Setup R9M Module and R9 Mini Receiver in Betaflight

This tutorial explains how to setup the R9M TX module and R9 Mini receiver in Betaflight. The R9M is a long range module that operates on 900MHz band. It’s compatible with most Frsky’s radios including the Taranis X9D-Plus, QX7 and Horus X10.

Don’t know what to choose between R9M and Crossfire?

Table of Content

What to Buy?

R9M TX Modules

R9M Module R9M-Lite Module
– Full Size JR Module
– Max Power up to 1W
– Designed Specifically for the X-Lite
– Max Power up to 100mW
– Lighter and smaller
Banggood | GetFPV | Amazon HorusRC | Banggood | RDQ

TX Module Antennas

900MHz Duct Antenna Super 8 Antenna
Cheap and robust Slightly higher gain (3dB), lighter and smaller; Tuned at 900MHz and meant to be used for both 868MHz and 915MHz
HorusRC | Banggood Banggood | HorusRC | Amazon
TBS Diamond
Just a different option to the Frsky Super-8. But it’s bigger and more expensive. Made to be used on both 868MHz and 915MHz.
RMRC | GetFPV| Amazon

R9 Series Receivers

R9 Receiver R9MM / Mini
Robust, servo connectors, MMCX diversity antennas The lightest and smallest R9 series receiver
RMRC | Banggood Amazon | Banggood | HorusRC
R9 Slim R9 Slim+
Just as good as the R9 but slimmer. Basically R9 Slim with diversity antennas
Amazon HorusRC | GetFPV

R9MM Receiver Antennas

Loose Antenna Dipole T Antenna
Cheap, Simple, Lightweight, and Flexible mounting More durable thanks to the plastic tube
HorusRC | Banggood 915MHz: BanggoodHorusRC
868MHz: Banggood

R9 Mini vs. R9MM

Frsky released a new receiver, R9MM. It’s basically the R9 Mini, with the “SBUS_IN” pin replaced with the “Inverted S.Port” pin.

It’s the go-to RX for F4 flight controller users, because you don’t have to worry about signal inversion anymore. For F3 and F7 users it really doesn’t make a difference.

Not sure what I am talking about here? See this post “inverted SBUS and SmartPort signals“.

Which receiver do I have?

I have both R9MM and R9 Mini receivers in the same pile, and they look identical! Here is a little trick to tell them apart.

The only difference I can see from the outside, is the silkscreen. The R9MM has a recognizable letter “S” on the Inverted S.Port, while the R9 Mini doesn’t.

Update OpenTX

It’s best to update OpenTX on your Taranis before using the R9M module.

Especially if you want to use the “FLEX” firmware, you have to use OpenTX version 2.2.3 or newer. For instructions: Tutorial: Flash OpenTX (2.2) firmware to Taranis

If you do decide to flash the “FLEX” firmware, make sure to select build option “FLEXR9M” before downloading firmware.

Update R9M Module Firmware

Download the latest R9M Module firmware here: https://www.frsky-rc.com/r9m/

Which Firmware Should I Use?

There are the Normal firmware, and the new Flex firmware.

The Flex firmware offers the following benefits.

You can switch frequency in the radio setting between FCC (915MHz) and EU-LBT (868MHz). It can be a pain with the normal firmware as you are locked to a specific frequency, and it requires re-flashing if you want to change it. Not that you will need to do that normally, but it’s just convenient, say if you travel to another country with your quad.

It also allows maximum power up to 1W, and now you get telemetry on all power levels, that’s probably the best feature.

I can see Flex firmware taking over in the future, but it’s still kind of experimental as far as I know. There were some complaints about failsafe in the past and Frsky has since released a number of updates to improve reliability. Anyway use it at your own risk.

Copy Firmware File to SD Card

Unzip the file you just downloaded, and the firmware file should have .frk file extension.

Put the firmware file on the SD inside the Taranis, inside the folder “Firmware”. Create one if it’s not there.

Firmware Flashing

In your Taranis, go to Radio Setup (long press the Menu button). Press Page button once to go to the SD Card page, and find the folder “Firmware”.

You should see the firmware file you just copied here.

Hold down the Enter button, you should get a list of options, choose “Flash Ext. Module

Pro Tip: DON’T select “Flash internal module”, your 2.4GHz will stop working! If unfortunately you did this, you can fix this by “Flash internal” using firmware for XJT module.

The flashing will begin, and the screen should say “Writing…”… The R9M module LED will flash Green and Red rapidly during this. It will take a minute or two.

Update Receiver Firmware

Download the latest R9MM receiver firmware here: https://www.frsky-rc.com/r9-mm/

Follow this guide on how to flash Frsky Receiver Firmware.

Note: FPort firmware allows you to use FPort, instead of SBUS and SmartPort. Don’t flash the FPort firmware if you want to use SBUS!

