Ardupilot

Based on Arudino Proccessing Controls – Open Source Electronics Platform.
Senses environment by receiving inputs from sensors and affects surroundings by controlling actuators.

Also provides SITL (software in the loop) simulator.

NuttX (Gregory Nutt) RTOS (Real Time OS), as of 2019 part of ASF (Apache Software Foundation)
ChibiOS RTOS (Real Time OS), is used for older cards (F405-Wing, Omnibus F4 Pro and more)
CentOS (NVidia ???)
Debian 1995, (base for Ubunto, Tails and Mint)

Loading a bootloader with DFU (“Direct Firmware Update”) (STM32F4 series), allows loading a firmware (including a bootloader) over USB

Flight Controllers’ Firmware
Flush Firmware using STM32CubeProgrammer.
Customize using C and Python
Pyhton is used to allow hover and shot arround waypoint

Sensors: Airspeed Sensor, Barometer, Fuel / Power Flow / Smart Batattries, Signal Strength Video / RX Feedback, Telemetry, Giro, GPS, Compas
Devices: Engine, Servos, Camera, Lights, Buzzer, Landing Gear