As a retired and frustrated engineer I have decided to build a homebrew quadcopter – not a racer -with a view, long term, to creating my own software for flight control and any other functions. The airframe is already built with four 2213 motors, and 1045 props, at 550mm diagonal distances being fed by four simonK 30k 2-3S ESCs. I have also have the new version Flysky FS-6S six channel digital Transmitter/controller and FS-iA6 Receiver on order.
Advice is needed on the choice of a suitable flight controller, compatible with the receiver and the ESCs – and which also meets these requirements - incorporates giro and inertial functions – is price sensitive – facilitates possible future inclusion of barometric and gps functions and also provides adequate information and backup to put the system into service. Any help would be appreciated please.
Hi
If your an engineer looking to ‘play’ and happy to spend time configuring, then it must be Pixhawk/APM for you 
Cheers
Steve
Yeah I agree, APM is a great platform, based off arduino, then as the ardupilot project reached the flash memory limits of the atmel CPU they moved to the pixhawk platform that uses a more powerful 32bit processor. So both a great places to start or get ideas for your own platform with APM boards being very affordable nowadays with plenty of documentation.
Agreed ! Pixhawk or APM in did.
For me the 2 best FC for soft and accurated flights with a lot of gadgets to assembler and the best : mission planner.