get lat,lon from NMEA message of GPS module GYSFDMAXB , GYSFFMANC

read_NMEA_tst.py

#!python3
# read_NMEA_tst.py
# hardware : GYSFFMANC :GYSFDMAXB : MT3333 : https://akizukidenshi.com/catalog/g/gK-13850/
# only for JAPAN

TIME_ZONE = 9

fLat = 0
fLon = 0
fAlt = 0

fHour = 0
fMinute = 0
fSec = 0

fYear = 0
fMonth = 0
fDay = 0


def degmin2deg(x):
	# ddmm.mmmm to dd.ddddd , sexagesimal to decimal
	dd = float(int(x/100))
	m = x - dd*100
	fd = m/60
	deg = dd + fd
	return deg

def sep_hourminsec(s):
	sH = s[0:2]
	sM = s[2:4]
	sS = s[4:]
	fHour = float(sH) + TIME_ZONE
	fMinute = float(sM)
	fSec = float(sS)
	fADay = 0
	if fHour >= 24:
		fHour -=24
		fADay += 1 

	return fHour,fMinute,fSec,fADay

def str2float(s):
	x = float(s)
	if x==float('nan'):
		x=0
	return(x)

def process_GPGGA(s):
	ls = s.split(',')
	sTim = ls[1]
	sLat = ls[2]
	sNS =  ls[3]
	sLon = ls[4]
	sWE =  ls[5]
	sQua = ls[6]
	sNoS = ls[7]
	sHEr = ls[8]
	sAlt = ls[9]
	sUnA = ls[10]
	sGAl = ls[11]
	sUnG = ls[12]
	sDgp = ls[13]
	sDid = ls[14]
	if sLat == '' or sNS =='S' or sWE =='W':
    # not JAPAN
		return 0,0,0,0,0,0,0
	fLat = degmin2deg(str2float(sLat))
	fLon = degmin2deg(str2float(sLon))
	fAlt = str2float(sAlt)
	fHour,fMinute,fSec,fADay = sep_hourminsec(sTim)
	return fLat,fLon,fAlt,fHour,fMinute,fSec,fADay
	
def switch_process(s):
	global fLat
	global fLon
	global fAlt
	global fHour
	global fMinute
	global fSec
	if s.startswith('$GPGGA'):
		fLat,fLon,fAlt,fHour,fMinute,fSec,fADay = process_GPGGA(s)

#----- test ------

tststr = '$GPGGA,055045.000,,,,,0,0,,,M,,M,,*49'

switch_process(tststr)
print(fLat,fLon,fAlt,fHour,fMinute,fSec)


tststr = '$GPGGA,060610.000,3943.5180,N,14039.0526,E,1,5,3.14,49.2,M,37.0,M,,*6A'

switch_process(tststr)
print(fLat,fLon,fAlt,fHour,fMinute,fSec)