Taranis Setup

  • On your Taranis, go to Model Setup page
  • Turn OFF “Internal RF Mode
  • Under External RF, Mode, Choose R9M

According to your region, select FCC / 915MHz or EU-BLT / 868MHz.

You can also change the power level here: 10mW, 100mW, 500mW and 1W (Auto). The high the power, the less battery life you will get. Remember, the range is only double as power is increased 4 times in theory. And when using 1W power you should plug in an external 2S LiPo at the back of the module.

For the R9M Lite module, you might see higher power options in the menu, but this module is only rated for maximum 100mW. Setting it to higher power won’t do anything. So don’t get too excited.

Finally, set Failsafe to your desired option, I prefer “No Pulse” as explained in this post

Current draws vs. output power:

  • Taranis internal module 120mA
  • R9M 10mW 170mA
  • R9M 100mW 210mA
  • R9M 500mW 320mA
  • R9M 1W 370mA (without external battery)

Receiver and FC Connection

The wiring depends on whether you want to use SBUS or FPort protocols. I personally prefer FPort because it’s simpler to setup.

For FPort connection, there are only 3 wires:

  • 5V to 5V
  • GND to GND
  • TX pin of a spare UART on the FC to the S.Port pin on the Receiver

Please see my tutorial how to setup FPort for more detail.

Connection Example with Kakute F7

For SBUS and SmartPort, here is the connection. If you don’t know how to setup SBUS and SmartPort, please follow this tutorial.

Mounting RX Antenna

For the stock loose antenna on the R9MM, I just use two pieces of zip tie wrapped around the arm, and secured by heatshrink tubes.

For the Dipole T antenna, here is how I do it with two zip ties.

Check this more detailed guide to learn the different ways of mounting your 900MHz antenna.

Display RSSI in OSD

One cool thing about FPort is that RSSI works automatically! But make sure you first check RSSI in the OSD. Enable RSSI value element in the OSD tab.

On the bench it should read around 90 to 100. If it shows below 50, then you need to change the scale to 200%. As far as I know, this bug only affects R9MM using FPort, but check first anyway.

set rssi_scale = 200
save

 

If you are running SBUS, follow this tutorial to setup RSSI and display it in Betaflight OSD.

Edit History

  • Oct 2018 – Article created
  • Feb 2019 – Updated product, instructions and info about Flex firmware

40 thoughts on “Setup R9M Module and R9 Mini Receiver in Betaflight

  1. KİngNothing

    Same Problem with @Jason Bond

    I have tried, Flex and Non-Flex Firmware with both SBUS and FPort versions… I tried 3 different FC with 3 different R9MM receivers…

    For F-Port do you connect inverted s.port to TX? it shows like that in the image above… but i guess you have to connect S.Port/F.Port pad to the TX

    Only thing i can come up with is that the R9M modules we have are from a faulty batch… I ordered it from AliExpress and i can not open a dispute since 15 days has passed… Any suggestions?

    Reply
  2. levent oktay

    hi Oscar and friends,
    i want to change r9 mini pwm channel.
    default pwm channel ch1 ch2 ch3 ch4 but i use sbus İNAV for plane. i need more servo channel to 5 6 7 8.
    But default pwm channel TAER same channel. what can i do

    Reply
  3. GILLIS HAASNOOT

    Hi.
    For the r9 slim (+) you have to use the rx output for an inverted sport/fport signal.
    the tx is for inverted sbus.
    So if you have a flight controller without inverted uarts like the matek f405 or f411, you can use the tx or rx outputs on the slim receiver. This only works with latest firmware.

    Reply
  4. ES FLY

    i Have the same problem with @Jason Bond ,

    I try to bind the R9M to the R9MM it will bind and the r9mm light turns green and the radio confirms telemetry is established…then after about 10 seconds the green light on the receiver turns red and the radio confirms by saying “telemetry lost”…and it won’t reconnect automatically. When I unplug the quad battery and turn off the radio and then plug in the quad/turn on the radio, the receiver will not automatically reconnect to the radio.

    How to solving this problem?

    Reply
    1. Oscar Post author

      Check you are using the right firmware on both R9M module and R9MM receiver. Flash them again if you are not sure.
      Make sure you are using the correct frequency as well (915MHz vs. 868MHz) using the wrong one will result in very bad reception.
      Also verify if you have the correct antennas for the frequency you are using, the antenna lengths are different for the two frequencies.
      If nothing help it can be a hardware issue and I think you should escalate that to Frsky Customer Support.

      Reply
  5. Lowki

    Hi Oscar, great article as usual, helped me a lot, thank you!

    My radio discovers new sensors, betaflight’s ones, like AccX or VFAS, but every values read 0?
    Any idea why?

