[ntp:questions] Using mode byte for Accord GPS Clock
venu gopal
neo.venu at gmail.com
Tue Dec 4 11:01:55 UTC 2007
Hi all,
The 'mode' field a.k.a 'ttl' for NMEA reference driver is used
to select the NMEA
sentence. I cannot use the unused fudge flags 'flag1' and 'flag4'
as they are unavailable
before the serial port is opened. Somehow I have to select both
the baudrate and the
NMEA sentence from the 'mode' field itself.
Currently 'mode' field with values 0,1,2,4 are used in NMEA
reference driver with default
baudrate of 4800. Can I use the 'mode' field with value 8 and the
rest of the three bits to
select NMEA sentence.
1. Mode value 8 => 9600, GPXXX
2. Mode value 9 => 9600, GPRMC
3. Mode value 10 => 9600, GPGGA
4. Mode value 11 => 9600, GPGLL
5. Mode value 12 => 9600, GPZDG (Accord custom NMEA sentence)
6. Mode value 13 => 9600, GPZDA
So the 4th bit of the 'mode' field is used to check if baudrate
needs to be changed,
while the rest of the 3 bits denote the NMEA sentence to be selected.
Comments plz...
Venu.
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