BROWN: Power Pins
Green: Mandatory Pins
Blue: Used but can be relocated in code.
Green Text: not used but can be used.
Important Notice: you can use PPM instead of PWM. This will save you pins GPIO (6, 12, 13, 16, 19, 20, 21, 26) and only GPIO 5 is used in this case.
To Know how to setup for PPM please refer to this PR: https://github.com/HefnySco/ardupilot/tree/tip_ppm
