Hello,
I’ve been experimenting with a small GPS antenna/receiver from Origin GPS called the Nano Hornet with my pixracer autopilot. Using u-blox u-center, I can get a 3D fix with an HDOP of 0.9 and about 13 satellites in under a minute. Also, using tera term and an ftdi cable, I can see NMEA messages, that indicate a 3D fix with an HDOP of 0.9. However, I’ve never seen better than a 2D fix on Mission Planner, and the HDOP is always reported as “100.0” with about 10 satellites. These are my parameter values:
GPS_AUTO_CONFIG 1
GPS_AUTO_SWITCH 1
GPS_GNSS_MODE 3
GPS_GNSS_MODE2 3
GPS_INJECT_TO 127
GPS_MIN_DGPS 100
GPS_MIN_ELEV -100
GPS_NAVFILTER 8
GPS_RAW_DATA 0
GPS_SAVE_CFG 0
GPS_SBAS_MODE 1
GPS_SBP_LOGMASK -256
GPS_TYPE 6
GPS_TYPE2 6
Despite seeing NMEA messages out of the GPS, setting the GPS_TYPE to 5 (NMEA) doesn’t seem to work, and 1 (Auto) is the only value other than 6 (SiRF) that has worked for me. The nano hornet includes a SiRFstarIV SoC, but I’m not familiar with how MP handles that data differently.
Is it possible that some information is being missed in the GPS sentence parsing? I’m not much of a programmer, so I’m not really sure where the appropriate place to investigate in the code would be. If anyone has suggestions, they would be greatly appreciated!
Edit: I’m using MP 1.3.41 and Arduplane V3.7.1
Thanks