What specific software and hardware combo limits you to 12 sats?
My guess for the different counts is differing signal quality thresholds. Some systems require a higher quality signal in order to count the satellite. Apparently some systems count any satellite in the sky.
I consistently see more satellites listed in the u-center software than the number of sats indicated on the OLED of the GPS module.
If you use 3 constellations, for example gps, glonass, galileo, arducopter does not work well. There is a patch for this problem but it is not yet integrated into 4.0.7 FW
I’m pretty sure those two systems are all that is available for those devices. The devices you mentioned are listed as “GPS and GLONASS.”
I think you need “dual-band” modules to pickup Galileo or BeiDou satellites.
I don’t know if in plane the galileo fix is ​​integrated, but in copter it is integrated by the 4.1 beta. With the BN220 and the copter with 4.0.5 custom FW (with galileo fix) I got +20 sats.
Yes, the fix linked is also in the Plane and Rover releases. Unlike previous releases, this time we’ve sycronised Plane, Copter and Rover so they are all nearly identical.