    Reply
  6. Jamie

    Hello there
    I have a little problem , i hope you could help me with.
    While working on it, i destroyed accidently the S port.
    And now i was looking for circuit diagram of frsky r9 mini so i can make a bridge connection for it.
    Do you have a circuit diagram of it ? if not where can i find it , cause i was searching the whole day on google and i couldnt find one.
    Looking forward to your answer.

    Best regards
    Jamie

    Reply
  7. Stephen Douglas

    Your instructions are great! I am setting up R9MM Rx with R9M Lite and using an OMNIBUS F4 FC. I got the Rx to bind and have stick response in the receiver tab in Betaflight. Problem is after about 1 minute, I get “telemetry lost” and the signal drops entirely. This is repeatable – no changes in reception environment TX sitting on table next to the RX but after about 1min the signal drops and I have to reboot the FC to get the signal back. I have the latest firmware flashed on Rx and R9 module. I’m running betaflight 4.0 on the FC.

    Any ideas ?

    Thanks !

    Reply
    1. Oscar Post author

      Do you have a different receiver? And can you try to connect the very same receiver on a different quad?
      I have a feeling it could be the power to the receiver, or just faulty receiver.

      Reply
  8. nordicblue

    Thanks for this article. Took my new Source One/Helio Spring build out today, with R9MM running F. Port, and thought something was wrong with hitting 33 RSSI in OSD. Little did I know that it was actually 66…lol.

    Reply
  9. Jason Bond

    I’m still trying to get my r9 system set up but am still having problems. One thing the frsky people told me that I haven’t seen discussed anywhere else is that you have to update the internal XJT module in the radio with the newest (may, 2017) corresponding XJT firmware as well.

    Anyway, in addition to power, ground, and sbus, I have wired the non-inverted r9mm s.port pad wired to an unused (non-inverted) uart on an f4 FC. I flashed the most recent (feb, 2019) standard (non flex, non fport) TX r9M firmware to the module and the corresponding (Feb, 2019) standard (non flex, non f-port) RX firmware to my r9mm receiver. The first time I try to bind the TX to the RX it will bind and the r9mm light turns green and the radio confirms telemetry is established…then after about 10 seconds the green light on the receiver turns red and the radio confirms by saying “telemetry lost”…and it won’t reconnect automatically. When I unplug the quad battery and turn off the radio and then plug in the quad/turn on the radio, the receiver will not automatically reconnect to the radio. Only if I re-bind the receiver to the radio will it connect again, but then the same problem repeats itself. Any ideas? Thanks for any suggestions…

    Reply
  10. Winfried Rijssenbeek

    Dear Oscar, always interesting to see your info. We were just considering purchasing this system. Is it allowed in EU (power and frequency wise) and what is the distance you can reach in open field with the “power” antennas? We would plan to stream the video from the drone to the tablet operating the drone. Hope to hear, Winfried

    Reply
  11. Piero

    Hi Oscar i have an issue charging R9M Flex firmware on ma X9D+. Both bootloader and Radio Firmware was updated to 2.2.4.N692 succesfully but when i try to select Internal RF OF and then go to External RF i can’t see no one selection beyond OFF. I’can’t select R9M from External RF Menu !

    Reply
  12. Andy Vines

    Hi Oscar, just setting up my R9MM with Taranis QX7S and noticed that only the lowest power setting has a telemetry option during binding. I’m using the latest version of Flex on both TX and RX. I thought I had read that telemetry is available on all power levels with Flex? Or is that just for FCC and not EU (I’m in the UK)?

    Reply
  13. VINCENT

    Hi Oscar,

    So for me, nothing is working well… If you can take the time to read what is below:

    My stuff: FC Xrotor (G4 F2) from hobbywing – This is an Omnibus F4 SD card Flasher yesterday with the latest firmaware..And BETAFLIGHT
    Rx: TARANIS XLITEVersion 2.2.3 + R9lite / TX Receiver R9MINI (the problem .. ;-() under open TX
    Flashing in Flex firmware receiver & transmitter

    What I soldered: The SBUS receiver on the SBUS entry of my FC
    The S.PORT / F PORT on the STRIP LED input

    I created the SOFTSERIAL instead of the entry B06 (ex LED STRIP)

    In Betaflight: – I activated the softserial and set the SMARTPORT in the PORT tab
    – I activated TELEMETRIE in the CONFIGURATION tab.
    – I activated the AUX12 in the receiver tab as RSSI

    The obtained result: – OK stick movement
    – RSSI OK (very fluctuating but OK)
    – No telemetry on the radio even trying the “discovery of new sensors”.
    It’s my first TARANIS – Iike i said I’have the flex firmeware on my external module and now i can just choose on FCC (100mw) or EU (not EU LBT) 25mw 8ch… Is it normal ?

