GPS configuration RC7


Hi I am testing with RC7 and get weird messages about the gps configuration:
Sometimes the baud rate is 115200 mostly 38400 from messages?
Is there a way to get allways the same configuration?
Should I preconfigure something in the GPS (baud, Hz, etc.) in 3.4?
What about the x,y,z offsets. Is there a picture to setup them correctly?
I am using the M8N Ublox device.


Can you provide a log or say what exact message you are getting? It looks like you have auto configuration enabled but ArduPilot isn’t able to configure your GPS.

The Message was “GPS0 using 38400baud” or 115200baud in the messages tab of MP.
In the meantime I configured the GPS itself and the serial port to 115200.
It seems to be stable now.
Maybe there are some defaults which should be changed?
The problem with wrong configured GPS seems to be very critical with EKF.
For me its an old story with GPS and EKF (flying under trees 2 crashes in 3.3)
Hopefully in 3.4 its saver when GPS is getting poor reception?
Maybe you can give me a link to the code or the wiki where the recommended settings for the different gps modules are?
Is there anything I should knew about the mounting offsets?
I will add the logs and my configuration later.
Thanks for reply.3.4RC7_10Hz_GPS.param (10.2 KB)
2016-10-26 15-17-00.tlog (169.0 KB)

If you’re always using a Ublox it may also help to set the GPS_TYPE to 2 (“Ublox”). In general I don’t think this is necessary but anecdotally, I have one vehicle that would some times have trouble figuring out which GPS it was using and setting this fixed it. That was an old AC3.4 release candidate though.

Including a dataflash log would be very helpful.

We don’t support setting of x,y,z position of the GPS (or other sensors) in AC3.4. That should come with AC3.5.

Thanks for using the new version and providing feedback!

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This relates to some changes where we raised the desired baud rate of the u-blox to 115200 for all GPS’s. However it’s technically possible to detect the GPS before the GPS has been reconfigured to the higher baud rate which you appear to have hit. I will get this fixed up, it should be an easy change and prevent this scenario.

There should be no difference between setting GPS_TYPE to 1/2 for detecting the GPS unless you happen to have NMEA enabled by default, which is very very rare for that to cause a problem.