GNSS NMEA Input impossible

I like input NMEA sentence on GPS1 port.

My GNSS send RTK position, it’s a rover who received correction by 4G modem by connection to NTRIP Caster or by radio modem when corrections are transmet by my GNSS Base.

GPS_SBP_LOGMASK: -256 (I don’t understand this option and I don’t test -1 or 0)

My GNSS output data by DB9 RS232 femelle , I build a cable with DB9 male to GPS1 connector, Pin2 DB9 to Pin2 GPS1, Pin3 DB9 to Pin3 GPS1 and Pin5 DB9 to Pin8 GPS1. I test another cable, Pin2 DB9 to Pin3 GPS1, Pin3 DB9 to Pin2 GPS1 and Pin5 DB9 to Pin8 GPS1.

Has anyone made this kind of connection before? I can find no information about it!
Is there a documentation that details the frames and parameters for using the NMEA data of a GNSS RTK for navigation(Boats) and the log of the positions of a measurement (sonar in my case).


rs232 is wrong voltage level
Cube requires ttl serial, not rs232 serial, you need a converter

Thanks a lot for the information, I basically thought that just put RX on TX and TX on RX. I’ll order a converter and go back on the operation.
A simple SERIAL to USB converter don’t do that?
Sorry for my English, I’m French.

I come back for explain my solution.
I have order a low cost converter by Amazon, but it’s not work after some test.
Finaly I buy a Sparfun converter PRT-08780, and it’s OK I can use my Survey GNSS!

I am using rtk since some weeks. Tersus GNSS . I can see RTK FIX on MP screen . Do you Change any parameters of pixhawk for high accuracy flight ?

For the moment I can’t doing test in France, my project is a boat.
On my boat I have a rover GNSS who receive correction by his radio from a base install on know point.

Rover send NMEA GGA, RMC and VTG at 5Hz,115200 baud to Pixhawk. I don’t know if RMC and VTG are use by Pixhawk, no docs for explain what NMEA message are importante for navigation.

Without navigation test I have juste change EK2_ALT_SOURCE at 2 for use altitude from GNSS and no barometer, it’s important for my project to have ellipsoid height for referencing my bathymetrie on french system.

After first test, if I change parameter I come back here.