Both 8 channels PPM encoder and 8 channels revicer are required.
Before launch px4, ppmdeocde programe should be launched.
To download ppmdecode programe,
visit https://github.com/crossa/raspberry-pi-px4firmware.
Pxfmini and navio are not popular autopilot hardware in china,
I can handly to purchase it.
So that I use raspberry pi to build autopilot separately.
This dirver help us to decode ppm single to pwm and pushlish it
