# voxl-mavlink-server external FC Bus Error

Source: https://forum.modalai.com/topic/2125/voxl-mavlink-server-external-fc-bus-error
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2023-05-03 18:29:41 UTC by Steve Turner
Replies: 4 · Views: 1384

## Steve Turner · 2023-05-03 18:29:41 UTC

We were running a VOXL-1 based system off of staging.

Aftern an `opkg update` and `opkg upgrade` it looks like the MAVLINK server is broken. We're investigating now, just wanted to get this out there.

```
voxl:~$ voxl-mavlink-server
loading our own config file
=================================================================
Parameters as loaded from config file:
primary_static_gcs_ip:        192.168.8.10
secondary_static_gcs_ip:      NULL
autopilot_uart_backup_bus:    12
autopilot_uart_bus:           5
autopilot_uart_baudrate:      921600
udp_mtu:                      0
en_external_ap_timesync:      1
=================================================================
Successfully opened primary mavparser on bus 5
Starting primary thread for bus 5
Successfully opened backup mavparser on bus 12
Starting backup thread for bus 12
got first packet on bus 5, stopping the other bus: 12
Adding primary GCS IP address from conf file to list: 192.168.8.10
Added new UDP connection to 192.168.8.10
Not connecting to secondary gcs ip: NULL
Added new UDP connection to 10.147.20.136
CONNECTED to GCS at 10.147.20.136
Init complete, entering main loop
Detected Autopilot Mavlink SYSID 1
thread for bus 12 trying to close
thread for bus 12 Successfully closed
Bus error
```

If I rollback the mavlink server to previous versions it seems happy but I can't connect to `voxl-vision-hub` through the mavlink server from something like QGC.

## Reply by Zachary Lowell 0 · 2023-05-03 19:05:55 UTC

Hi Steve,

If you are using the dev branch of mavlink-server then you do not need voxl-vision-hub to communicate with QGC. If you are using the previous version from sdk0.9.5 then you need voxl-vision-hub to communicate with qgc.

What exactly are you trying to do here? Are you configuring voxl-mavlink-server and voxl-vision-hub using the voxl-configure tool? Are you using both the dev branch for voxl-vision-hub and voxl-mavlink-server?

Zach

## Reply by Steve Turner · 2023-05-03 19:16:11 UTC

Zach,

Thanks for the quick response!
I can run both on the dev branch, or roll back to staging.

I thought that voxl-vision-hub would talk to the voxl-mavlink-server which handles all communication with PX4.

From there voxl-mavlink-server forwards between visionhub, px4, and QGC once it connections.

I'll try running the new config tool again to see if that cleans anything up.

Anything else to look for for the bus error?

## Reply by Zachary Lowell 0 · 2023-05-03 22:52:15 UTC

@Steve-Turner said in [voxl\-mavlink\-server external FC Bus Error](/post/9932):
> Anything else to look for for the bus error?
> 
> 

Yeah no problem! 

So as of the dev branch (which is the latest and greatest dev code) pretty much all mavlink esc forwarding is now handled by voxl-mavlink-server. Which is why you shouldn't need it for qgc connection anymore. Which method of internet are you using? Softap, station? Are you connecting to the voxl wifi or communicating over a LAN?

As for the bus error, could you give me a bit more as to what you are doing hardware wise?

## Reply by afdrus · 2023-05-31 13:02:40 UTC

I am also trying to understand this. I was able to forward the mavlink messages from voxl to the station via wifi (using voxl-wifi station), but I am not able to specify the port as it streams everything to the default port 14550. How can I specify the port to which I can send the telemetry?