Ok let me address these one at a time. First the GPS unit. If you read through the directions very carefully, it addresses mounting. Try to keep it text up and as out of the way as possible, I like just under or even inside the canopy. Next, if you have followed the mounting instructions and have the GPS enabled within your transmitter, it takes a good 5 to 8 seconds for the unit to "Lock" to the satellites. Also, I need to go outside the house.
Now for the RPM on the iPad, this is very dependent on the type of RPM sensor that you are using. My personal favorite is the optical pick-up where you put a small silver tape on the back of a prop spinner. Second best is the Hall effect sensor for nitro engines. Last resort is the electronic pick-up off the ESC for electrics. These electronic pick ups usually take longer to average out the pulses. If you are running electric try going the Optical route.
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