Common Problems and Solutions
Problem: The motor seems to drive smoothly as you increase throttle to that channel, but as you approach and reach full throttle on that channel, the motor starts to either stutter or stop completely.
Cause: The MOSFET driver uses a charge pump to drive the high-side MOSFETs, this charge pump requires that the PWM signal given to it has a low pulse. If this low pulse is too short or stops appearing, the charge pump will stop working and the high-side MOSFETs won't work. As throttle goes up, the length of the high period gets higher so the length of this low period gets lower.
Solution 1: There is a configuration item named pwm_deadtime that can be increased, increasing this item will make the low pulse period longer, and the motors will be more reliable at full throttle. (the default is 50, increasing it to 65 will help)
Solution 2: Edit the endpoints on the radio for those channels. If your radio is using % units, change it to use about +/- 96%. If your radio is using microsecond units, edit the range to +/- 499 microseconds (100% is 512 microseconds). On a EdgeTX radio, this means pressing the MDL or MODEL button, then using the PAGE> button to navigate to the OUTPUTS screen, then select the channel and edit it. See screenshots below:
Note: I do not want to change the default value in the firmware because a higher value for pwm_deadtime can lead to lower maximum performance. The charge pump uses capacitors, which can be wildly inconsistent due to manufacturing inconsistencies and temperature variation. I would much rather people use solution 2 so they don't actually lose any potential performance.