Talk about an expensive meal. In building the prototype PCB to drive the system today I managed to put 12v through a 5v rail and fried three polulu stepper drivers ($15ea) and five rotation sensors ($20ea). I have backup polulus, so at least I can make the thing move.

The sensor makers have offered to make a version that's got over- and under-voltage protection. I won't be able to make that mistake a sixth time! While I wait for it to arrive, I'm going to start putting the bits that definitely work onto a PCB and put a copy of [gcodecncdemo](https://github.com/marginallyclever/gcodecncdemo) into the firmware. By the time the sensors arrive I hope to have IK code and a JAVA simulator working.

Edit: Chips weren't fried! At least 4 still pass testing and seem to work. Oh well, now I have lots of spares.