Never too smart to make a dumb mistake...

A project log for Tiny CAN Positioning Motor Controller

A 12A/28V DC brush motor controller with position feedback that speaks CAN-BUS... in one square inch.

Pierce NicholsPierce Nichols 09/01/2018 at 17:190 Comments

I got the boards back from OSHPark's swift service... and discovered that I had made a dumb mistake. I used someone else's QFN-20 footprint (because lazy/in a hurry/etc) and discovered that it is entirely the wrong size. So this spin of boards is junk... luckily it's only $10 (one of the advantages of the limits of this contest) so I'm mostly just out the time. I also found that I'd forgotten to order the resonators, so there's that too. I guess next weekend is going to be a bit of a sprint; luckily OSHPark will be able to get me boards in time.

However, this gives me the opportunity to revisit an earlier issue, which is adding external logic to give me a nice pulse on each encoder transition. Turns out I can find places for the parts, and since I need to order both boards and parts already, it's an easy decision to make. New pictures and board files will go up tonight or tomorrow.