I'm trying to build a full autopilot which would be controlled by an onboard RaspberryPI (probably Pi Zero W). The PI would initiate liftoff, mission/flight path and landing. Micromanagement should be done by controller. I'd expect the controller to:
provide telemetry / gps back to the PI
maintain certain height from the ground
perform obstacle avoidance using video/sonar ( so should accept sensor input) at least in one direction (preferably all around).
connect to PI using wires (preferably).
Support 4/6/8 - copters
Question is, which controllers are available to let me achieve this?