Telemetry 3DR SikV2 doesn't connect to GCS Mission Planner

Hello world!

I’ve been stuck on this issue for several months now, and after ordering a new SikV2 radio, reinstalling Navio2, it still didn’t solve the problem.

Posted are screenshots of my settings.

Emlid Raspbian 4.19.83
ArduCopter 3.6

Cannot connect telemetry to Mission Planner or APMPlanner.
Telemetry kit connected via UART port on Navio2, both lights solid green:

Goes to “Trying to connect…”, times out, “No heartbeat packets received”
UDP works though, but if I want to bring it out to the field, telemetry to GCS would not work then.


Parameter settings (connected via UDP):

RealTerm serial input from my Windows 10 laptop, after entering ‘asdfasd’

  1. If using any additional hardware please provide exact make and model.
    Raspberry Pi Camera V2

If there is any more information you need to help figure this out, please let me know!

Thank you,

Hi Vegeta,

May I ask you to share a picture of your setup?

Have you tried connecting the telemetry module via a USB port? Does it work that way?

Also, can you check if your module appears in /dev/ folder after connection?

Just tried USB by TELEM2="-C /dev/ttyUSB0" and it did not work either.

cd /dev
ls -l serial*

Hi Vegeta,

According to your terminal output, it seems, that Raspberry detects the transceiver.

Can you also print the following command in the terminal after the connection:

dmesg | grep tty

Moreover, I’ve been trying to reproduce your setup lately. And I’ve experienced a missing driver issue for Windows 10. Does your Device Manager show any warnings?

Finally, two more questions. Is there no telemetry red LED’s light at all? And do you have a JST cable without 4th and 5th wires for CTS and RTS by any chance?

I’ve been using this driver for the radios. Let me know if that’s even the correct one.

Connected via USB:

Connected via UART:

Red LED’s flash. when I use screen on the Pi, and Realterm on PC, the garbled messages and red LED’s are in sync as I press/hold on my keyboard. I couldn’t figure how to make serial input readable though…

I do have a JST cable with female connector ends.


Hi Vegeta,

In the Mission Planner via UPD connection can you try changing the Serial1’s baud rate to 57? I guess, there’s a baud mismatch between your PC and a drone.

Holy moly, finally got it to work.

I changed Serial0 to 57, but that didn’t work alone.
I guessed on unchecking RTS CTS and Op Resend on the SiK Radio.

Why does changing Serial0(Telem1, UDP connection) work on fixing the telemetry radio(Serial1, Telem2)?

Thank you Mikhail for all your help!

Hi Vegeta,

Nice! Glad that you’ve solved that issue.

I believe, the issue was connected with a CTS and RTS wires (clear to send/request to send). As far as I know, there were issues with setting up a telemetry via radio when the CTS line is connected.

If you feel like experimenting, I’d love to know what was the catch exactly.