When connecting APM with a serial terminal, the APM will start up with GPSERR messages over the serial connection.

During supply of regular flight data (telemetry) these messages will appear every once in a while. This might be the source of some erratic behaviour in hold mode.

Serious investigation needed as far as I am concerned; the GPS libraries should NOT directly access the serial port for anything. We should capture errors produced by libraries and handle them appropriately.

Can someone please look into this asap ? I'm concerned about it. My setup is MTEK v.1.6, without a fix, Stable mode but no ALT or GPS hold. Connect with serial monitor and instantly get 5 or 6 lines saying "GPSERR: Bad sentence!!"

Looks like the issue is resolved with new libraries. Can you confirm?

Emile