SIYI F9P RTK Module connected to Cube Orange+ GPS1 gives "No GPS" (Works fine in u-center)

Hardware Rovers and boats
1

Hi everyone,

I am trying to connect a SIYI F9P RTK GNSS module to a Cube Orange+ flight controller running ArduRover, but Mission Planner continuously reports “No GPS”.

Here is what I have verified and configured so far:

1. Module Verification (PC / u-center):

  • Connected the SIYI F9P module to a PC via its Type-C USB port.

  • Verified using u-blox u-center: The F9P chip powers up normally, acquires satellite lock, and outputs telemetry messages (UBX/NMEA). The module hardware is confirmed fully functional.

2. Physical Connection:

  • Connected the module’s UART1 port to the Cube Orange+ GPS1 port using the standard 8-pin JST-GH cable that came with the Cube.

3. ArduPilot Parameters:

  • SERIAL3_PROTOCOL = 5 (GPS)

  • SERIAL3_BAUD = 115 (matched with u-center configuration)

  • GPS_TYPE = 2 (Auto)

  • AHRS_EKF_TYPE = 3

  • AHRS_GPS_USE = 1

Despite the module being operational, ArduPilot fails to establish UART communication over SERIAL3.

  1. Has anyone integrated this specific SIYI F9P RTK module with a Cube Orange+?

  2. Is there a known TX/RX pinout crossover mismatch between the SIYI UART1 port and the standard Cube GPS1 JST-GH cable?

  3. Are there specific u-center UART1 port settings (e.g., specific NMEA/UBX message rates) required for ArduPilot auto-detection?

Any guidance, pinout diagrams, or suggestions would be greatly appreciated!

Thanks in advance!

2

For debugging, try setting the GPS_TYPE = ublox instead, and try the serial option to swap tx/rx if you think that is messing things up. After that, GPS_AUTOCONFIG = 1 should get you the rest of the way.