Cannot connect secondary GPS with NMEA data only (Tersus)

Hi All,

I got a RTK module from Tersus. Their manual says that a NMEA output from a rover unit should be detected automatically by Pixhawk. However, I got no luck with a Pixhawk (HKPilot32) that is working perfectly with dual ublox M8N modules. I have checked the serial output and baud rate of the NMEA with various software (u-center, NMEA306) and quite certain that the output from Tersus is correct.

For the pixhawk, I have already tried the followings

  • Test GPS_TYPE, GPS_TYPE2 setting with 1:AUTO and 5:NMEA
  • Test GPS_GNSS_MODE with various value (0, 1, and etc)
  • Change baud rate of serial port (3/4)
  • Set Tersus NMEA output baud rate and message frequency (38400, 57600, 115200 with 5 Hz for gga, vtg, rmc)
  • Checking logic level with oscilloscope also show a correct voltage (3.3)

Still got no luck :cry:

Any help or suggestion for debugging would be very appreciated

1 Like

Please check my solution here https://github.com/ArduPilot/ardupilot/pull/4085

Thanks @mahisorn, I have a longstanding request open for this :slight_smile: