This one is pretty convoluted so I'm going to try and break it down.
Everything has been working great until this morning when I uploaded new code that had to do with the radio. After 30 seconds of motor movement, the Li-Po protection kicked in (probably short-circuit protection). I had to bypass the li-po circuit with a wire because I first thought the protection circuitry was being screwy (I was wrong). One of the four mosfets proceeded to let out the magic smoke, I cut the power (note that both half-bridges are driven high by default) . The mosfet was already welded to the copper so I couldn't desolder it, so I just forced it on again to see if it was over, but it just flamed up and took the other fet with it, and scorched my board.
SO I whipped up a new board (same PCB design) with the same components (literally) except for the driver of the exploding mosfet side. I hooked everything up except for the motors and everything looked fine on my scope, both motor channels seem to match in every way. I let it sit there and altered the PWM for a while, everything is fine. I hook up both motors and instantly the li-po protection kicks in, I bypass it, SAME mosfet smokes, I cut power, I get a little frustrated and bypass the protection circuit again, mosfet unleashes long red flame, PCB is scorched again.
Some recap:
- I checked the IO driving both mosfet channels with my scope and both are fine
- Everything works until a motor is connected to the bad channel
TLDR:
Only one mosfet keeps shooting out long red flames. It seems both sources of one (of four) of the complementary mosfets are latching together.
Any ideas?