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List:       gpsd-dev
Subject:    [Gpsd-dev] No date in your GPS output
From:       esr () snark ! thyrsus ! com (Eric S !  Raymond)
Date:       2005-06-21 21:47:58
Message-ID: 200506212147.j5LLlwh9006692 () snark ! thyrsus ! com
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I think I found the reason you're not seeing time-date.  If I'm
correct, it's a side effect of a change I made in in 2.25 to make
gpsd independent of the system clock, so it can be used to *set* the
system clock.

You'll get a zero time/date from a GGA or GLL that has never been
preceded by an RMC or ZDA.  The reason: gpsd doesn't yet know what
year it is.  Before 2.25 I grabbed this information from the 
system clock, but this gives unhappy results if the system clock
is inaccurate -- especially if it has been recently zeroed, in which
case you'll get not just the wrong year but the wrong *century*!

Rather than pretending to know something from the GPS that it doesn't,
I have elected to make gpsd confess that it doesn't have a valid
timestamp in this situation.  It should only last at most one cycle,
until the daemon picks up a valid GPRMC sentence.

I'll shortly check in a change that ensures the time-date field is ?
rather than 0 in this situation.
-- 
		<a href="http://www.catb.org/~esr/">Eric S. Raymond</a>

"...The Bill of Rights is a literal and absolute document. The First
Amendment doesn't say you have a right to speak out unless the
government has a 'compelling interest' in censoring the Internet. The
Second Amendment doesn't say you have the right to keep and bear arms
until some madman plants a bomb. The Fourth Amendment doesn't say you
have the right to be secure from search and seizure unless some FBI
agent thinks you fit the profile of a terrorist. The government has no
right to interfere with any of these freedoms under any circumstances."
	-- Harry Browne, 1996 USA presidential candidate, Libertarian Party

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