Dear ArduPilot Community,
I am encountering an ESC calibration and motor output issue on a Pixhawk flight controller running ArduCopter and would appreciate technical guidance.
Hardware Setup:
Flight Controller: Pixhawk
Firmware: ArduCopter (latest stable release)
Frame Type: Quad Multirotor
ESCs: 4 × Generic Yellow 30A PWM ESCs (all new)
Motors: Standard brushless motors
Calibration performed using Mission Planner
Problem Description: The ESCs do not calibrate correctly when attempting the standard “all-at-once” ESC calibration procedure. Motors do not initialize together and fail to respond afterward.
However, when ESCs are calibrated individually (connecting one ESC at a time), each ESC calibrates successfully and the motor spins normally during the process.
After completing calibration and rebooting the Pixhawk, motors still do not respond to throttle input even though arming succeeds.
Observed Behavior:
ESCs power normally and produce startup tones.
Group ESC calibration fails (ESCs do not synchronize).
Individual ESC calibration works for all ESCs.
After reboot, motors do not spin despite successful arming.
Receiver input is functioning correctly.
Issue persists after multiple calibration attempts.
Troubleshooting Already Performed:
Repeated ESC calibration attempts.
Individual ESC calibration confirmed working.
Verified SERVOx_FUNCTION motor assignments.
MOT_PWM_TYPE set to Normal PWM.
PWM range verified (1000–2000).
Power-up sequence variations tested.
Different batteries and wiring checked.
This suggests Pixhawk may not be outputting simultaneous PWM signals during group calibration or normal initialization.
Could this be related to PWM rail powering, output initialization timing, or safety state behavior?
Please advise what logs or parameters should be checked next to diagnose synchronized ESC output failure.
Thank you for your support.
Best regards,
Do they run using Mission Planners Motor Test? And you should have chosen some better quality ESC’s.
Sounds like you bought from this list
Hardware to avoid
Do they all have the 5v (centre) supply wire connected? If so disconnect/terminate all but one of them. If all connected together they’ve been known to cause issues as the voltage regulators fight with each other.
You can leave just one connected in case you want to power something from the servo rail.
Those ESCs are probably running Simonk which is vintage.
Those escs are made with the cheapest comps and its better to get new ones as Dave suggested.
I have a pile of them which failed due to some or the other reason.
run motor test as suggested by @dkemxr or maybe use throttle from rc to calib and min/max set to 0 to use rc tx endpoints as motor endpoints.
Motor test can also be used one-by one by just connecting one esc to a port at a time, before writing the output to 100%. then connect esc and it will enter calib mode.