RTC information on Ultimate GPS Shield - RTC Battery

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hgrapentin
 
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RTC information on Ultimate GPS Shield - RTC Battery

Post by hgrapentin »

Hello,
just started playing around with that nice shield on Ardunio UNO - adapted the example adafruit SD logger (shield_sdlog) code to have up to 999 data files available when starting the device as I did not find a way to name the files with a time stamp like 05121038.txt for 12th of May 10:38 even if I have no NMEA from GPS yet.

Now trying to figure out the sense of the RTC backup battery. Can I grab from anywhere the stored time before I get the information from the NMEA data to use it for the file name creation.

Many thanks for any help :)

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adafruit_support_mike
 
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Re: RTC information on Ultimate GPS Shield - RTC Battery

Post by adafruit_support_mike »

The RTC backup battery keeps the clock in the GPS module running while power is disconnected. It also keeps the GPS system's satellite position tables active in memory, which makes it easier for the module to get a fix when it gets power again.

You should be able to get date and time information from the $GPRMC sentence before the module gets a position fix.

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hgrapentin
 
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Re: RTC information on Ultimate GPS Shield - RTC Battery

Post by hgrapentin »

Ok - clear now.
Thanks!

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