Technical information

Format of the NMEA 0183 String (RMC)
The NMEA String is a sequence of 65 ASCII characters starting with the ‘$’
character and ending with the characters CR (carriage return) and LF (line-feed). The
format is:
$GPRMC,hhmmss.ss,A,bbbb.bb,n,lllll.ll,e,0.0,0.0,ddmmyy,0.0,a*hh<CR><LF>
The letters printed in italics are replaced by ASCII numbers or letters whereas the
other characters are part of the time string. The groups of characters as defined below:
$ start character (ASCII-Code 24h)
sending with one bit occuracy at change of second
hhmmss.ss the current time:
hh hours (00..23)
mm minutes (00..59)
ss seconds (00..59, or 60 while leap second)
ss fractions of seconds (1/10 ; 1/100)
A Status (A = time data valid)
(V = time data not valid)
bbbb.bb latitude of receiver position in degrees
leading signs are replaced by a space character (20h)
n latitude, the following characters are possible:
‘N’ north of equator
‘S’ south d. equator
lllll.ll longitude of receiver position in degrees
leading signs are replaced by a space character (20h)
e longitude, the following characters are possible:
‘E’ east of Greenwich
‘W’ west of Greenwich
ddmmyy the current date:
dd day of month (01..31)
mm month (01..12)
yy year of the century (00..99)
a magnetic variation
hh checksum (EXOR over all characters except ‘$’ and ‘*’)
<CR> carriage-return; ASCII-Code 0Dh
<LF> line-feed; ASCII-Code 0Ah
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