode checker function of a multimeter, of
course you may get similar readings on other pins but you might strike
it lucky. Then tentatively apply voltage while measuring current,
observe the LED with a digital camera as these pick up IR which it may
well be.

After that, I guess you try what seems logical and compare the pin
layout to anything else you find. Considering the resolution of some
of these printers if you can hack the encoders they would be quite a
cheap solution as I'm always seeing HPs in dumpsters/skips.

Cheers,

Graham