I am trying to build my own flight controller hardware to run PX4, and would really like to integrate the RC receiver directly onto the circuit board. In my searches so far, I have not found any open hardware schematics for any RC receiver. Has anyone had any luck with this or know where I can find any resources? I am open to any of the protocols that PX4 supports, with a slight preference to DSMX Spektrum.
The only somewhat hopeful thing I have found is the Crazybee F3 All in One flight controller. (https://www.banggood.com/Happymodel-Crazybee-F3-Flight-Controller-4-IN-1-5A-1S-Blheli_S-ESC-Compatible-DSM2DSMX-Receiver-p-1357375.html?akmClientCountry=America&cur_warehouse=CN). They have different versions with built-in DSMX (Spektrum), FrSky, or FlySky. I know these flight controllers don’t run PX4, but the fact that they have integrated RC receivers is hopeful because if they can do it, I might be able to as well. But I have not been able to find any documentation on how to do this.
Any suggestions would be greatly appreciated.