I ended up buying a new
GPS module. The other M8N module that I had ordered from eBay
was either dead on arrival or I damaged it by powering it with 5V
for a while before I realized that it preferred 3.3V.
Also with the new module I was able to upload the AssistNow offline
data via the u-center software. Trying to do this with the other
module gave me lots of errors before. Maybe it had an issue with its
I can highly recommend this new Drotek module. The copter seems like
"nailed to the sky".