Hi all,

I just bought an FrSky Taranis for my quad copter and needed to get the Mavlink data up on the Taranis LCD telemetry display. So here is my solution using a Teensy3.1 as a converter between MavLink and the S.Port on FrSky X8R.

See attached file below...

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I will most definitely uset his feature as I like to know the usage of the battery as well.

Thanks for doing so.

Hi all

great work on this converter.

Just a small question. I was looking at the source code for Arducopter and in there there's a provision to run user code (UserCode.pde).

In the case of the PixHawk that exposes Serial 4 and 5 wouldn't it be easier to have the code running inside the PixHawk and just connecting one of these serial ports to the X8R ?

Might be a dumb question, but I'm just starting at this....


Answering  my own question, found on the NuttX source files an implementation of frsky telemetry output at the drivers/frsky_telemetry dir which at first sight appears to output to a serial port the telemetry data already packaged for the frsky. It appears it is started by command line with an argument defining the output uart.

Hi Luis,

I believe the frsky_telemetry app built into the PX4 firmware is for the old FrSky hub protocol, not the new SmartPort protocol. 

I was thinking about adding a new app for the SmartPort protocol as the software wouldn't be too difficult using the existing apps as a template. But I believe the problem is the UART on the Pixhawk doesn't support the inverted serial needed for the SmartPort protocol. I haven't had a chance to look into this further though.


Many thanks - I have now got the basic setup working with my 433 telemetry in parallel. What this means for me is that I can move on from mission based flights glued to the laptop to just flying around - this is backwards I know but I am a much better tech than pilot.

I will add the little snippets of code from the thread to expand the telemetry via my X8R and I am really interested in the LRS possibilities. I have a home made DTF UHF 1W TX and a couple of RX - not much opportunity for long range in Northern Germany but the tech is fascinating. Also many thanks to the contributors that have added to the quality of the thread.


Help needed!

Installed MavLink_FrSkySPort_1.3.zip

Cut trace, applied power to Teensy 3.1, installed Teensyduino, etc.

When I upload MavLink_FrSkySPort from examples, I get the following error: 

MavLink_FrSkySPort.ino:47:25: fatal error: GCS_MAVLink.h: No such file or directory
compilation terminated.

I can run other Teensy examples OK using Arduino IDE 1.0.5.  What am I missing?

It is on the 6th page of the thread:

It's simple...do like this:

1. Download and extract the MavLink_FrSkySPort_1.2.zip file   (for example. to your desktop)

2. Open Arduino software and in  menu File/Preference change the sketchbook location to the place you extracted the .zip file, press Ok

3. Restart Arduino and in the menu File/Sketchbook  select  MavLink_SkySPort

4. Compile and transfer to Teensy

( You must have installed the Teensy extension for Arduino  http://www.pjrc.com/teensy/td_download.html  )

I think that the real problem is that I used the Arduino IDE to install the library.  I manually moved MavLink_SkySPort to the proper location and the error went away.

Help needed again...

APM solid blue and red, X8R solid green, Taranis telemetry screen 1 set, Teensy loaded with Mavlink_FrSkySPort and solid orange, wired per instructions. USB trace cut, analog not connected.

Results: all zeros on telemetry screen.

Scope shows this on SPort signal line at 2 VDC per div.:

Question 1: Where do I start trouble shooting?  

Question 2: Teensy blinks 3 times at startup then goes solid orange. Is this normal?  If not, what is?

Question 3: Three other tabs open with Mavlink_FrSkySPort.  They are 'average', 'FrSkyPort.h' and 'FrSkySPort'.  How are        these to be used?

Any and all help would be appreciated!

Have you set up the Taranis to receive basic telemetry? That is, do you have a reading for A1 approximately 5 volts. This would confirm the basic telemetry without Teensie. (The X8R internal voltage divider for A1 is 4:1 so your range needs to be set to about 13.2 volts.)

Have you bound the X8R in D16 mode? I had a similar issue when in D8 mode. Download the X8R manual from FrSky if you don't already have it as a reference.

Have you connected Teensie TX and RX lines around the correct way? The Teensie blinks about 1 per second when first connected and then is either rapid flashing or solid when data is received. Swapped TX and RX will result in 1 per second with no solid or rapid flashing. You need the TX line to trigger the APM output unless you also have the 3DR telemetry system running in which case just the RX and ground are required.

Set up you Taranis telemetry pages as per the 2nd or 3rd page of this thread.

I made all the above errors but it's working now.

Thanks, Alan.  I had already done what you suggested but still no joy.  A1 = 4.75 and mode is D16 on Taranis.

Wiring is per instructions and I have solid orange LED on Teensy.  I do not have 3DR radio connected at this time.

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