Do you have some pictures of your boards? How do you replace the DRV chips?
I tried to add some pictures on this post but it gave error when trying to send, and same when i tried to upload elsewhere and post link.
I tried to do some measuring on the board with wrong current measurement, i found that on R41 on DRV chip side is getting small voltage leaking from somewhere which explains the wrong current reporting. It also sometimes changes how much voltage there is, when the error was small i was able to run motor detection fine, but very soon after that it started giving DRV fault. Im really starting to feel like i have batch of bad DRV chips.
I have possibility to use hot air, but i desoldered few DRV chips with torch lighter when i didn’t want to wait to get access to hot air. I soldered most of them in place with soldering iron, which i feel like started going just fine after some practice. I did try soldering 1 with hot air but it left small balls of solder around the board so i just used soldering iron after that.
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The drv chips have a ground plate that needs to be connected, so its really essential to use hot air.
Thats not the problem, soldering it through hole on bottom of the board it connects no problem. On some first power on tests i had issues due to not properly soldered ground, but after finding proper way to do it, it has been fine.
Ah yes true, i forgot that there is a hole in the board for the gnd connection. Did you try the testing instructions for the FOC_KING controller, they are really complete and maybe you find out where exactly the problem is. But either way its probably a faulty connection to the drv chip.
Im not sure where to find those FOC_KING instructions, i found its github and thread in this forum.
Anyways, after replacing DRV chips, the board i drove for about 15km before issues, started working properly again. Now i also tested driving with FOC which seems to increase torque by good amount. Other board also spins motor fine, but it still had some weirdness with current reporting, and for some reason ADC is not working, so throttle does not work. The board i assembled first is still not working, nothing happens when running motor detection other than it shows motor current going up and down. I might just give up on this one and build one from fresh board, i’d be happy with 3 working FOCers.