# -*- coding: iso-8859-15 -*- # $Id: NMEAParser.py 244 2006-02-05 20:36:41Z arista $ # Copyright Aapo Rista 2005-2006 #FIXME: Change parser so it returns dictionary of values instead of updating position object class NMEAParser: """NMEAParser gets one NMEAString as a parameter and returns currently nothing but updates the Position-object. In the future NMEAParser will return a dictionary of parsed values. Currentry there are functions for '$GPRMC', '$GPGGA', '$GPGSA', '$GPGSV', '$GPGLL' and '$GPVTG' NMEA-senteces.""" id = u'$Id: NMEAParser.py 244 2006-02-05 20:36:41Z arista $' # DO NOT modify Id-string pos = None sat_state = {} # Last parsed state of satellites {'sat_id' : [Elevation, Azimuth, SignalNoiseRatio]} sat_state_temp = {} # State currently being parsed def __init__(self, pos): # To be removed try: # Parse revision and last change date ida = self.id.split(" ") self.revision = ida[2] self.lastchangeddate = ida[3] except: self.revision = u'undefined' self.lastchangeddate = u'undefined' self.pos = pos sentences_to_parse = {'GPRMC':1, 'GPGGA':0, 'GPGSA':0, 'GPGSV':0, 'GPGLL':0, 'GPVTG':0} #senteces2parse = ('$GPRMC') def checksum(self, nmealine): """Calculate checksum of given NMEA-sentence""" # Reject nmealines shorter than 5 bytes or having not '*' if len(nmealine) < 5 or nmealine[-4] != '*': return None nmeastr = nmealine[1:-4] chksumstr = line[-3:].rstrip() chksum = 0 for i in range(0, len(nmeastr)): chksum ^= ord(nmeastr[i:i+1]) # FIXME: return true or false if checksumstr == ("%02X" % chksum): #print 'OK "%s" = "%02X"' % (chkstr, chksum) return True else: #print 'FAIL LINE %d: "%s" != "%02X"' % (i, checksumstr, chksum) return False def _parseNMEALatLon(self, lat, l1, lon, l2): """Parse location from NMEA sentence. (6027.1954,N,02512.2171,E)""" try: # Convert lat/lon string to float latitude = float(lat[0:2]) + (float(lat[2:4] + "." + lat[5:9])/60) longitude = float(lon[0:3]) + (float(lon[3:5] + "." + lon[6:10])/60) if l1 is "S": latitude = -latitude if l2 is "W": longitude = -longitude #latitude = float("%.6f" % latitude) #longitude = float("%.6f" % longitude) return latitude, longitude except: return (None, None) def parseGPRMC(self, NMEAline): """Parse GPRMC Sentence (Position and time)""" # $GPRMC,195640.000,A,6027.1954,N,02512.2171,E,7.57,255.79,290505,,*0C # $GPRMC,195641.000,A,6027.1948,N,02512.2129,E,7.31,254.13,290505,,*00 # $GPRMC,195642.000,A,6027.1941,N,02512.2088,E,7.32,253.44,290505,,*06 # FIXME: is this NMEA 2.3 compatible? if (NMEAline.count(",") == 11): # Expect 11 ','-delimiters (NMEA 2.2) (GPRMC,hhmmssss,status,lat,l1,lon,l2,speed_knots,course,ddmmyy,mvd,mdr_cs)=NMEAline.split(",") elif (NMEAline.count(",") == 12): # Expect 12 ','-delimiters (NMEA 2.3) (GPRMC,hhmmssss,status,lat,l1,lon,l2,speed_knots,course,ddmmyy,mvd,mdr,fix_cs)=NMEAline.split(",") else: print "Invalid GPRMC"; return self.pos.gpsstatus = status self.pos.set_time(hhmmssss) self.pos.set_date(ddmmyy) self.pos.set_speed_knots(speed_knots) self.pos.set_course(course) if (status is 'A' and lat is not "" and lon is not ""): latitude, longitude = self._parseNMEALatLon(lat, l1, lon, l2) self.pos.set_lat_lon(latitude, longitude) def parseGPGGA(self, NMEAline): """Parse GPGGA Sentence (Fix data)""" # $GPGGA,195640.000,6027.1954,N,02512.2171,E,1,09,0.9,34.9,M,,,,0000*3C # $GPGGA,195641.000,6027.1948,N,02512.2129,E,1,09,0.9,35.5,M,,,,0000*30 # $GPGGA,195642.000,6027.1941,N,02512.2088,E,1,09,0.9,36.0,M,,,,0000*36 # $GPGGA,093454.108,,,,,0,00,,,M,,,,0000*33 if (NMEAline.count(",") == 14): # Expect 14 ','-delimiters (GPGGA,hhmmssss,lat,l1,lon,l2,q,xx,pp,ab,M,cd,M,xx,nnnn)=NMEAline.split(",") self.pos.set_time(hhmmssss) #if (hhmmssss is not ""): # self.pos.time = hhmmssss if (lat is not "" and lon is not ""): latitude, longitude = self._parseNMEALatLon(lat, l1, lon, l2) self.pos.set_lat_lon(latitude, longitude) else: print "Invalid GPGGA"; def parseGPGSA(self, NMEAline): """Parse GPGSA Sentence (Active satellites).""" # $GPGSA,A,3,09,18,22,29,11,28,07,26,05,,,,2.1,0.9,1.9*37 # $GPGSA,A,3,09,18,22,29,11,28,07,26,05,,,,2.1,0.9,1.9*37 # $GPGSA,A,3,09,18,22,29,11,28,07,26,05,,,,2.1,0.9,1.9*37 if (NMEAline.count(",") == 17): # Expect 17 ','-delimiters (GPGSA,m1,m2,s1,s2,s3,s4,s5,s6,s7,s8,s9,s10,s11,s12,PDOP,HDOP,VDOPcs) = NMEAline.split(",") VDOP,cs = VDOPcs.split("*") self.pos.PDOP = PDOP self.pos.HDOP = HDOP self.pos.VDOP = VDOP def parseGPGSV(self, NMEAline): """Parse GPGSV Sentence (Satellites in view).""" # $GPGSV,3,1,09,09,47,278,32,07,47,122,39,26,43,196,31,28,39,072,32*70 # $GPGSV,3,2,09,29,32,186,34,18,21,282,32,22,21,316,32,11,15,039,23*79 # $GPGSV,3,3,09,05,11,239,31*4F #FIXME: nothing resets self.pos.sat_fix if fix is lost if (NMEAline.count(",") >= 5): # Remove checksum from the end of the line NMEAline,cs = NMEAline.split("*") tokens = NMEAline.split(",") (GPRSV,seqcnt,seqnum,satellites) = tokens[:4] self.pos.satellites = satellites endline = NMEAline.split(",")[4:] # Evaluate all satellites from endline while len(endline) > 0: satid = endline.pop(0) elevation = endline.pop(0) azimuth = endline.pop(0) snratio = endline.pop(0) self.sat_state_temp[satid] = [elevation, azimuth, snratio] if seqcnt == seqnum: self.sat_state = {} self.sat_state = self.sat_state_temp self.sat_state_temp = {} sv = 0 # count satellites with fix for satid in self.sat_state.keys(): if self.sat_state[satid][2] is not '': sv = sv + 1 self.pos.sat_fix = sv def parseGPGLL(self, NMEAline): """Parse GPGLL Sentence (Position).""" # $GPGLL,6027.1956,N,02512.3605,E,215948.000,A*30 # $GPGLL,6027.1957,N,02512.3606,E,215949.000,A*33 # $GPGLL,6027.1958,N,02512.3608,E,215950.000,A*3A # FIXME: check NMEA 2.3 compatibility if (NMEAline.count(",") == 6): # Expect 6 ','-delimiters (GPGGA,lat,l1,lon,l2,hhmmssss,status_cs)=NMEAline.split(",") (status, cs) = status_cs.split("*") self.pos.gpsstatus = status self.pos.set_time(hhmmssss) if (status is 'A' and lat is not "" and lon is not ""): latitude, longitude = self._parseNMEALatLon(lat, l1, lon, l2) self.pos.set_lat_lon(latitude, longitude) def parseGPVTG(self, NMEAline): """Parse GPVTG Sentence (Course over ground).""" # $GPVTG,213.81,T,,M,1.19,N,2.2,K*60 # $GPVTG,78.97,T,,M,0.72,N,1.3,K*56 # $GPVTG,66.09,T,,M,1.50,N,2.8,K*57 # FIXME: check NMEA 2.3 compatibility if (NMEAline.count(",") == 8): # Expect 8 ','-delimiters (NMEA 2.2) (GPVTG,course_true,T,course_magn,M,speed_knots,N,speed_kmph,K_cs)=NMEAline.split(",") elif (NMEAline.count(",") == 9): # Expect 8 ','-delimiters (NMEA 2.3) (GPVTG,course_true,T,course_magn,M,speed_knots,N,speed_kmph,K,fix_cs)=NMEAline.split(",") #(K, cs) = K_cs.split("*") # unnecessary self.pos.set_speed_kmph(speed_kmph) self.pos.set_course(course_true) #To be changed to general parser def parse_line(self, NMEAline): NMEAname = NMEAline[0:6] if (NMEAname == "$GPRMC"): self.parseGPRMC(NMEAline) #elif (NMEAname == "$GPGGA"): # self.parseGPGGA(NMEAline) elif (NMEAname == "$GPGSA"): self.parseGPGSA(NMEAline) #elif (NMEAname == "$GPGSV"): # self.parseGPGSV(NMEAline) #elif (NMEAname == "$GPGLL"): # self.parseGPGLL(NMEAline) #elif (NMEAname == "$GPVTG"): # self.parseGPVTG(NMEAline)