Hello everyone.
I'm using Quectel L86,Tinygps++ library with hardware serial pins to get the signals from the chip,But it's taking much time like 20-30 mins to get Latitude and Longitudes, moreover it's locking to 3 and 4 satellites.
Why it's taking that much of time,perhaps Android phones will take a seconds to lock Gps satellites.
Please help.
thank you.
Not sure what you are running into with your receiver, but phones "cheat" - from something I came across the other day, they apparently get information from the cell tower as to the approximate location as well as what satellites are currently visible - that makes it a LOT easier for determining position because on a cold start of a gps, it has to listen for all possible satellites then start determining where it is as it finds them (and gets some additional information from them). Having a basic knowledge of current position as well as which satellites to listen for is a big advantage for the phones (I too had wondered how the phones came up with a position so fast so it was interesting to come across the information about what was coming from the cell towers). Be interesting to see if/ or how long it takes a cell phone to determine position if you are in a location with no service so it has to do all the work itself.
Are you outdoors, with a clear view of the sky?
All GPS units take a long time (up to 15 minutes) when they perform a true "cold start", that is with no prior knowledge of the satellite locations. Those with an on-board battery backed memory of recent satellite locations can be quite fast to start up, but if the battery dies they start all over every time.
jremington:
Are you outdoors, with a clear view of the sky?All GPS units take a long time (up to 15 minutes) when they perform a true "cold start", that is with no prior knowledge of the satellite locations. Those with an on-board battery backed memory of recent satellite locations can be quite fast to start up, but if the battery dies they start all over every time.
Which is how they really get confused when you turn them off, board an airplane to fly across the country and then turn them back on again - they expect to still be somewhere near where they were. Takes them a while to realize "you ain't there any more" 
Thank you,for that information.
But what happen when i 'Hot Start" Gps.?
I'm just curious to know
Thanks again
"hot start" is when the GPS knows about where it is and what satellites should be visible since it was just on recently. That allows it to lock on faster since it knows what it is looking for and it already has some of the current information. Different GPS seem to have significantly different times for startup. My old Magellan was notorious for taking quite a while to figure out where it was if it had been off for 6 months or so. My Garmin seems to wake up much faster and figure out where it is (this is with both of them having a good view of the sky).