"For those having problems getting the Locosys LS20031 GPS programmed, here’s how I did it:

(1) Purchased a 3.3V USB TTL-232R cable (available from many sources).
(2) Powered the GPS via the 3.3V output on an arduino board.
(3) Plugged the TX/RX…"

"Would this be more efficient?

//calculate rhumbline distance in nautical miles
if (cos(true_course) == 0.0)
distance = 60.0 * (point2.longitude - point1.longitude) * cos(point1.latitude);
else
distance = 60.0 * ((point2.latitude - point1.latitude)…"