Community Forum

Passthrough FrSky telemetry not working on RP3/Navio2

(Patrick Bernard) #1


I’m using successfully the native passthrough FrSky telemetry on Pixhawk, Pixhack and PixRacer with my
Taranis X9E and the great C&T (Craft and Theory) FlightDeck script and I would love to use it on my Navio2,
unfortunately it does not work when the telemetry cable is connected to the Navio2 UART port.

Here is my setup:
Raspberry Pi 3, Navio 2, X9E, X8R, SmartPort telemetry cable
AC-3.5.0-rc2, MP 1.3.45, OpentTX 2.2.0-rc9, FlightDeck 3.0.5

SERIAL1_PROTOCOL set to 10 (FrSky SPort Passthrough)
SERIAL1_BAUD set to 57
-C /dev/ttyAMA0 (parameter to start the ArduCopter code)

My FlightDeck script is receiving some datas like the HUD and the battery capacity but nothing else,
furthermore the update is slower than normally so I guess it is a timing issue.

As the Navio2 UART is directly connected to the RPi GPIO port I believe it is not directly relative to Navio
but mostly to the ArduPilot to linux porting…

Is there anybody using the FrSky passthrough telemetry with Navio2 successfully, any hint on this ?


(Ricardo Maroquio) #2

I really want to see this working. Please, anyone from Emlid could help us with this!? I bought 8 Navio2 boards and I really would like to make FlightDeck work on them…

(NRC) #3

I have the Navio2 and RPI 3. My Frsky X9E will be arriving June 1st. It does come with the X6R which should work since it has an S-BUS. once the transmitter is bound with the receiver, I am planning to program my X9E with APM flight modes and so on… Also, i am in a situation where I need to mount 3 more cameras. I have just 1 (RPI camera).

anyways, once I get this on June 1st, I will know that weekend doing my telemetry tests and find out the issues you are facing with it. I shall look forward for a solution too.

(Robert B) #4

Dears no news? I bought 2 NAVIOS and 2 telemetry cables.

any help ?

(Tatiana Andreeva) #6

Hi Robert,

Could you please create a new topic with a detailed description of your issue? You can use this pattern for it.

(Robert B) #7

but the issue is Crystal clear in the beginning of the topic, with all the setup and description.

Summary: to the telemetry cable send information (like GPS, Batery,etc…) directly to Frsky radios the SERIAL1_PROTOCOL needs to be set to 10 (FrSky SPort Passthrough), with all flight controllers except Navio works very well.

My setup is the same @jetpathar Patrick Bernard.
sorry I don’t understand.

(Tatiana Andreeva) #8

Hi Robert,

Sorry for the delayed response.

We are still looking into the issue.

(Baumgartner) #9

ok, Thanks.


i have same problem…setup as 10 and nothing on the radio, using craft and theory kit (btw works fine on my pixhawk2)

(Baumgartner) #11

I have a Pix2 too, works fine.

(Víctor Florencio Pombo López) #12

any news?

(Patrick Bernard) #13

I posted this issue on April 2017 and I’m very surprised to see that it is still not fixed 17 months later…

As wrote Robert B the problem was crystal clear so I do not see any reason for Emlid asking to open a new topic for it, new AC releases did not change anything so prior detailed description is still valid.

The APM, Pixhawk and all their derivatives runing ArduPilot generic Arm microcontroller code are not concerned, the problem is obviously within the linux ported code, probably a timing issue in the UART routine, therefore all boards runing the linux ported like RPi, Erle-Brain or BeagleBonecode are concerned.

Althgough it is not coming from the Navio itself, I was hoping that Emlid or C&T would consider
it seriously by trying to fix it by themself or by posting on the linux developers forum, guys like Tridgell or Mackay would probaly fix it.

C&T claims they don’t have the resources to develop the support for linux boards and I personnally believe that Emlid is more involved and closer to the developers community than the end users to fix this.

BTW you can also see my old post on the C&T forum here (started on July 2016 !) where you will find some more details:

For now I’m less concerned than befaore as I’m flying with Pixhack controllers from CUAV using C&T scripts but I will come back soon to RPi3 & Navio2 and I strongly hope that this will be fixed at this time.

(Richard) #14

I hope this helps, it seems that the C&T telemetry cable is a signal inverter and maybe the issue here according to this https://discuss.ardupilot.org/t/some-soldering-required/27613 in this setup ardupilot is setup to use FrSky SPort Passthrough I cannot vouch for this solution as I have used a teensy 3.1 loaded with https://github.com/zs6buj/MavlinkToPassthru and this Telemetry script https://github.com/yaapu/FrskyTelemetryScript connected to the navio2 uart port running arducopter 3.6rc8 setup to pass mavlink messages to the teensy which in turn converts to frsky passthrough and works perfectly.

(Baumgartner) #15

Thanks, but the problem is the Navio serial protocol not the scripts on the radio.

for me , no need anymore.

(Tatiana Andreeva) #16

Hey there,

We are still investigating the issue. It appears to be not so obvious, so we need more time for it.


i am also still patiently awaiting this…

(Ericfowkes) #18

I purchased the edge with expectations that I could do something as basic as s.port telemetry like all the other autopilots can do. Super disappointed and can not recommend this autopilot to anyone without s.port telemetry working. Still waiting for this feature as well but it seems like all these posts are ignored based on what I’ve been reading.

(Richard) #19

Finally got it working, the problem as previously eluded too was timing.

this commit got it working for me however there are two previous commits that maybe needed which I used for debugging purposes.