#!/usr/bin/env python # -*- coding: UTF-8 -*- """ Open GPS Daemon - Abstract parser class NMEA parser taken from pygps written by Russell Nelson Copyright, 2001, 2002, Russell Nelson Copyright permissions given by the GPL Version 2. http://www.fsf.org/ (C) 2008 Rod Whitby (C) 2008 Daniel Willmann (C) 2008 Openmoko, Inc. GPLv2 """ __version__ = "0.0.0" import math import string import time import dbus from gpsdevice import GPSDevice import logging logger = logging.getLogger('ogpsd') DBUS_INTERFACE = "org.freesmartphone.GPS" class NMEADevice( GPSDevice ): def __init__( self, bus, gpschannel ): super( NMEADevice, self ).__init__( bus ) self.buffer = "" self.gpschannel = gpschannel self.gpschannel.setCallback( self.parse ) self.prn = range(12) self.elevation = range(12) self.azimuth = range(12) self.ss = range(12) self.used = range(12) self.date = '000000' self.time = '000000' self.timestamp = 0 self.mode = 0 self.lat = 0.0 self.lon = 0.0 self.altitude = 0.0 self.track = 0.0 self.speed = 0.0 self.in_view = 0 def parse( self, data ): self.buffer += data while True: try: line, self.buffer = self.buffer.split( "\r\n", 1 ) except: break else: result = self.handle_line( line.strip() ) if result: logger.debug( result ) def checksum(self,sentence, cksum): csum = 0 for c in sentence: csum = csum ^ ord(c) return "%02X" % csum == cksum #$GPGGA,000032.997,0000.0000,N,00000.0000,E,0,00,50.0,0.0,M,,.j...«.æ.ÆV.æ.ÆV.æ.|.VÖL²4jj.h..00032.997,V,0000.0000,N,00000.0006 #Lat: 0.000000 Lon: 0.000000 Alt: 0.000000 Sat: 0 Mod: 1 Time: 11/26/2000 00:00:31 #$GPGGA,000033.997,0000.0000,N,00000.0000,E,0,00,50.0,0.0,M,,,,0000*3C def do_lat_lon(self, words): if not words[0]: return if words[0][-1] == 'N': words[0] = words[0][:-1] words[1] = 'N' if words[0][-1] == 'S': words[0] = words[0][:-1] words[1] = 'S' if words[2][-1] == 'E': words[2] = words[2][:-1] words[3] = 'E' if words[2][-1] == 'W': words[2] = words[2][:-1] words[3] = 'W' if len(words[0]): lat = string.atof(words[0]) frac, intpart = math.modf(lat / 100.0) lat = intpart + frac * 100.0 / 60.0 if words[1] == 'S': lat = -lat self.lat = lat if len(words[2]): lon = string.atof(words[2]) frac, intpart = math.modf(lon / 100.0) lon = intpart + frac * 100.0 / 60.0 if words[3] == 'W': lon = -lon self.lon = lon #$GPRMC,024932.992,V,4443.7944,N,07456.7103,W,,,270402,,*05 #$GPRMC,024933.992,V,4443.7944,N,07456.7103,W,,,270402,,*04 # RMC - Recommended minimum specific GPS/Transit data # RMC,225446,A,4916.45,N,12311.12,W,000.5,054.7,191194,020.3,E*68 # 225446 Time of fix 22:54:46 UTC # A Navigation receiver warning A = OK, V = warning # 4916.45,N Latitude 49 deg. 16.45 min North # 12311.12,W Longitude 123 deg. 11.12 min West # 000.5 Speed over ground, Knots # 054.7 Course Made Good, True # 191194 Date of fix 19 November 1994 # 020.3,E Magnetic variation 20.3 deg East # *68 mandatory checksum def processGPRMC(self, words): self.do_lat_lon(words[2:]) self.date = words[8] day = string.atoi(self.date[0:2]) month = string.atoi(self.date[2:4]) year = 2000 + string.atoi(self.date[4:6]) self.time = words[0][0:6] hours = string.atoi(self.time[0:2]) minutes = string.atoi(self.time[2:4]) seconds = string.atoi(self.time[4:6]) self.timestamp = int(time.mktime((year,month,day,hours,minutes,seconds,-1,-1,-1))) if words[1] == 'V' or words[1] == "A": if words[6]: self.speed = string.atof(words[6]) if words[7]: self.track = string.atof(words[7]) self._updateCourse( 6, self.timestamp, self.speed, self.track, 0 ) #$GPGGA,024933.992,4443.7944,N,07456.7103,W,0,00,50.0,192.5,M,,,,0000*27 #$GPGGA,024934.991,4443.7944,N,07456.7103,W,0,00,50.0,192.5,M,,,,0000*23 # GGA - Global Positioning System Fix Data # GGA,123519,4807.038,N,01131.324,E,1,08,0.9,545.4,M,46.9,M, , *42 # 123519 Fix taken at 12:35:19 UTC # 4807.038,N Latitude 48 deg 07.038' N # 01131.324,E Longitude 11 deg 31.324' E # 1 Fix quality: 0 = invalid # 1 = GPS fix # 2 = DGPS fix # 08 Number of satellites being tracked # 0.9 Horizontal dilution of position # 545.4,M Altitude, Metres, above mean sea level # 46.9,M Height of geoid (mean sea level) above WGS84 # ellipsoid # (empty field) time in seconds since last DGPS update # (empty field) DGPS station ID number def processGPGGA(self,words): day = string.atoi(self.date[0:2]) month = string.atoi(self.date[2:4]) year = 2000 + string.atoi(self.date[4:6]) self.time = words[0][0:6] hours = string.atoi(self.time[0:2]) minutes = string.atoi(self.time[2:4]) seconds = string.atoi(self.time[4:6]) self.timestamp = int(time.mktime((year,month,day,hours,minutes,seconds,-1,-1,-1))) self.status = string.atoi(words[5]) self.satellites = string.atoi(words[6]) if self.status > 0: self.do_lat_lon(words[1:]) self.altitude = string.atof(words[8]) # FIXME: Mode self._updateFixStatus( self.status + 1 ) self._updatePosition( 15, self.timestamp, self.lat, self.lon, self.altitude ) #$GPGSA,A,1,,,,,,,,,,,,,50.0,50.0,50.0*05 #$GPGSA,A,1,,,,,,,,,,,,,50.0,50.0,50.0*05 # GSA - GPS DOP and active satellites # GSA,A,3,04,05,,09,12,,,24,,,,,2.5,1.3,2.1*39 # A Auto selection of 2D or 3D fix (M = manual) # 3 3D fix # 04,05... PRNs of satellites used for fix (space for 12) # 2.5 PDOP (dilution of precision) # 1.3 Horizontal dilution of precision (HDOP) # 2.1 Vertical dilution of precision (VDOP) # DOP is an indication of the effect of satellite geometry on # the accuracy of the fix. def processGPGSA(self,words): self.mode = string.atof(words[1]) for n in range(12): if words[n+2]: self.used[n] = 1 else: self.used[n] = 0 pdop = string.atof(words[14]) hdop = string.atof(words[15]) vdop = string.atof(words[16]) # FIXME: Mode... self._updateAccuracy( 7, pdop, hdop, vdop ) self._updateSatellites( (self.prn[n],self.used[n],self.elevation[n],self.azimuth[n],self.ss[n]) for n in range(12) ) #$GPGSV,3,1,09,14,77,023,,21,67,178,,29,64,307,,30,42,095,*7E #$GPGSV,3,2,09,05,29,057,,11,15,292,,18,08,150,,23,08,143,*7A #$GPGSV,3,3,09,09,05,052,*4B # GSV - Satellites in view # GSV,2,1,08,01,40,083,46,02,17,308,41,12,07,344,39,14,22,228,45*75 # 2 Number of sentences for full data # 1 sentence 1 of 2 # 08 Number of satellites in view # 01 Satellite PRN number # 40 Elevation, degrees # 083 Azimuth, degrees # 46 Signal strength - higher is better # # There my be up to three GSV sentences in a data packet def processGPGSV(self,words): num_sentences = string.atoi(words[0]) current_sentence = string.atoi(words[1]) self.in_view = string.atoi(words[2]) f = 3 n = (current_sentence - 1) * 4 # FIXME: Need to clear the rest of the entries up to 12 while n < self.in_view and f < len(words): if words[f+0]: self.prn[n] = string.atoi(words[f+0]) if words[f+1]: self.elevation[n] = string.atoi(words[f+1]) if words[f+2]: self.azimuth[n] = string.atoi(words[f+2]) if words[f+3]: self.ss[n] = string.atoi(words[f+3]) f = f + 4 n = n + 1 def processPGLOR(self,words): # FIXME: Do we do anything with this sentence? pass def handle_line(self, line): if line[0] == '$': line = string.split(line[1:-1], '*') if len(line) != 2: return # if not self.checksum(line[0], line[1]): # return "Bad checksum" words = string.split(line[0], ',') methodname = "process"+words[0] try: method = getattr( self, methodname ) except AttributeError: logger.error( "Line: %s" % line) return "Unknown sentence" else: try: method( words[1:] ) except Exception, e: logger.error( "Line: %s" % line) logger.error( "Error in %s method: %s" % ( methodname, e ) ) else: return "Not NMEA" #vim: expandtab