SparkFun F9 Pixhawk Cube Integration

Happy New Year!

I am thrilled to see support for the U Blox F9 in Plane release 4.02. Thanks to Trige and all other developers for the continued development and their support.

With 4.02 I am trying to integrate a SparkFun GPS-RTK2 Board - ZED-F9P (Qwiic) with a Pixhawk Cube. I modified the GPS 1 wiring harness that came with the Cube by cutting off the GPS connector and soldered VCC, TX, RX and GND to UART 1 on the Spark Fun board. For now, I don’t plan on adding an external compass. The Spark Fun board is getting power from the pixhawk and is working fine. I can easily view its status via u center.

In Mission Planner, I checked or set the following parameters:
Serial3_BAUD: 38
Serial3_Options: 0
Serial3_PROTOCOL: 5


All other GPS settings are default parameters

In U Center

UART1 BAUD rate defaults to 38.4

I have tried several message out types
None seem to work.

So I have a few questions:

Will Plane 4.02 automatically configure the F9 through UART?
Should F9 UARTINPROT be none or UBX?
What messages should I send from UART1?

Any help or insight is greatly appreciated,

Wishing you the best in the new year,


Hello Dave

I am facing similar issues with the GPS-RTK2. Did you manage to solve the problem? If yes what did you do to solve it? Looking forward to hearing from you.


It’s been awhile and I covered a lot of ground since I posted. The good news is I got it working, the bad news is I may be confusing the fix with something else. If memory serves, the pixhawk was overwriting the F9 config file causing some baud rate conflicts. Make sure the SparkFun UART is talking at an acceptable baud rate 38.4, 57,6. Configure the serial port on the pixhawk gps port for the same baud rate and ensure GPS_AUTO_CONFIG is set to 0.

hope this helps.

Thanks Dave for sharing the information.

Another question Dave. Before hooking to the two GPS-RTK2 did you configure the base and rover mode first?

It needs to be configured the way you want it prior to being connected. Sounds like you are using a base and rover. I am using the GPS-RTK2 as a rover, connected to a pixhawk.