Came across this great poster made by Jethro Hazelhurst which shows the pixhawk autopilot along with all the extra addons for a quadcopter. Its a great overview of all the parts and how to connect everyhting together on your quadcopter!
This is a fantastic poster for sure. But I wonder why he took this RX. As far as I remember…it does not support failsafe. Did they change this meanwhile ?
If you have a Turnigy 9X radio it would be best to upgrade the firmware to Open9x. But if you dont want to do that then you can still setup the failsafe for the Turnigy 9X. But in general I would use one of the Frsky modules with the Turnigy 9x.
However you can still set the ardupilot failsafe on the stock Turnigy 9X radio. You can also check its working properly on the mission planner.