# Starling 2 Max with Ublox F9P Ultralight

Source: https://forum.modalai.com/topic/4403/starling-2-max-with-ublox-f9p-ultralight
Category: Development Drones (https://forum.modalai.com/category/44/development-drones)
Tags: starling
Posted: 2025-05-07 21:22:29 UTC by Sam Kiley
Replies: 6 · Views: 1721

## Sam Kiley · 2025-05-07 21:22:29 UTC

I am using the Holybro F9P Ultralight with the starling 2 max but am not able to get gps data from the F9P. This is in relation to this post, trying to get around the self-jamming gps issue on the voxl2 with modem stack: 
https://forum.modalai.com/topic/4226/starling-2-max-no-gps-data/44

I have voxl-px4.conf GPS set to auto, so then it runs px4-qshell gps start. 
When I look at the px4 logs, I see this being repeated:

May 02 20:57:54 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: u-blox firmware version: HPG 1.51
May 02 20:57:54 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: u-blox protocol version: 27.50
May 02 20:57:54 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: u-blox module: ZED-F9P
May 02 20:57:54 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: GPS UART baudrate set to 115200
May 02 20:57:54 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: Got ack to initial CFG_VALSET!

There is never outputted this line: (Which form other forum posts seems to indicate a real successful connection):
INFO  [uORB] Advertising remote topic sensor_gps

Also, my px4-listener sensor_gps says:
voxl2:/$ px4-listener sensor_gps
never published

and then px4-qshell gps status outputs in the logs:
May 02 20:57:33 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: qshell gotten: gps status
May 02 20:57:33 m0054 voxl-px4[1746]: INFO  [muorb] SLPI:   arg0 = 'gps'
May 02 20:57:33 m0054 voxl-px4[1746]: INFO  [muorb] SLPI:   arg1 = 'status'
May 02 20:57:33 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: Main GPS
May 02 20:57:33 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: protocol: UBX
May 02 20:57:33 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: status: NOT OK, port: 6, baudrate: 115200
May 02 20:57:33 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: sat info: enabled
May 02 20:57:33 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: rate reading:                      0 B/s
May 02 20:57:33 m0054 voxl-px4[1746]: INFO  [muorb] SLPI: Ok executing command: gps status

I also went into the u-center with the F9P and made sure that ubx was a protocol for in/out.

voxl-ardupilot doesn't have any issues connecting, so wondering if this is just a px4 gps driver issue specific to the voxl setup. I am on voxl-suite 1.4.1
Any advice on this? Thanks for any info

## Reply by Eric Katzfey (ModalAI staff) · 2025-05-07 22:09:37 UTC

@Sam-Kiley Not sure, we haven't tried that one yet. Since it works with voxl-ardupilot that pretty much confirms that it is wired up properly. You could try with a mainline build such as: http://voxl-packages.modalai.com/dists/qrb5165/dev/binary-arm64/voxl-mainline-px4_1.16.0-1.0.2-202505070835_arm64.deb

## Reply by Sam Kiley · 2025-05-07 22:44:01 UTC

Eric, Thanks, yeah I suspected that it was some sort of version thing with px4 where they support it now. 
Could you explain what the difference between mainline px4 and what I probably have loaded? or is it just because the VOXL SDK 1.4.1 is slightly behind?

Thanks

## Reply by Eric Katzfey (ModalAI staff) · 2025-05-07 23:05:51 UTC (in reply to Sam Kiley)

@Sam-Kiley our fork is based on pre-1.14.0 PX4. But mainline PX4 now runs on VOXL 2 at (almost) feature parity so the voxl-mainline-px4 package bundles up a mainline version (in this case v1.16.0-rc1).

## Reply by Sam Kiley · 2025-05-07 23:36:27 UTC

I did wget from the voxl2 over wifi to get the package in / directory. dpkg -i on that results in this error:

voxl2:/$ dpkg -i voxl-mainline-px4_1.16.0-1.0.2-202505070835_arm64.deb
Selecting previously unselected package voxl-mainline-px4.
(Reading database ... 105523 files and directories currently installed.)
Preparing to unpack voxl-mainline-px4_1.16.0-1.0.2-202505070835_arm64.deb ...
Unpacking voxl-mainline-px4 (1.16.0-1.0.2-202505070835) ...
dpkg: error processing archive voxl-mainline-px4_1.16.0-1.0.2-202505070835_arm64.deb (--install):
 trying to overwrite '/data/px4/etc/extras/actuators.json.xz', which is also in package voxl-px4 1.14.0-2.0.94
dpkg-deb (subprocess): decompressing archive member: lzma write error: Broken pipe
dpkg-deb (subprocess): cannot copy archive member from 'voxl-mainline-px4_1.16.0-1.0.2-202505070835_arm64.deb' to decompressor pipe: failed to write (Broken pipe)
dpkg-deb: error: <decompress> subprocess returned error exit status 2
Errors were encountered while processing:
 voxl-mainline-px4_1.16.0-1.0.2-202505070835_arm64.deb

I currently have voxl-ardupilot and voxl-px4 stopped and disabled.

Any ideas on this?

## Reply by Eric Katzfey (ModalAI staff) · 2025-05-08 00:31:01 UTC (in reply to Sam Kiley)

@Sam-Kiley Yeah, try `dpkg --force-all -i <package-name>`

## Reply by shawn_ricardo · 2025-05-22 22:36:35 UTC

Just wanted to share: Using this approach, I was able to integrate CubePilot Here4