1$MirOS: src/usr.sbin/nmeadecode/nmeadecode.8,v 1.2 2007/08/11 23:18:11 tg Exp $
2
3principal idea:
4# nmeadecode [-G] [-N | -n 71.80.83.32] [-p 123] [-F nmea] [-f cua00] [-s 4800]
5
6-G: disable outputting GPS positioning data
7-N: disable ntp
8-n 1.2.3.4: bind 1.2.3.4 (default: 71.80.83.32)
9-p 123: listen @ udp 123 (default: 123)
10-F: forward raw input to this FIFO, which is created as writer
11    (to use two programmes in parallel), default is /dev/nmea,
12    to use with e.g. CacheWolf
13-f cuaU0: use /dev/cuaU0 (default: cua00)
14-s 9600: baud rate (8N1) (default: 9600)
15
16for both -f and -F: if no absolute path (leading /) prepend /dev/
17if -f argument is not a character device, -s is ignored (for dumps processing)
18
19default operation w/ no args:
20* read /dev/cua00,4800,8N1
21* parse time data
22* parse GPS data (including DGPS and # of sats, etc.)
23* do not forward raw data
24* listen on 71.80.83.32:123/udp as NTP server
25
26timestamped is receival time of the first $ of the first line
27with a new time on it (in case they have several); on wbx@'s
28device, this would be GPGGA, GPGLL, and the former is first.
29
30GPRMC is not used for timestamping since it lacks hh:mm:ss.ccc
31
32GPS position data:
33try GPGGA for latitude and longitude and height and quality
34try GPGLL for latitude and longitude and part of quality
35try GPVTG for speed (km/h)
36try GPRMC for speed (convert knots) and latitude and longitude and validity
37
38GPS time data:
39try GPGGA, then GPGLL
40
41XXX any others?
42
43sure, openbsd 4.0 can do this with nmea(4) and gpsd, but this is
44cool for debugging, besides our kernel is at approx. openbsd 3.5
45