Know your gridsquare at all times!
Launch gpsd by running your favorite map program or
/usr/libexec/navicore-gpsd-helper
Then run
python gpsdll2mh.py
#!/usr/bin/python
# gpsdll2mh.py
#
# G1OGY 20081102
#
# `gpsdll2mh.py` is a `gpsd' [http://gpsd.berlios.de] console-client which
# prints Maidenhead LOCATOR at user-determined, arbitary, even-number
# precision; (GPS precision max=52 - it gets quite silly long before that).
#
# PREREQUISITES: this program requires access to a running `gpsd' daemon
# (with a GPS receiver attached and functional).
#
# `gpsdll2mh.py` is intended for 'Rover-style' operation ( WAB, WAS, perhaps)
# so that one's 'new' locator can be sent as soon as it becomes apparant.
# It will also assist in calculating a (static) locator to a greater
# precision for microwave dish aiming purposes.
#
#
#
# Command line args are supported to select Locator precision (default=6);
# repeat frequency; server:port
#
#
# Command line (console) usage:
#
# python gpsdll2mh.py [[[precision] [repeat]] [server:port]]] <additive>
#
# like: python gpsdll2mh.py 10 30 (on a linux laptop running gpsd)
# or : python gpsdll2mh.py 10 30 192.168.1.99:2947 (on a (Windows) laptop connecting
# to linux server on standard port)
# so: 10-char locator evey 30 seconds
#
#
# Credits:
# The Lat/Long to Maidenhead part of this program is a rework of an original script by
# Dan Jacobson -- http://jidanni.org/geo/maidenhead/ ; latterly updated by Rene Kanter.
#
## lonlat2maidenhead -- long/lat to Maidenhead grid calculator not limited to 6 characters
## Created On : Sat Mar 15 03:54:08 2003
## rkanters 2004.2.20 version ll2mh
#
# Thank you, gentlemen.
#
#
# gpsdll2mh.py Program code
# -------------------------
# get modules
import re, sys, string
from time import sleep
from socket import *
# Set variables (defaults)
gpsdHost = 'localhost'
gpsdPort = 2947 # gpsd default (IANA)
gpsdCall = ['p'] # fixed gpsd command for 'position'
# print usage at default (no args) start ('cos of cheap way to do command-line args)
print '\n*********************************************** ************************'
print '\n',sys.argv[0],
# Ah! running with no args
if len(sys.argv)<2:
print "Running : 6-char LOC, 5 sec rptr, `gpsd' is local, default port \n"
print 'Usage:'
print ' ',sys.argv[0],'[[[LOC Precision] [Repeat delay]] [Server:port]]]\n'
# Abort!
print '\nINFO :: ** Ctrl-C to stop **\n\n'
# Ah! Now have args to chobble...
# validate the input precision value: must have an even number
if len(sys.argv)>1:
loclen=int(sys.argv[1])
if loclen<2 or loclen%2!=0:
sys.stderr.write('ERROR :: Locator precision requested must be an even number \n\n')
sys.exit(87)
else:
loclen=6 # why report only Square? (won't often change unless you're in a 'plane!)
# if only sqare is needed then '4' on cmd line
maxn=loclen/2 # program constant
# grab or set repeat value
if len(sys.argv)>2:
snooze=int(sys.argv[2])
else:
snooze = 5 # seconds
# gpsd network server
if len(sys.argv)>3:
sp = sys.argv[3].split(":")
gpsdHost=sp[0]
gpsdPort=int(sp[1])
print 'INFO :: Connecting to : ', gpsdHost,':',gpsdPort,'\n'
# Networking
# create local socket
gpsdSock = socket(AF_INET, SOCK_STREAM)
# connect to gpsd daemon
try:
gpsdSock.connect((gpsdHost, gpsdPort))
except Exception, e:
print " FATAL ERROR :: Cannot connect to `gpsd'!\n"
print "Is `gpsd' running? Is your server:port address correct?\n"
print "System message ::" , e ,'\n'
# send position query, receive response and calculate LOCATOR
# ~persevere~ if daemon is recalcitrant
try:
while 1:
for Query in gpsdCall:
gpsdSock.send(Query)
data = gpsdSock.recv(32)
if len(data)<12:
break
latlong = data[7:]
A=ord('A') # set a base value for the calcs.
# Following commented code originally allowed for manual entry of the lat/long values -
# I'll revisit this sometime so that there's a stand-alone option.
# run the prog with a switch - it sits and waits for input: LAT.###### <space> LONG.###### [CR]
# JIC the OPS have only a handheld GPS or Sat-Nav system available.
##
### while 1:
### line=sys.stdin.re adline()
### if not line: break
### ll=re.findall(r'([-0-9.]+)\s+([-0-9.]+)',line)
##
ll=re.findall(r'([-0-9.]+)\s+([-0-9.]+)',latlong)
if ll:
for x,y in ll:
lat=float(x)
lon=float(y)
else:
sys.stderr.write(sys.argv[0]+': ERROR :: Cannot determine LAT / LONG. Is ''`gpsd'' running?\n\n')
sys.exit(44)
if -180<=lon<180: pass
else:
sys.stderr.write('ERROR :: longitude must be -180<=lon<180\n\n')
sys.exit(32)
if -90<=lat<90: pass
else:
sys.stderr.write('ERROR :: latitude must be -90<=lat<90\n\n')
sys.exit(33) # can't handle north pole, sorry, [A-R]
lon=(lon+180.0)/20 # scale down and set up for first digit
lat=(lat+90.0)/10
mhloc=""
i=0
while i<maxn:
i+=1
loni=int(lon)
lati=int(lat)
if i%2:
mhloc+=chr(A+loni)+chr(A+lati)
lon=(lon-loni)*10
lat=(lat-lati)*10
else:
mhloc+=str(loni)+str(lati)
lon=(lon-loni)*24
lat=(lat-lati)*24
# print lat/long 'cos a short (<12) locator won't update much
# (unless you've got the hammer down)
print 'Lat / Long: ', latlong, 'Locator: ', mhloc, '\n' # main output
sleep(snooze) # repeat delay
# Close down
except KeyboardInterrupt: # inhibits the traceback on exit
gpsdSock.shutdown(1)
gpsdSock.close()
# returns the grid square, to the precision given, that contains the given point.
#
# TO DO
# DONE! Trap no valid GPS Data - if GPS device is unplugged gpsd continues but provides `?'
# DONE! Trap no gpsd daemon - can't connect
# Esoteric...
# keep count (and display on close) of all Fields [IO, JO, JN], Squares [JO01, IO91, JP63]
# and Sub-Squares [JO01BR, JO01HQ] traversed on the journey.
# 3 counters inside. Storage?? mySQL-Lite??
# print 'em ???
You can download the code above here http://www.g1ogy.com/projects/gps/gpsdll2mh.py or here http://www.g1ogy.com/projects/gps/gpsdll2mh.shtml
A simple script to run this would be
/usr/libexec/navicore-gpsd-helper&
sleep 15
python gpsdll2mh.py
Or if you want the extra bells such as the compass from GPSJinni
GPSJinni&
sleep 15
python gpsdll2mh.py