Reverse Polarity

A quick update during AP testing. I was messing around with a gear motor I got a while back (and used before for the barn door tracker)...

...and destroyed the encoder. In preparation for another project, I was working on creating a controller to regulate the speed of the motor and how much the shaft rotates. (Closed-loop speed and position control)

Dead.

Despite remembering each other time I used the encoder to check the pin out on the datasheet, I decided it was fairly safe to assume that the red wire was for VCC, the two wires in the middle for the encoder outputs, and the last wire for GND.

Big mistake. Turns out the red wire was GND and what I thought was GND was VCC. Add that to no reverse polarity protection, and you get a dead encoder. Bad on my part for not checking the datasheet again, but why is the GND wire colored red!

At least I got the motor/encoder combo used for only $20, and I can still use the nice Globe motor and gearbox. I looked up how much the encoder was worth new, and it was ~$50! Those 500 PPR and signal filtering don't come cheap. Oh well.