In this tutorial you are going to learn how to set up the Frsky  XM RSSI, so you can predict  spontaneous fail-safes from your radio set up, in order to avoid losing or damaging your aircraft.

For the new pilots, the acronym of RSSI means “Received Signal Strength Indicator” measured in decibels (dB) between a transmitter paired to a receiver, a transmitter such as the FrSky Taranis QX-7 and a receiver such as an XM receiver.

Frsky XM RSSI Output

To get the RSSI in your Taranis is very simple. It is important to notice that an RSSI pad isn’t needed, but instead you just have to do correctly the bind with your XM receiver, and then, depending on the firmware of your XM, you can have the RSSI by the 8th or 16th channel or just don’t have it activated. But if you usually fly FPV models, you may want to get the Frsky XM RSSI in your OSD, so follow the guide in order to get it done correctly.

 First, solder up the ground, power and SBUS wires to the receiver and to the flight controller, no more wires are required to get the Frsky XM RSSI working. In the one hand, this receiver is quite easy to set up compared to some other receivers which in addition they need a specific wire for telemetry, but in the other hand, this receiver doesn't support any sensors as the other receivers do, although they are not used regularly by FPV pilots.

After that, and as mentioned before, to get the Frsky XM RSSI working you have to bind the receiver with your transmitter. For this, make a new model in the MODEL SELECTION tab in the MENU if you haven't already created one for your aircraft, then, select the model you just have created. Next, go to the setup tab, and choose D16 in the mode selection of the internal RF, and click on [Bnd] so that you hear the transmitter beeps.

Take in consideration that for external modules it is a bit different, for example for the XJT module, you will also have to select the D16 mode with the switches in the back side, and you will also have to select the D16 mode in the external RF on the transmitter, and once the module is powered on, hold the F/S button on it, and release it, and if the RED LED on the XJT module is flashing, it is prepared to bind.

Then, power on the receiver while holding the BIND button, it can be powered by a 5V power supply. And, as many other receivers, if the RED LED on it is flashing, and the GREEN LED is on, the receiver is bound. The last thing remaining is to exit the bind mode, so, turn off your receiver and turn it on again, with this, the binding process is successfully completed.

At this point, the last thing remaining is to set up the Frsky XM RSSI on betaflight which we are going to see how it is done right now.

Frsky XM RSSI on Betaflight

Now, it is time to configure the Frsky XM RSSI on Betaflight which is very simple.

  • Start by assigning the Serial RX in the Ports tab to the UART where you have soldered the SBUS signal receiver.
  • Next, in the configuration tab, select Serial Based Receiver – SBUS in the Receiver Mode and Serial Receiver Provider selections.
  • And to finish with it, in the RSSI Channel options of the Receiver tab, enable the channel which is intended for FrSky XM RSSI according to your receiver firmware, this channel has to be also settled as an auxiliar channel in your transmitter. If you have done everything right, you should be able to see in the Receiver tab that one of the Aux channels value is around 2000us and it goes up and down approximately around 10us when the receiver is near your transmitter.

If you want to go a step further, you can also set the FrSky XM RSSI on the OSD. To do this, activate OSD in other features selection, which is found in the configuration tab. Then, go to the OSD tab, and tick in which you prefer between RSSI dBm value or in RSSI value, this last one is the one that is usually used. In this tab you can also set a low RSSI alarm that always advise you whenever the RSSI value goes under the limit you have set.

You should remember that the first thing you have to do after any important modification to your aircraft is to do a test flight to prove that the system works properly.