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mikalhart / TinyGPSPlus

A new, customizable Arduino NMEA parsing library
http://arduiniana.org
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Time/Date sometimes erroneously reported as "valid"/"updated" #5

Closed mikalhart closed 9 years ago

mikalhart commented 10 years ago

Certain modules, prior to getting a fix, report NMEA strings like this:

$GPGGA,,,,,,, …

Since they have valid checksums, the current implementation sets the time and date fields to "valid" and "updated", even though they clearly are not really either. (Courtesy Alan Adamson.)

denravonska commented 10 years ago

I also just noticed that our Telit SL869 module seems to report an old timestamp after booting if no antenna is connected. Perhaps it might be best to rely on the position quality before extracting the date and time. This invalidates my previous #2 issue. Maybe just using a lower threshold (navigated?) is enough?

mikalhart commented 9 years ago

Unfortunately, there are other modules which report a perfectly useful date and time long before the module sees enough satellites to generate a proper position fix. I would hate to artificially mark these as invalid just to be friendly to SL869 users.