External pwm ESC questions
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Hello,
I am working with a FETtec 45A 3-6S 4-in-1 ESC with the Voxl2 using the IO expansion board. I have gotten things setup where I can use QGC to control the motors using the actuator mode and it seems like I'm getting communication, however I am not sure if I am able to calibrate the ESCs. Whenever I run the px4-qshell command to calibrate esc I get an error that it times out, I hear beeps from the ESCs that seem to indicate its being calibrated but I'm not sure if it is actually working or not.
The issue it is causing at the moment that makes me unsure if they are calibrated or not is when I try to fly the drone either cannot get off the ground at all or one motor seems to be much lower power than the rest and it spins or flips. Makes it seem like something isn't
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@mkriesel First steps would be to verify that the correct propellers are installed, that all the propellers are spinning in the correct direction and that the motors are mapped correctly.
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@mkriesel , a few tips..
- I suspect FETtec ESC is using a pretty accurate xtal or accurate RC oscillator, so you should not need to calibrate the ESC
- You can check the current calibration by using QGC to control the individual motors to see at which command they start up and make sure that is very close to the same (typically around 1000us or a bit more)
- Additionally, you can spin up each motor with propeller at certain % power, lets say 20% or 30% and using an optical tachometer (RPM meter) to measure the speed of each motor
- Those are some sanity checks you can do without being able to calibrate and without having any ESC telemetry.
Regarding the ESC PWM range, the procedure is documented for VOXL2 IO board : https://docs.modalai.com/voxl2-io-user-guide/#how-to-perform-esc-calibration -- please go over that and make sure you did it correctly.
Alex
