We got our 406 yesterday, and took it out for testing today. Hooked it up to our 5V source, and got a lock within a minute. We continued testing using the GPS, turning it on and off and getting a lock in under a second, it took longer for our processor to boot than to get a GPS lock. SO we finished our testing and brought the board inside for awhile to do some other tasks. When I went back outside to test further, the LED comes on, but we cannot get a lock. We checked the connections (power and grounds) and the data coming from the transmit pin indicates we have at least 9 satellites in view. Anyone know why we can no longer get a lock?
9 satellites in view = you have a lock
one of your commands may have simply disabled the LED, it’s related to one of the NMEA messages, i forgot which, but 3 or more satellites in view means you have a position fix
frank26080115:
9 satellites in view = you have a lock… 3 or more satellites in view means you have a position fix
Not quite. The presence of signal from N satellites is merely that, a measure of availability. Once you have at least 3, position fix calculations can begin, but it’s not instantaneous. Signal noise, drop-outs, and reflections can create multiple conflicting “fixes”, some of which may skip around at “impossible” speed. Depending on how bad things are, it may that the computer more than a minute to sort the good from the bad and give you a position.