First Wheels Spin

With the right wire pairs identified, the drive system finally came together on the bench: both motors wired into the driver board’s screw terminals, a 12V battery feeding the motor side, and the Raspberry Pi powered separately so a motor stall or short couldn’t take the brain down with it.

The driver board has onboard test buttons — a nice sanity check that doesn’t require any code at all. Press a button, wheel spins. Both wheels checked out that way before a single line of motor-control software was tested, which turned out to be a good call later: when the software side hit a bug, already knowing the wiring was solid meant the search for the cause could skip hardware entirely and focus on timing in code.

One thing very deliberately not skipped: a fuse on the battery line. A bench test can get away with a direct connection for a few minutes. A robot that’s about to drive around unsupervised on a floor cannot.

Wheels spin. Next: teaching Jambu to decide when to spin them.