Regardless of the ESC_Calibration param number (except the 0),
the FC blinks blue and red on startup indicating it is ready for esc calibration,
but then turns into yellow, green blinking and I am not able to calibrate the ESCs.
I dont know what to do at this point, and maybe someone has an Idea what could be done?
The blue and red on startup is probably the gyro calibration. The ESC calibration is normally blue, red and green although it can depend upon the flight controller.
It’s necessary to do the RC calibration once before the ESC calibration can be done. So maybe this is a new board and the RC calibration hasn’t been done yet?
The ESC calibration will also not work if the MOT_PWM_TYPE is set to "Brushed’… which is probably not relevant but just mentioning it anyway.