I tried in vain to get the iOS Ground Station app to reconnect to my BT Datalink. This worked last summer, and worked for about two minutes today, then it lost bluetooth signal, and I could not get Ground Station to reconnect. I gave up and installed the PC Ground Station and that seems to work. So it doesn't appear to be a hardware problem with the Datalink itself.....

Did you check The btu reset located in the assistant software , same area where you do the IMU calibration. I am just the opposite.  My PC Groundstation won't stay connected but the IPad version does ok. I happen to like the PC version better but. Can't get it  to work properly.EDIT. I just saw your post on another thread where you had already tried this and it did not work. Are you using IOS 8.3? There have been some reported issues with that and the GS. Remove and reinstall the app? Not sure what else you could try.

What is the led status of the BTU?

nsvr66@gmail.co Posted at 2015-6-18 08:12
RED... ALWAYS RED.... STEADY RED

You've got an issue with the btu....as soon as you power on the Phantom the LED on the btu should turn green. ( or blue..can't remember....any way anything but RED)