Set BRD_BOOT_DELAY so the cube boots up at about the same time as the HL air unit
I think is for the Herelink developer or manufactuer to suggest the number and the working proven steps.
I dont have a HereLink myself, but apart from that I’ve never had an issue with following the normal All-At-Once ESC Calibration procedure in the Ardupilot docs.
BRD_BOOT_DELAY is a perfectly standard parameter you can modify yourself to experiment - it’s specifically there to allow for other devices that can take a relatively long time to boot, such as some CAN devices, and where those devices should be booted before the FC.
After the FC receives power, it waits for BRD_BOOT_DELAY milliseconds then completes startup. There’s no other affects after that.
So if your HereLink air unit takes about 2 seconds to boot up, set BRD_BOOT_DELAY,2000 so the FC comes online about the same time as the air unit.
Then your ESC calibration should be just like in the docs 
jesus man same here!!! did you solved finally?
That it did not work for me never…
I went to servo outputs and set one chanel to rctrough, then power off the esc by disconecting it from the PM board, then holding that chanel at its high pwm, then connect the esc, then put the pwm channel down i got that esc calibrated. I repeated this procedure for every ESC (4 ESC’s)