I’m working on integrating the simpleRTK3B with compass into the BlueBoat platform. The reason for this is that I believe compass calibration is nearly impossible after adding extra hardware (sensor platform, etc.). If this assumption is incorrect, please feel free to correct me!
However, I’m running into serious stability issues:
Sometimes GPS signal is received and shows good values:
→ 24–28 satellites, HDOP ~0.5, 3D fix
But the signal drops intermittently with no clear pattern, making the GPS very unstable
I’ve tested different GPS output rates, still experiencing frequent dropouts
If anyone has experience integrating ArduSimple GPS with BlueBoat, or has any advice on how to resolve this instability, I would greatly appreciate your input.
Hi @andycyl -
The large vehicle compass calibration, followed by processing a log file of driving around manually with (default) GPS position lock active should be enough to get a very good compass calibration using the default compasses, without relying on RTK. Download a .BIN log that corresponds to that activity, process it with this tool, and use the resulting params file to update your calibration values via the Autopilot Parameters menu > Load.
That said, what you’re seeing definitely is unusual. We tested that RTK while evaluating options and didn’t have the best experiences with it. Do you see more than one GPS detected in BlueOS, in the upper right corner? If not, something is likely not configured correctly…
If you can log and share the output(s) of your RTK GPS units, that may be helpful in diagnosing what is going on!
Hi @andycyl -
If the stock GPS was connected at the same time as your RTK, that is likely the root of your problems.
As for heading, your log shows no HDT messages from the GPS, so no heading would be expected!
Generally we were frustrated with RTK2B, not the RTK3B you’re using (haven’t tried that.) In my experience, both GPS connections need to be made to two USB ports on the vehicle (or Navigator Serial ports at appropriate 3.3v TTL) and each configured in the Autopilot Firmware, Serial Ports page (in pirate mode.) BlueOS should reflect that both GPS are connectd in the upper right (as opposed to just showing info from one.) Make sure you’re running the latest stable, 1.4.2!
Is it not recommended to use the stock GPS and RTK gps simultaneously?
My system uses the stock GPS primarily for navigation, and RTK gps is being logged. We did just integrate the RTK into the autopilot, but it kept dropping out (GPS status goes from 20 sats to 0 constantly).
I’m using an Inertialsense RUG 3 DUAL IMU/RTK and the NMEA messages are being converted to mavlink on the navigator RPI.
Hi @CA_BlueBoat -
Correct - the Autopilot can only parse RTK GPS or standard GPS, using 3 GPS at the same time is not possible! If you’re just logging the RTK GPS, and not sending it to the autopilot at all, that should be ok. However, if you’re streaming RTK NMEA from both the RTK GPS, you’ll want to disable the stock GPS…
How to set up simpleRTK3B Compass with Unicore UM982 in ArduPilot