def initGPS (speed,format):
try:
#GPS RESET, GPIO 18 configured as Output, value is Cleared to '0'
#GPS held in RESET
GPIO.setIOdir(18,1,1)
#GPS RESET, GPIO 18 configured as Output, value is Cleared to '0'
#GPS is running
GPIO.setIOvalue(18, 0)
#Init Serial Port Settings
res = GSM864QP_SER.init_parameters(speed,format)
MOD.sleep(10)
res = GSM864QP_SER.send_50PIN('\r\n')
#Disable all NMEA output sentences
#NMEA GPS sentences will only transmit when polled by CW20.update() method
res = GSM864QP_SER.send_50PIN('$PNMRX103,ALL,0\r\n')
## Start timeout timer
CW20_timerA = timers.timer(0)
CW20_timerA.start(2)
# Empty Serial Port Buffer
res = "junk"
while(res != ""):
res = GSM864QP_SER.read_50PIN()
if (CW20_timerA.isexpired()):
break
except:
print 'Script encountered an exception.'
print 'Exception Type: ' + str(sys.exc_type)
print 'MODULE -> CW20'
print 'METHOD -> initGPS(' + speed + ',' + format + ')'
return
def update():
# This function receives ALL NMEA sentences and parses out data fields
# You might need to add more properties to this class to get more data out of the update method
# You MUST have the jumpers on the external header connecting Pin(49 & 47) and Pin(45 & 43)
try:
#Get NMEA RMC sentence
NMEA = ''
NMEA_list = ''
GPSdata.GPGGA = ''
GPSdata.GPGLL = ''
GPSdata.GPGSA = ''
GPSdata.GPGSV = ''
GPSdata.GPRMC = ''
GPSdata.GPZDA = ''
GPSdata.GPVTG = ''
## Start timeout timer
CW20_timerA = timers.timer(0)
CW20_timerA.start(10)
#Clear Buffer - NMEA Commands are disabled in initReceiver
res=''
while(res != ''):
res = GSM864QP_SER.read_50PIN()
if (CW20_timerA.isexpired()):
break
#Enable NMEA sentence to transmit once every 10 seconds
res = GSM864QP_SER.send_50PIN('$PNMRX103,ALL,10\r\n')
NMEA = ''
while(1):
res = GSM864QP_SER.read_50PIN()
NMEA = NMEA + res
lenNMEA = len(NMEA)
pos1 = NMEA.rfind('GPVTG',0)
pos2 = NMEA.rfind('\r\n',pos1)
if ((pos1 >=0) and (pos2 >= pos1)):
#NMEA data is complete
break
if (CW20_timerA.isexpired()):
GPSdata.GPGGA = 'TIMEOUT\r\n'
GPSdata.GPGLL = 'TIMEOUT\r\n'
GPSdata.GPGSA = 'TIMEOUT\r\n'
GPSdata.GPGSV = 'TIMEOUT\r\n'
GPSdata.GPRMC = 'TIMEOUT\r\n'
GPSdata.GPZDA = 'TIMEOUT\r\n'
GPSdata.GPVTG = 'TIMEOUT\r\n'
return
NMEA_list = NMEA.split('\r\n')
for x in NMEA_list:
sentence_list = x.split(',')
if (sentence_list[0] == '$GPGGA'):
GPSdata.GPGGA = str(x) + '\r\n'
elif (sentence_list[0] == '$GPGLL'):
GPSdata.GPGLL = str(x) + '\r\n'
elif (sentence_list[0] == '$GPGSA'):
GPSdata.GPGSA = str(x) + '\r\n'
elif (sentence_list[0] == '$GPGSV'):
GPSdata.GPGSV = GPSdata.GPGSV + str(x) + '\r\n'
elif (sentence_list[0] == '$GPRMC'):
GPSdata.GPRMC = str(x) + '\r\n'
elif (sentence_list[0] == '$GPZDA'):
GPSdata.GPZDA = str(x) + '\r\n'
elif (sentence_list[0] == '$GPVTG'):
GPSdata.GPVTG = str(x) + '\r\n'
#Disable all NMEA Sentences
res = GSM864QP_SER.send_50PIN('$PNMRX103,ALL,0\r\n')
while(res != ''):
res = GSM864QP_SER.read_50PIN()
if (CW20_timerA.isexpired()):
break
except:
print 'Script encountered an exception.'
print 'Exception Type: ' + str(sys.exc_type)
print 'MODULE -> CW20'
print 'METHOD -> update()'
GPSdata.GPGGA = 'EXCEPTION\r\n'
GPSdata.GPGLL = 'EXCEPTION\r\n'
GPSdata.GPGSA = 'EXCEPTION\r\n'
GPSdata.GPGSV = 'EXCEPTION\r\n'
GPSdata.GPRMC = 'EXCEPTION\r\n'
GPSdata.GPZDA = 'EXCEPTION\r\n'
GPSdata.GPVTG = 'EXCEPTION\r\n'
return