Introduction to PX4 firmware
1. Basic concept [1-2]: Operating system: NuttX PX4FMU (STM32F427): 主處理器 PX4IO (STM32F100): 協處理器 (Code: Firmware/src/modules/px4iofirmware) *PX4IO firmware is automatically wrote by the PX4FMU Bootloader: PX4FMU, PX4IO 啟動前會運行的程式(初始化) The processing entrance of PX4 flight controller after the bootloader: Firmware/ROMFS/px4fmu_common/init.d/ rcS (啟動腳本: 指定想要啟動那些模組，如果有定義的模組，在rcS中start即可使用) 2. Some of important folder for development Src: we can find all source code here. Src/Drivers: including all sensors' driver. Src/Exmaples: including some simple examples for developers. ( Good one for beginner: px4_simple_app ) Src/ Modules : the core of px4, including all modules used in the flight controller. Src/Systemcmds: including all commands for flight controller. Mavlink: we can modify and add mavlink message here. (mavlink topic are messages passed from GCS or companion computer to px4) Cmake/configs: Including various compiling scripts for compiling on di