    Best Regards

    Reply
  14. Matty

    Hi,
    I am getting really low ranges using the R9M and R9MM receiver. whenever I reach around 200-300m the link failsafes …. I exchanges antenna but did not help …. does the scaling of the RSSI have an effect on the failsafe mechanism ? it seems that the scale of 200 in Betaflight does not work and it should be 100? what determines this scale ? can a wrong scale cause failsafe earlier or later then required ? does the FC failsafe act on the received RSSI ?
    I am very frustrated …. I moved from the solid r-xsr that was perfect for my need but wanted a little more range …. (R-xsr never failesafed for me) and since I installed the R9M it just doesn’t work good….I can finish one flight without my quad falling out of the sky when its 200-300m away …… any advice would be great ….. was thinking maybe I should move to crossfire …. is it more mature ?
    Thanks
    Matty

    Reply
    1. Oscar Post author

      Where are you based? Are you using the right frequency for your region?
      Are you using the correct antennas for the frequency?
      How do you mount the antenna? Double check the antenna connectors are solid in both receiver and transmitter?
      Would be easier to join our forum for troubleshooting:
      Intofpv.com

      Reply
      1. Matty

        Hi Oscar,
        I am based in the US and am using (As far as i know) the right antennas (Super 8 and T) and Freq (FCC), I am using Fport. will join the Forum :-)
        by the way your site amazing, so informative and useful.
        Matty

      2. Oscar Post author

        There are a few things you can check, I will make a separate post about troubleshooting in the future. For now we will give you advice on the forum if you start a thread. It’s easier for me to manage the frequent replies there than blog comments.

  15. Doug Loshbaugh

    Thanks for your excellent tutorials, including this one!

    I ordered the R9 MM directly from FrSky (R9M/R9MM promotional combo), and it has a carrot over the inverted S-Port pad, not an “S”. It looks like your photo of the R9Mini. I’m not sure this matters, since it appears there is one firmware download for both on the FrSky web site.

    I had a terrible time figuring out which firmware to download for both the R9M and the R9MM. The R9 and R9M-{ite firmwares e are listed together with no apparent labels, and to make things even more confusing the downloads for the R9M-Lite appear in the Download folder label “Ranger9”. It appears the only way to tell which one is correct is to download and check the file name afterwards. In the R9MM downloads, both receiver and transmitter firmwares are listed without clear labeling. I’m still not sure I picked the correct files. I wish FrSky would label them better!

    Reply
  16. Vincent

    Hello Oscar,

    Thank you so much for your Tutorial. So In my case i have A Xrotor G4 f2 and a R9mini. On this flight controler there is a SBUS pad . So i connect Sbus receiver on the Sbus FC and the Sport receiver to a TX 1 (for example) And after in Betaflight i activate SMARTPORT on UART 1?

    Reply
  17. Matty Robbins

    Hi Oscar, I am getting really low range when using the R9M + R9MM , I already changed antennas and receiver but still range in no more then 300m when the RSSI drops drastically. Any ideas?

    Reply
    1. Oscar Post author

      Using the right frequency? have you tried a different RX just in case?
      Please join IntoFPV.com for troubleshooting, thanks!

      Reply
  18. Adam Bowler

    Wait a sec…If i’m trying to use FPort on the R9mm I DON’T use the pin labeled “S.Port/F.Port” I’m supposed to use the one labeled “Inverted S.Port”?

    Reply
  19. Mindaugas

    Hi Oscar,

    it is OK with module (R9) if radio is powered from 3S lipo battery? because as I understand there only external module power supply recommendation to not use more than 2S lipo.

    Vin Voltage Range: 4V-12.6V
    External Power Supply: 4V~12V (2s Li-Battery is recommended )

    Reply
  20. Hessel Prochazka

    Hi Oscar,

    Kinda stuck here. Wired the S.Port pin on the Slim plus (with Fport firmware on it) to TX3 on my Kakute F7. With whatever CLI setting I use for serialrx_inverted I can’t get it to work.

    Telemetry to my taranis works fine.

    Any ideas?

    Reply
    1. Oscar Post author

      did you flash the right firmware (FCC/LBT)?
      since you are using the “inverted” signal with F7, both serial_inverted and serial_duplex should be on.

      Reply
  21. Andrea

    With KISS v2, how can I get the RSSI on OSD? I have matek hubosd8se and the RSSI pad connected to S-port of R9mini, but it doesn’t work.. Do you have any suggestion? Thanks

    Reply
  22. Stefan Näwe

    When talking about SmartPort I think you got it somehow reversed. The R9mm has two SmartPort *inputs* (normal/inverted) and the FC *writes* to one of them. Just my 0.02€…

    Reply
  23. Taproot

    Thank you Oscar.

    Can you do a review on antenna options to the reciever? I guess many have this setup, but is looking to upgrade rx antenna.

    Reply

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