With F.BUS both channel transmission and telemetry data are carried in a single wire. This makes wiring much easier and additionally, transmission is faster due to improved protocol design.
All recent FrSky receivers have support for F.BUS protocol.
Channel transmission, telemetry, integration and F.BUS sensors can work at the same time.
FrSky F.BUS is supported by Spirit Pro, Spirit 2 and Spirit GT units. Spirit GT does not require any special cable. Other units will require the FrSky integration cable that can be bought in our Spirit eshop.
1 Switching receiver F.BUS mode
First from all, it is needed to switch receiver to F.BUS. This can be possible directly in the Radio menu.
1.1 Downloading firmware
Some receivers will require to update firmware. It can be downloaded from FrSky web pages here.
1.2 Flashing firmware
1.2.1 With FrSky STK
Flashing can be done with a special USB dongle from FrSky called FrSky STK - S.PORT TOOL KIT.
Here you can find video how to perform the flashing process:
1.2.2 With radio
You can also flash receiver firmware through your radio. Please check the FrSky video here:
2 FrSky F.BUS Wiring
2.1 Spirit Pro, Spirit 2
To allow telemetry transmission the FrSky Integration cable must be modified. For this purpose you will need a servo' plastic plug (already included with the cable).
Modification of the longer end
- Use a needle to free-up the Red wire from the plastic.
- Then plug the Red wire from the middle to a separate servo plastic (at the signal position).
Please connect FrSky integration cable according the following photo. Orange and Brown wires must be connected to the RUD port. Red wire must be connected with AIL pin.
Please connect also a direct cable for powering the receiver to AUX2 port if possible - this cable is supplied with Spirit unit. Alternatively you can use a secondary BEC power cable to power the receiver. FrSky integration cable can't feed power to the receiver alone so without this, it can't work.
Please note F.BUS support for these units is available from firmware version 3.5.0.
2.2 Spirit GT
Please connect stright cable between S.PORT and RUD port of the Spirit GT unit. S.PORT is used for F.BUS protocol.
3 Spirit Settings configuration
Once wiring is done, please set FrSky F.BUS receiver type in the Spirit Settings. Then save the settings and repower the unit. From this moment everything should work.