Community Forum

Choosing RC receiver

(Igor Vereninov) #11

@docwelch Even though this is possible from software perspective due to methods that we use for signal decoding only PPM is currently supported, Sbus creates significant load. We are performing optimizations and would probably overcome this in the future.

(Jiro Hattori) #12

Navio+ could not recognized FrSky TFR4 -B.
CH3 and CH4 are connected by a jumper, CH1 will output CPPM and CH2 will output RSSI (PWM). However, APM could not recognized connection of receiver by CPPM. (APM tentatively recognize receiver and saved calibration data when I hocked CH2 of TFR4-B: no way to use )

This TFR4-B has been used with Pixhawk.
Should it better to get FrSky S-BUS to CPPM decoder ?

Two more things to clear before fly my Navio+ ;-p

(Igor Vereninov) #13


Please note that servo rail and thus RC Receiver is not powered from the power module. Have you provided power to the receiver?

(Jiro Hattori) #14

Yes, sure.
5V supplied on Navio+ servo rail from SBEC.

(Jiro Hattori) #15

Now, I found a possibility of an issue that APM Planner is not compatible to ArduCopter running Navio+ and Raspberry Pi 2.
Navio+ can be R/C calibration on Mission Planner 1.3.16.

(Tony Wall) #16

Maybe you could add that (not powered RC port) to the docs explicitly. I presumed it was like the Pixhawk and the RC (“PPM” on Navio) connector would provide power. The first time it tells the user to use a separate power input is under the “RC output” section (servos) which comes after “RC input”. Not a problem for me because I’m using the HKPilot32 PDB, but it could delay other users who don’t know they need a separate supply/BEC for the receiver (Opto ESCs are quite popular so you cannot assume a BEC is usually available).

(Mikhail) #17

Good point, info added.
I’d also like to remind that our docs can be edited on Github. Adding anything is easy - just open the document and press edit, pull request will be created automatically.

(César Vargas) #18

Hey @ivereninov, I want to buy a transmitter and a receiver… I was reading this post and now I have a good idea. But which one do you recommend and if is it budget friendly it will be great!

(Igor Vereninov) #19

Hey @CavP28!

FRsky Taranis seems to give the most bang per buck.

(César Vargas) #20

Explain me something… I have to buy the transmitter, the receiver and some decoder? Or there’s a kit that comes with all this together ?

(Igor Vereninov) #21

You would need a transmitter and a receiver with PPM output. As per our docs, here are some models:
For ACCST (most FrSky transmitters):

  • FrSky D4R-II 4ch 2.4Ghz ACCST Receiver
  • FrSKY V8R7-SP ACCST 7 Channel RX with composite PPM
  • FrSKY D8R-XP

(Nathan Belk) #22

Can you show me a picture of how this is done? I need to get power to my receiver and not quite sure how I go about doig this.

(Tony Wall) #23

Clear diagrams are in the documentation.


Take note that when multiple ESCs with power (traditional/non-“opto” ESCs) are connected, you must remove their power (but not ground) pins from all but one connector, i.e. you only inject one 5v power source along the rail else you will cause problems and potentially damage the Navio.

This may also help:

(Nathan Belk) #24


I realized after I asked how to do this that the reason my servo rail wasn’t getting power was because of the ESC’s I was using. The ones I’ve used before would provide power, but I was using the DJI ones which don’t.

Once I bought a BEC, I was able to get power easily enough.

(Roberto Mojica) #25

FrSky all the way, use the s.bus to cppm from FrSky. Taranis is what im using with a x8r and the cppm decoder. Best value for your money and is open source.

(Daniel Domit) #26

Hi @mikhailavkhimenia I have 2 recievers:

  • Hitec Aurora 9 2.4GHz A-FHSS
  • FrSky V8FR-II

Can you explain how to connect them to the navio please? I dont see any PPM outputs.


(Igor Vereninov) #27

Navio+ will accept PPM, and Navio2 PPM/S.bus so you will need to use a receiver with PPM output. Models that you have listed do not have any of that. You can get a PPM encoder or a different receiver.

(Tony Wall) #28

Great news here guys I can confirm, something not so obvious when looking at the product pages…

FrSky have released a firmware update for their X4R and X4R-SB compact digital telemetry capable receivers, enabling BOTH CCPM and SBUS side-by-side.

It’s just a firmware update (no special cable needed, just the usual one for flashing) with two pins shorted to enable the functionality. There is no need to switch on or off later then. Once enabled, PWM port 4 remains SBUS (no worries there), but port 1 changes to CPPM. If that was not enough, ports 2 and 3 are STILL available for direct separate use so you can have a total of 10 channels on Navio+ with this receiver!

Of course with Navio 2 this is not necessary as we now have SBUS native support. But this little receiver is now a great choice and if you already installed the SBUS to CPPM converter you can remove it after the update to simplify your wiring.

Just one point of caution, the new LBT firmware does not work with the old internal module firmware. So you also have to follow instructions (and make/get a special cable) to update the internal module of the Taranis.

Furthermore, there is another new receiver on the market from FrSky. The XSR receiver is basically an X4R-SB with the pin headers removed and a smaller (what looks like a DF13) connector in it’s place. It’s priced about 30 euro on Banggood excluding taxes and shipping so this is now THE best compact receiver for Navio in my opinion (it also has both SBUS and CPPM output on the cable!).

X4R-SB “LBT” firmware: http://www.frsky-rc.com/download/view.php?sort=&down=246&file=Firmware-X4R/X4RSB

Receiver upgrade instructions: http://www.frsky-rc.com/download/view.php?sort=&down=121&file=How%20To-S.Port%20Products

Taranis internal transmitter “LBT” firmware upgrade here: http://www.frsky-rc.com/download/view.php?sort=&down=232&file=Firmware-XJT

Transmitter upgrade instructions: http://www.frsky-rc.com/download/view.php?sort=&down=174&file=How-to%20built-in%20XJT%20upgrade

Flash tool used for both receiver and transmitter upgrades: http://www.frsky-rc.com/download/view.php?sort=Tool&down=115&file=Upgrade%20Lite-S.Port%20Telemetry

XSR product page here: http://www.frsky-rc.com/product/pro.php?pro_id=154

Example at Banggood here (currently pre-order): http://www.banggood.com/FrSky-XSR-2_4GHz-16CH-ACCST-Receiver-S-Bus-CPPM-Output-Support-X9D-X9E-X9DP-X12S-X-Series-p-1031481.html

450mm quad build
(Daniel Domit) #29

Ok Thanks! for the moment i am using a PS3 joystick :smile:

(Sebastian) #30

Actually you can flash the s.port devices with the Taranis directly, no special cables needed: