With funding provided by Craft and Theory, the ArduPilot team recently added general purpose support to the serial 5 port, which used to be a dedicated debugging port. ArduPilot users can now use any serial equipment (MAVLink, rangefinder, FrSky telemetry) on serial 5, just like they would on any other serial port.
To activate the port in ArduPilot, simply set the SERIAL5_PROTOCOL parameter (e.g., by using Mission Planner) to match the equipment connected to the port.
To connect the equipment to the Pixhawk and Pixhawk 2 autopilots, follow the diagrams below:
Craft and Theory just released a single pins telemetry cable that enables FrSky telemetry on the Pixhawk 2 serial 5 port. This telemetry cable can also be used to enable FrSky telemetry on a variety of other autopilots, including the Dropix.
Link to single pins cable.
FrSky telemetry provides the pilot with vital information directly on the RC transmitter, including flight modes, battery voltage, etc. Here’s an example.