Well, the connectors didn’t turn up on Saturday, but they did turn up today! So after a bit of crimping, and a bit of soldering (and a few mistakes, but we won’t go into that) I had a couple of cables made up to allow me to connect the Q85 motors to the ODrive.
Here is one of the sets of cables. They consist of the red wires in the back that go to an MT60 connector that carries the main signal to the motors, and then another bunch of wires that come from the hall effect sensor that is embedded in the motor. This tells the controller where the motor is in its cycle, so that it knows which coils to energise.
Also needed were some capacitors across the sensor terminals to cut down on some noise. Instructions for doing this are here: https://discourse.odriverobotics.com/t/encoder-error-error-illegal-hall-state/1047/7
With all that in place, I gingerly powered it all up and set about calibrating everything. I followed a guide on the main astromech forum, along with the odrive guide for hoverboards (same principal as driving an astromech it seems). It took a bit of trial and error, that I’m hoping to iron out into a proper tutorial at some point, but the motors were eventually running!
The mixing that I’d done in software all looks like its working as intended. I can also bump the speed up incrementally, as I can with R2, but with a lot more control and accuracy.
I do need to change the ramping settings on this, which I may even make changeable on the fly from the controller. Also the multiplier may need some tuning to set top speed, but that will require some testing in situ. I need to push my changes back into github, and make sure that R2 still works with the new code.
I think this brings the electronics to a good resting place for now. Just going to tidy up some of the cabling and add a volt/current meter. Its time to concentrate on making the actual droid. So this weekend it will be time to don the breathing mask and start glueing everything together.
