APM加载固件方法
https://www.xt-xinte.com/APM-2-8-RC-Multicopter-Flight-Controller-Board-with-Case-6M-GPS-Compass-for-DIY-FPV-RC-Drone-Multirotor-p134250.html
https://www.xt-xinte.com/APM2-8-APM-2-8-No-Build-in-Compass-Flight-Controller-Board-Bent-Pin-with-Case-for-DIY-FPV-RC-Drone-Multicopter-p168041.html