hello there
i am using two gps one is NMEA gps at gps1 port and another here3 GPS at can1 port of pixhawk cube orange and setted up the below parameters
can_p2_drivers 1
can_d2_drivers 1
gps_type2 9
gps_type 5
serial3_protocol 5
serial3 baud 115
when switching in poshold mode i got a pre arm error of gps blending unhealthy
please help with this
thanks in advance
don’t use GPS blending, use the GPS with the best lock, blending a good position fix with a worse position fix just gives you a worse position fix.
Should the satellite number be a problem as my NMEA gps gives me 30-35 sat while here3 gives me 15-16 sat
no it goes by the HDOP, the reason for the different satelite count is that the nmea gps is using more constellations, The here+ is probably only using GPS and GLONASS where the NMEA GPS is probably picking up BeiDou and Galileo too but not actually using them.
The receiver will use the most accurate constellation that it can pick up, so usually GPS
But when I use single * here3* it give hdop below 1 or precisely 0.6-0.8 while NMEA gives me 0.3-0.4 hdop when at 32 satellites. Also I agree that NMEA uses beiudo and glonass also
Then use the NMEA as primary, the here3 is almost 10 years old. it wasn’t that good a receiver.
hdop/accuracy interpretation from a manufacturer is different from the hdop/accuracy interpretation from another manufacturer. Hence blending is not suitable for two GNSS from different manufacturers.
Use failover and select the best GNSS as primary. Reduce the number of allowed constellations on both GNSS receivers to two.
here below i am attaching link its logs and video of flight below at drive link
https://drive.google.com/drive/folders/1Z6AptoEEbj_OJePuKqv4G9M0vfJNbcA7?usp=sharing
please help me out of this
Things usually get unhealthy when there are too many Stellites. It causes the update rate to fall bellow 200ms (5Hz)
So:
How can I know which two.constellation I should configure
@amilcarlucas also how it will be helpfull as I my gps is refreshing at 5hz only I also attached log and video for poshold flight I have taken in above link
That is helpful because less processor load means higher refresh rate. Simple common sense.
And EKF timesout at 200ms, that is a simple hard fact.
The constellations depend on where you live. Google should help you there: “Which GNSS constellations provide better service in India?”
I will try and update you