I recently got a new driver board and burned a motor with it :D. I’ve used a code that worked with the previous driver, but with the new one it produces very high current flow through the motor.
The sketch only limits voltage on the BLDCMotor class (thus setting motor.voltage_limit = 0.3f). Should I set the voltage limit on the BLDCDriver3PWM class as well? What is the difference between the two?
Phase resistance of my motor is around 13 Ohm, so the current at 0.3V should be very little (perhaps not even moving anything :D), but I got around 24A resulted in a lot of smoke…
With this phase resistance and 0.3V it would be quite impossible to get 24A of current. So there is something wrong here. Either the phase resistance is much lower than you think (you can measure it with a multimeter), or what is probably more likely is that this new driver has an issue, maybe due to software or hardware, and you got a short circuit in the driver board…
To answer your actual question, the motor limit is in the D-Q coordinate space, where voltage can be positive or negative, while the driver limit acts on the positive only DC voltage. We have a page on it in the docs: