# GPS streaming

Source: https://forum.modalai.com/topic/3667/gps-streaming
Category: General Questions (https://forum.modalai.com/category/2/general-questions)
Posted: 2024-07-23 20:04:50 UTC by groupo
Replies: 7 · Views: 1215

## groupo · 2024-07-23 20:04:50 UTC

I'd like to pull GPS positions off of my drone as it is flying. I am not sure the best way to approach this. I know GPS info is part of the MAVLink stream being sent to QGC. Is it possible to have voxl-mavlink-server stream a specific message to a different IP in parallel? Or, is it simple enough to pull the GPS data off of QGC in realtime? I tried consulting the docs for mavlink-server, but that entry is particularly sparse. TIA

## Reply by Eric Katzfey (ModalAI staff) · 2024-07-23 21:00:55 UTC

@groupo You can modify voxl-mavlink-server to send to a parallel IP. Or you can write a separate application that listens to the mavlink pipe published by voxl-mavlink-server and have it forward GPS info to another IP. The voxl-vision-hub application reads mavlink messages this way and can be used as an example. Check the file: https://gitlab.com/voxl-public/voxl-sdk/services/voxl-vision-hub/-/blob/master/src/mavlink_io.c?ref_type=heads#L120

## Reply by groupo · 2024-07-25 20:12:39 UTC (in reply to Eric Katzfey)

@Eric-Katzfey by parallel IP do you mean changing secondary_static_gcs_ip to whichever IP I desire?

## Reply by Eric Katzfey (ModalAI staff) · 2024-07-26 15:39:41 UTC (in reply to groupo)

@groupo Oh, yeah, that should work. Did you try it?

## Reply by groupo · 2024-08-12 14:57:49 UTC (in reply to Eric Katzfey)

@Eric-Katzfey not yet, had to shift gears but will be coming back to the drones soon though. 

For clarity, you are saying that the Sentinel will stream to both primary and secondary GCS, both on port 14550, even if a GCS connection is established on the primary?

## Reply by Eric Katzfey (ModalAI staff) · 2024-08-12 15:31:11 UTC (in reply to groupo)

@groupo Yes, that's the intention.

## Reply by groupo · 2024-09-24 13:04:15 UTC (in reply to Eric Katzfey)

@Eric-Katzfey I put up another post yesterday inquiring about this from a different angle. I stayed away from this because, while I can write C code, I am a little lost on how to compile and run it. I am particularly bad at setting up dev environments and try to leave that to the software engineers, haha. Even if I wrote what you were suggesting, it is still a mavlink message I would have to parse yeah? I have had trouble parsing the ulog files with pyulog. I can that messages exist, but I am not sure how to view them. At the end of the day, I really just want ideally a way to stream/send GPS truth data to a matlab process I am running on a host PC

## Reply by Eric Katzfey (ModalAI staff) · 2024-09-24 16:47:45 UTC (in reply to groupo)

@groupo I responded to your new post.