Talking to Rpi Companion Computer on Pixhawk 6 over Sik Radios

PX4 Autopilot Telemetry (Comms) 📡
1

Hi there,

My goal is to operate an autopilot drone via an Rpi companion computer. At this point I have been able to get MAVSDK-Python and mavsdk_server running on the Rpi. I have also made a telemetry connection between the Pixhawk 6 and a mavsdk_server running on my ground station computer, verified by QGC as well.

My question is, how do I move this server to the Rpi and communicate to it over the Sik telemetry radio? Meaning, how can I initiate the server and receive data from the Rpi through the telemetry connection to the pixhawk on the ground station? Is this possible to do without a wifi connection to the Rpi? (Sorry I’m a bit of a noob)

Many thanks

2

I would connect the RPi using an FTDI cable to the Pixhawk.

Have you seen these docs?

3

Thanks for the response Julian. Sorry I should’ve been more clear. I have the hardware all connected with the Pi connected to Telem 2, but I’m struggling to understand how I can send commands and receive data from the raspberry pi through the pixhawk telemetry connection with the ground station. Say I have a program written with MAVSDK-Python on the Pi, how would I go about running accessing this program remotely from the ground station through the telemetry mavlink connection? Essentially I’m wondering how I can communicate to the Pi on Telem2 using the ground station. Would this be done in Mavlink code on the ground station? Can it be done with the MAVSDK-Python Library?

4

I understand. Can you explain what sort of command that would be, so on a high level, what are you trying to achieve?

5

Ultimately we want to do a leader/follower algorithm with 3 drones. We want to send and receive GPS/RTK data, Hardware ID data and RSSI data from a LoRa module connected to an RPi on each drone. Each drone will be receiving all this data individually, the location data from QGC and the RSSI data from an on board Pi. We want to route this data from the two followers, through the QGC Sik telemetry connection, to the leader drone.

But for now our current hurdle in hardware dev is figuring out how to get data from an onboard RPi to the ground station over the telemetry connection when Mavsdk is being run on the RPi and not the ground station computer.

So, for a first step in hardware dev I would like to run takeoff_and_land.py on the RPi’s Mavsdk server and initiate this from the ground station.

6

So as a first step you probably just want to forward MAVLink traffic on the RPi. So that data from the drone goes to MAVSDK as well as the ground station.

You can do that using something like mavlink-router, or you can add multiple connections in MAVSDK and enable forwarding.