I have two VR cards:
One VR Brain 4.5 with uBlox 6 (3DR GPS) flying an Hexa and one µBrain with uBlox 8 on a smaller Quad.
I upgraded both to latest rc10 version. VR Brain 4.5 is OK (also with EKF) but µBrain GPS performance is poor. Compass calibration is fine. Included is the latest flight log with GPS errors. I had a look at the GPS prediction yesterday and checked the GPS reception with µBrain: it is like there is no GLONASS acquisition.
Thanks a lot for having posted your two flights results on two different quadrirotors ,
one with M8N form VR,
the other with M8N from RTFquad 35x35mm
Your two flights were successfull
Both of them show INAVERR in logs
As of today we can say all M8N shows INAVERR errors (sometime with max value of 255)
But INAVERR errors have also been seen with 3DR GPS LEA 6H ( with lower values...)