[ntp:questions] Best NMEA sentence

Hal Murray hmurray at megapathdsl.net
Sat Feb 20 21:52:41 UTC 2016

> Is there a generally accepted NMEA ?best sentence? for use with ntp? For
> example, I?ve seen GPRMC, GPGGA and GPZDA all individually recommended in
> Google searches, variously at 4800 or 9600 baud. Will whatever sentence I
> choose ultimately give the same results?

Do you have a specific brand/model in mind?  (or chip set?)

Simple answer is use GPRMC.  Turn off the others if you can.

GPGGA doesn't include the date.  That might make a difference when booting after power loss if your clock battery is dead.  GPZDA doesn't include a valid status marker.

The other consideration is that the length of some sentences changes depending on how many satellites are visible and working.  If the cluster of sentences starts at the same offset each second and the one you pick is after one that changes the length, the offset will vary by the length and baud rate.  So pick one that is early in the cluster.

These are my opinions.  I hate spam.

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