MAVLink Identifying AP radio link

[Hylke Faas]

Hi,

We are looking into the MAVLink interface (in combination with px4 AP firmware) and are playing around to build a custom (simplified) GCS.

MAVLink seems to support multiple AP connections over 1 telemetry device, therefor we are struggling to understand how we can identify the (remote) radio (telemetry) link used for one AP connection.

We are looking to "show" the link quality with a specific AP (I guess the remote RSSI status from the RADIO_STATUS message). 

However there is no RADIO_STATUS message being send with the SystemID of the AP, but only with a SystemID from the telemetry device (it is, as documented, probably injected into the link by the device it self). We also couldn't find any other reference how to identify the quality of the link or, for example, which radio SystemID is used for the connection with a specific AP.

How is should we identify the link quality with a specific AP when multiple AP's are connected (or at least emitting data)?

How do we know we are showing the right information with the right AP?

Or are we looking at this issue in a completely wrong way?

Thanks in advance.

Hylke

[Hamish Willee]

Hi Hylke,
Perhaps SYS_STATUS - see https://github.com/mavlink/c_library_v2/blob/master/common/mavlink_msg_sys_status.h#L14
As you're working on PX4, if this does not help suggest you repost on the PX4 discussion boards: https://discuss.px4.io/c/mavlink/23 to get some stack-specific expertise.

Regards

Hamish

[Hylke Faas]

Hi Hamish,

Thanks for the reply. Unfortunately the SYS_STATUS message seems too generic for this purpose (also showing CAN and I2C dropouts).

I was expecting it was not PX4 specific issue, but I'll check in on the PX4 board.

Kind regards,

Hylke