"Dear, thanks for your answer. I have tested the px4 stack, but I prefer the apm:copter ;) All works perfect on it, but the hott protocol will be nice to have for fly without pc radio.
Is there an option to load the hott-module on-the-fly to firmware…"

"Hey, I´m using apm:copter 3.3 rc7 and would test the "hott telemetry" function of my graupner rc.
The telemetry function is included and working on the px4firmware used by apm:copter, described here link.
But I could not enable this module on…"