Getting GPS Time?

Hardware (GPS, accelerometer, etc.)
#1

I need to get very accurate time across multiple devices. I am currently getting time with NTP, which is so-so.

However, many devices have GPS — is it possible to get the GPS time, so that multiple devices could be doing things at the same time?

Here’s some discussion about it, suggesting that it might be possible in Objective C, which I know nothing about:

http://stackoverflow.com/questions/1444456/is-it-possible-to-get-the-atomic-clock-timestamp-from-the-iphone-gps

#2

what about using a server that will make sure that you have the same timestamp for every device?

#3

Huh. You mean, don’t worry about the exact time, just have everyone get the time from the same source. Which is, in theory, what NTP is doing, too…but a million times easier. Huh.

#4

it really depends on what you are actually trying to do but this would be the general approach I would be using. 

instead of trying to sync many clients to the have the same time, I would just make my own (or use a common) clock instead. 

make one call when you start running the app and from there use relative time.

#5

what about using a server that will make sure that you have the same timestamp for every device?

#6

Huh. You mean, don’t worry about the exact time, just have everyone get the time from the same source. Which is, in theory, what NTP is doing, too…but a million times easier. Huh.

#7

it really depends on what you are actually trying to do but this would be the general approach I would be using. 

instead of trying to sync many clients to the have the same time, I would just make my own (or use a common) clock instead. 

make one call when you start running the app and from there use relative time.