Bad GPS health and bad gyro health

matek405wing. with latest firmware at 18/june,2021. I can arm my plane with 15 sat above, but. It keep telling me bad GPS and bad gyro health.

Probably because you have too many GNSS constellations active, and that reduces the update rate of the GPS receiver bellow 5Hz

I tried GPS GNNS SBAS. each one, or each two of.them. or change 100ms to 200ms. or change gps modules. it still tells bad bad bad…

You can not tell a GPS receiver to give you data at a faster rate than it can calculate.

If that would be possible we would all buy cheap GPSs and configure then to run at 100Hz.
You understand that, right?

How exactly did you limit the satellite constellations? What parameter did you change?

yes i understood the limits of every gps.

At first I used the default setting, Which auto configure GPS. It tells bad gps health. So I did some search here and someone said, Try to turn off gnns. or change the hz/sec with ms. I can get the full data of gps copy tomorrow.

By the way, I always set the GPS with u center Before I connect the GPS module with the flight control. the baud was 57600, Why it always change to 208…something later Automatically.

It should change to 115200 automatically.

How exactly did you limit the satellite constellations? What parameter did you change?

I used the default but it did not work. so I changed something. why I can still fly even it keep telling me gps not health.

what are the parameter setting about this?

Satellite constellation. I cannot find this setting up on mission planner. Or maybe do you mean in the U center?

With 4.1.0beta it was fixed, that the FC can activate the Galileo constellation.
Parameter GPS_GNSS_MODE
With NEO M8N activate at most 3 constellations depending on your location.
With SAM M8Q it seems to be OK to activate 4 constellations.
This doesn’t explain bad gyro health

If you are not using a compass then you need to adjust the arming param

https://ardupilot.org/copter/docs/common-compassless.html

@RainFly
my location is china east.I tried gps,sbas,glonaa,galileo. with each one only or each two only. it still tells Bad Gps Health. photo attached is my gps.

yes I already deactivated the 3 compass.

Have a look at the linked info, the AHrs needs forward movement to align and will come good after launch

@Will_Fisher
does good after launch explain that I can still fly even it tells bad gps health.

can I do this?

EKF3 to always use GSF set EK3_SRC1_YAW = 8 (GSF)

The uBlox driver in the code will change the configuration of the attached GPS receiver to what it wants. I found this out also :frowning:. It goes for the higher baud rate, which is fine most of the time, unless you want a slower baud rate for other reasons.

Did you configure GPS_GNSS_MODE bitmask parameter?

@amilcarlucas
yes i did. Every each one or every each 2 I have tried. But still tell bad GPS health. can you tell me what could go wrong?