I get the error message “Prearm: ahrs: ek3 sources require GPS” and cannot arm my drone despite it arming fine before the upgrade to 4.4.2. My compass works and I get GPS lock and GPS home set. I attach my params. Should I provide a log file while disarmed too? I’d be really grateful for some help to work out why it’s not arming. Thanks.
ek3.params.txt (29.1 KB)
I made another attempt to fly today but with logging while disarmed enabled. Here is the log:
HDOP was 1.3 towards the end of the drone being powered on which is well below the 2 required for arming.
My arming bitmask is:
You need to fix that barometer warning message before anything else…
I have news! The problem is due to Arducopter and nothing to do with my hardware.
I tested various firmware versions and found that I had no baro problems with 4.3.8. As soon as I upgraded to 4.4.0 I see this error message:
“Bad Baro Health”.
You’ve already seen the error I get with 4.4.2 which is similar. BTW, the title of this thread is wrong - there is no GPS problem in any firmware.
I read the 4.4.0 release notes and lo and behold, Arducopter is no longer compatible with my board because I have a DPS310 barometer and now the firmware only supports BMP280 “to reduce code size”. This is pretty crap. 
I suppose I’ll have to try and compile my own firmware with this feature enabled.
Glorious! Thank you, I was just about to faff around with my own git clone/waf and start hunting down the #define for DPS310.
Here is the complete build for anyone else wanting DPS310 enabled:
Be warned that I disabled rangefinder, VTX and some other stuff but it’s easy to create a new build that includes these.
This should be ok in 4.5 - we rationalized what got enabled and disabled. If you can verify that would be great
I would like to help with this. Where is the 4.5.0 build?
It doesn’t arm. I haven’t checked the full log yet but I’m 99% sure the abreviated message on my Taranis was the same as with 4.4.2. i.e. barometer not working
