Demo Source Code
The Python source code of this demo is provided for reference purpose only.
uart_gps_demo.py:
''' Please make sure the NEO-6M is connected to the correct pins. The following table describes how to connect NEO-6M to the 40-pin header ----------------------------------------- Passive Buzzer___Pin Number_____Pin Name VCC 4 5 V Power GND 6 GND TXD 10 UART RX RXD 8 UART TX ---------------------------------------- ''' import sys import serial import time #Reference information of the GPGSA format. ''' Example 1 (GPS only): $GPGSA,M,3,17,02,30,04,05,10,09,06,31,12,,,1.2,0.8,0.9*35 Example 2 (Combined GPS and GLONASS): $GNGSA,M,3,17,02,30,04,05,10,09,06,31,12,,,1.2,0.8,0.9*2B $GNGSA,M,3,87,70,,,,,,,,,,,1.2,0.8,0.9*2A ---------------------------------------------------------- SN Field Description Symbol Example ---------------------------------------------------------- 1 $GPGSA Log header. For information about the log headers, see ASCII, Abbreviated ASCII or Binary. N/A $GPGSA 2 mode MA Mode: 1 = Fix not available; 2 = 2D; 3 = 3D x 3 3 mode 123 Latitude (DDmm.mm) llll.ll 5106.9847 4-15 prn PRN numbers of satellites used in solution (null for unused fields), total of 12 fields GPS = 1 to 32 SBAS = 33 to 64 (add 87 for PRN number) GLO = 65 to 96 xx,xx,..... 18,03,13,25,16,24,12,20,,,, The detail info, please see https://docs.novatel.com/OEM7/Content/Logs/GPGSA.htm?tocpath=Commands%20%2526%20Logs%7CLogs%7CGNSS%20Logs%7C_____63 ''' GPGSA_dict = { "msg_id": 0, "mode1": 1, "mode2": 2, "ch1": 3, "ch2": 4, "ch3": 5, "ch4": 6, "ch5": 7, "ch6": 8, "ch7": 9, "ch8": 10, "ch9": 11, "ch10": 12, "ch11": 13, "ch12": 14, } #Reference information of the GPGGA format. ''' Example 1 (GPS only): $GPGSA,M,3,17,02,30,04,05,10,09,06,31,12,,,1.2,0.8,0.9*35 Example 2 (Combined GPS and GLONASS): $GNGSA,M,3,17,02,30,04,05,10,09,06,31,12,,,1.2,0.8,0.9*2B $GNGSA,M,3,87,70,,,,,,,,,,,1.2,0.8,0.9*2A --------------------------------------------------------- SN Field Description Symbol Example --------------------------------------------------------- 1 $GPGGA Log header. For information about the log headers, see ASCII, Abbreviated ASCII or Binary. N/A $GPGGA 2 utc UTC time status of position (hours/minutes/seconds/ decimal seconds) hhmmss.ss 202134.00 3 lat Latitude (DDmm.mm) llll.ll 5106.9847 4 lat dir Latitude direction (N = North, S = South) a N 5 lon Latitude direction (N = North, S = South) yyyyy.yy 11402.2986 6 lon dir Longitude direction (E = East, W = West) a W 7 quality refer to Table: GPS Quality Indicators x 1 8 # sats Number of satellites in use. May be different to the number in view xx 10 The detail info, please see https://docs.novatel.com/OEM7/Content/Logs/GPGGA.htm?tocpath=Commands%20%2526%20Logs%7CLogs%7CGNSS%20Logs%7C_____59 ''' GPGGA_dict = { "msg_id": 0, "utc": 1, "latitude": 2, "NorS": 3, "longitude": 4, "EorW": 5, "pos_indi": 6, "total_Satellite": 7, } uart_port = "/dev/ttyS0" def IsValidGpsinfo(gps): data = gps.readline() #Convert the data to string. msg_str = str(data, encoding="utf-8") #Split string with ",". #GPGSA,A,1,,,,,,,,,,,,,99.99,99.99,99.99*30 msg_list = msg_str.split(",") #Parse the GPGSA message. if (msg_list[GPGSA_dict['msg_id']] == "$GPGSA"): print() #Check if the positioning is valid. if msg_list[GPGSA_dict['mode2']] == "1": print("!!!!!!Positioning is invalid!!!!!!") else: print("*****The positioning type is {}D *****".format(msg_list[GPGSA_dict['mode2']])) print("The Satellite ID of channel {} : {}") #Parse the channel information of the GPGSA message. for id in range(0, 12): key_name = list(GPGSA_dict.keys())[id + 3] value_id = GPGSA_dict[key_name] if not (msg_list[value_id] == ''): print(" {} : {}".format(key_name, msg_list[value_id])) #Parse the GPGGA message. if msg_list[GPGGA_dict['msg_id']] == "$GPGGA": print() print("*****The GGA info is as follows: *****") for key, value in GPGGA_dict.items(): #Parse the utc information. if key == "utc": utc_str = msg_list[GPGGA_dict[key]] if not utc_str == '': h = int(utc_str[0:2]) m = int(utc_str[2:4]) s = float(utc_str[4:]) print(" utc time: {}:{}:{}".format(h,m,s)) print(" {} time: {} (format: hhmmss.sss)".format(key, msg_list[GPGGA_dict[key]])) #Parse the latitude information. elif key == "latitude": lat_str = msg_list[GPGGA_dict[key]] if not lat_str == '': Len = len(lat_str.split(".")[0]) d = int(lat_str[0:Len-2]) m = float(lat_str[Len-2:]) print(" latitude: {} degree {} minute".format(d, m)) print(" {}: {} (format: dddmm.mmmmm)".format(key, msg_list[GPGGA_dict[key]])) #Parse the longitude information. elif key == "longitude": lon_str = msg_list[GPGGA_dict[key]] if not lon_str == '': Len = len(lon_str.split(".")[0]) d = int(lon_str[0:Len-2]) m = float(lon_str[Len-2:]) print(" longitude: {} degree {} minute".format(d, m)) print(" {}: {} (format: dddmm.mmmmm)".format(key, msg_list[GPGGA_dict[key]])) else: print(" {}: {}".format(key, msg_list[GPGGA_dict[key]])) def main(): gps = serial.Serial(uart_port, baudrate=9600, timeout=0.5) while True: IsValidGpsinfo(gps) time.sleep(1) gps.close() if __name__ == "__main__": sys.exit(main())