Pixhawk 4 mini running both wifi and SIK-radio

Hi every one
I have the following set up

Pixhawk 4 mini.

A laptop running Qgroundcontrol station V1.9

The way I am using the Pixhawk is that I connect the Telem1 to the jetson TX2 and then via wifi to the laptop. I use ubunto 16.04 in the Jetson and also ROS.

I want to be able to connect qgroundcontrol station to the pixhawk 4 mini avoiding the Jetson TX2.

In other words, I would like to run JetsonTX2 as the main source and have a direct connection from pixhawk to the qgroundcontrol station directly as a safety.

Searching on the internet I found the SIK-Radio

Just wondering if it is possible to use both.

Thank you for your time :slightly_smiling_face:

That is possible. Qgroundcontrol will automatically switch to the other link if one of them disconnects.


Thank you for your answer,

I have connected the telemetry of the PixHawk to the Jetson, and then where to connect the telemetry radio on the Pixhawk?

How can I use both?

Thank you

You need to connect the jetson through USB and SiK Radio through Telem1 as Pixhawk Mini only has one Telem port.


Thank you for the answer,

Do you know a link or tutorial on how to connect the PH to Jetson over a USB?

I was thinking about configure UART&GPS input to be telemetry, is that possible.


for USB connection you just connect Pixhawk and Jetson and type in the USB Device that shows up in linux for the connection link. Should be a serial link on /dev/ttyACM0 or something similiar. There is not much documentation for that.

You can try to connect on GPS port, I have not tried it before however there is the parameter option for it. See: https://docs.px4.io/master/en/advanced_config/parameter_reference.html#mavlink


Thank you for the answer, however I do have few questions :slight_smile:

1.- If you take a look at the following link, the number 13 correspond to a USB, even though it does not look as a USB input. And, the number 12 correspond to a micro USB, this input shall not be used.

I guess the number 12 (USB) Pixhawk shall be connected to the USB of Jetson, right. And, in the sdcard/etc/extras.txt of the pixhawk I shall write something like this, right?

    mavlink  stop-all
    mavlink  start  -d /dev/ttyS1 -b 921600 -r 400 -m onboard

2.- Well, in order to change the input 2 of the PixHawk that correspond to UART&I2C B to a telemetry port. What shall I change in the Qgroundcontrol?. My best guess is to change MAV_0_CONFIG and then I have several options, like: UART 6, TELEM 1, TELEM 2, TELEM 3, TELEM/SERIAL 4. Which option to use?

Or maybe I am mistaken, how it shall be done in order to change UART&I2C B to a telemetry port.

Note: I am using MAV_1_CONFIG set to TELEMTRY2 for the pin 3 of the PIXHAWK that correspond to telemetry1



After reading and trying and your suggestions it was solved as follows.

In order to set the port UART&I2C B of the PixHawk to a telemetry4 port and the TELEM1 of the Pixhawk to telemetry1 for a radio transmitter.

The following was implemented:

1.- UART&I2C B to a telemetry4 for a companion computer like JetsonTX2

In the sdcard of the PixHawk, under the file sdcard/etc/extras.txt

mavlink stop-all
mavlink start -d /dev/ttyS3 -b 921600 -r 400 -m onboard
mavlink stream -d /dev/ttyS3 -s HIGHRES_IMU -r 300
mavlink stream -d /dev/ttyS3 -s ATTITUDE_QUATERNION -r 200
mavlink stream -d /dev/ttyS3 -s GLOBAL_POSITION_INT -r 200

Inspired of this site and this site

MAV_0_MODE Onboard
MAV_0_RATE 921600
SER_TEL4_BAUD 9216008N1

  1. TELEM1 of the Pixhawk to telemetry1

I have not tried yet but must be something similar to:

MAV_1_MODE Normal
MAV_1_RATE 57600

1 Like

Hi Daniel, its me again :slight_smile:

To summarize:

1- I am running successfully UART&I2C B to a telemetry4 for a companion computer as JetsonTX2

2.- I have setup in Qgroundcontrol the following for the Pixhawk TELEM1:
MAV_1_MODE Normal
MAV_1_RATE 120

3.- A set of Holybro telemetry radio was bought.

4.- I just connected one holybro radio to the TELEM1 of the Pixhawk 4 mini and the other holybro radio to the laptop where Qgroundcontrol station is installed.

The questions or issues are:

  1. In the QGC station I can not see any holybro connected radio.

  2. How can I verify that the radios are well connected by means of the QGC stations and it is interfacing with them in a proper manner.

  3. Since I am using the companion computer to send mavilink protocol over a wifi. How can I set up that the first priority is the wifi and in case the wifi connection is lost the radio takes place.

Thank you for your help :slight_smile:


Now the two radios are connected and working.

What I did was a simple thing.

In the sdcard/etc/extras.txt I have comment out everything so there is no communication between Telem4 and the Jetson. Then I power the pixhawk with one module connected and also the other module connected to the laptop where Qgroundcontrol station is running. Then communication is established, as it can be in the following picture

Also the green led must be solid and the red led must be blinking in both modules.

The only problem I have faced is that when I enable all the commands in the sdcard/etc/extras.txt the modules do not work just the communication between Telem4 and the Jetson.

Well, I do not know if this shall be like this, that when the drone is far away from the QGCS and loses connection over a wifi, then the telemetry modules will take place over the communication.

Should you not swap MAV_0_xxxx and MAV_1_xxxx around? Surely your radio to the GCS is connected to TELEM 1?