I went trough the schematics, BOM, the forum and the datasheets to better understand what the hell was going on.
on 12s you can kill vesc
It turns out that the VESC's BOM is not really aimed to accommodate 12s. Neither for testing nor use.
so all tests on 6s max
A assume you mean setup.
you need to check all solder check fets and in the end try to resolder drv
Did that twice, on 2 different days. I found a bridge in the USB pins, prior to actually upload the firmware, and fixed it.
What I actually did wrong was to not adjust the firmware for 0.5 mhom shunts. That could have fried the DRV8302. Adjusting the firmware or replacing the shunts with 1 mhom ones resulted in the same behaviour.
( every time i buy vesc i buy 2 pcs vescs and 10 pcs drv chips )
I think I'll go a bit further than that. I'll revise the BOM so it follows datasheet's recommendations for 12s.
My main concerns are now with:
1) the 50V ratings of many caps that should be higher rated: C39,C1,C8,C9,C40,C43,C44,C49,C37,C51,C2,C3,C27,C32...the list goes on.
2) The absence of a TVS on Vsupply
And beyond that I still have a lot of questions, like:
Why is C39 10u 50v and not 4.6uF + 0.1uF 100V?
Why are C28, 29, 30 220nF and not 100nF?
I'm going to have a lot of fun with the VESC.