GPS/GNSS

Configure, generate, read, poll, send and parse GPS/GNSS messages.

Read GNSS1 and GNSS2 messages

This code reads the incoming messages from Gps1 and Gps2.
In this example, Gps1 is not sending any information, while Gps2 is sending a binary UBX message.
You can find more information about the Gps class here: GPS – Global Positioning System.

>>> import sbc
>>> gps1 = sbc.Gps( 1, 115200 )
>>> gps2 = sbc.Gps( 2, 115200 )
>>> print(gps1.read())
None
>>> print(gps2.read())
b'\x02\x00\xc4\x00\x00\x00\x91\x00\x00\x00\x89p\x00\x00\x00\x00\x00\x00/\x01\x00\x00ho'

Poll UBX-PVT message

This example requests Gps1 to send one UBX-PVT message.
You can find more information about the ubx.Parser class here: UBX Parser.

>>> import sbc
>>> import time
>>> gps2 = sbc.Gps(2, 115200)
>>> ubx_parser = sbc.ubx.Parser()
>>> msg = sbc.ubx.request( gps2, ubx_parser, "NavPvt" )
>>> print( msg )
NavPvt {'lat': 416087000, 'vAcc': 486, 'itow': 374515700, 'height': 252417, 'year': 2021, 'sAcc': 90, 'flags': 67, 'headVeh': 0, 'hAcc': 373, 'reserved3': 1044519020, 'reserved2': 0, 'magDec': 0, 'magAcc': 0, 'hour': 8, 'day': 25, 'valid': 55, 'min': 1, 'headingAcc': 13376102, 'name': 'NavPvt', 'tAcc': 21, 'numSV': 29, 'velN': -43, 'flags3': 0, 'hMSL': 202610, 'sec': 37, 'gSpeed': 44, 'month': 3, 'fixType': 3, 'nano': 699554746, 'flags2': 234, 'heading': 13758188, 'velD': 28, 'velE': 11, 'pDop': 109, 'lon': 6117282}

Set default configuration

This example sends the UBX hexadecimal string to bring the GPS/GNSS receiver to its default configuration.
You can discover this strings in u-center and practically do anything you can in u-center with the SBC.
You can find more information about the ubx.Parser class here: UBX Parser.

>>> import sbc
>>> payload = bytes( [ 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xFF, 0xFF, 0x00, 0x00, 0x03 ] )
>>> gps1 = sbc.Gps(1, uart_baudrate = 38400)
>>> ubx_parser = sbc.ubx.Parser()
>>> print(sbc.ubx.config( gps1, ubx_parser, 0x06, 0x09, payload ))
True

Parse UBX messages

This example parses a UBX message and prints the parsed message with all its fields.
You can find more information about the ubx.Parser class here: UBX Parser.

>>> import sbc
>>> ubx_parser = sbc.ubx.Parser(raw_payload=False)
>>> ubx_msg = bytes([0xB5, 0x62, 0x01, 0x07, 0x5C, 0x00, 0xB8, 0x39, 0x92, 0x17, 0xE5, 0x07, 0x03, 0x12, 0x0D, 0x32, 0x29, 0x37, 0x19, 0x00, 0x00, 0x00, 0xB9, 0xE9, 0xFC, 0xFF, 0x03, 0x03, 0xEA, 0x19, 0x1E, 0x59, 0x5D, 0x00, 0x46, 0xFB, 0xCC, 0x18, 0x8F, 0xDE, 0x03, 0x00, 0xFF, 0x1B, 0x03, 0x00, 0xD8, 0x05, 0x00, 0x00, 0xD5, 0x06, 0x00, 0x00, 0xEF, 0xFF, 0xFF, 0xFF, 0x00, 0x00, 0x00, 0x00, 0x07, 0x00, 0x00, 0x00, 0x11, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xA5, 0x00, 0x00, 0x00, 0x80, 0xA8, 0x12, 0x01, 0x5F, 0x00, 0x00, 0x00, 0x6C, 0x18, 0x42, 0x3E, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0xE2, 0x62])
>>> msg = ubx_parser.parse(ubx_msg)
>>> print(msg)
[NavPvt {'lat': 416086854, 'vAcc': 1749, 'itow': 395459000, 'height': 253583, 'year': 2021, 'sAcc': 165, 'flags': 3, 'headVeh': 0, 'hAcc': 1496, 'reserved3': 1044519020, 'reserved2': 0, 'magDec': 0, 'magAcc': 0, 'hour': 13, 'day': 18, 'valid': 55, 'min': 50, 'headingAcc': 18000000, 'name': 'NavPvt', 'tAcc': 25, 'numSV': 25, 'velN': -17, 'flags3': 0, 'hMSL': 203775, 'sec': 41, 'gSpeed': 17, 'month': 3, 'fixType': 3, 'nano': -202311, 'flags2': 234, 'heading': 0, 'velD': 7, 'velE': 0, 'pDop': 95, 'lon': 6117662}]

Parse NMEA messages

This example parses a NMEA message and prints the parsed message with all its fields.
You can find more information about the NMEA_parser class here: NMEA Parser.

>>> import sbc
>>> nmea = sbc.NMEA_parser(split_payload = True)
>>> buf = b'$GPGGA,172814.0,3723.46587704,N,12202.26957864,W,2,6,1.2,18.893,M,-25.669,M,2.0,0031*4F'
>>> buf = buf + 'This is not a NMEA message'
>>> buf = buf + b'$GPGST,172814.0,0.006,0.023,0.020,273.6,0.023,0.020,0.031*6A'
>>> msg = nmea.parse(buf)
>>> print(msg)
[['GPGGA', '172814.0', '3723.46587704', 'N', '12202.26957864', 'W', '2', '6', '1.2', '18.893', 'M', '-25.669', 'M', '2.0', '0031'], ['GPGST', '172814.0', '0.006', '0.023', '0.020', '273.6', '0.023', '0.020', '0.031']]

Generate NMEA message

This example builds a NMEA message from a defined payload.
You can find more information about the NMEA_parser class here: NMEA Parser.

>>> import sbc
>>> nmea = sbc.NMEA_parser()
>>> nmea.payload = b'GPGGA,172814.0,3723.46587704,N,12202.26957864,W,2,6,1.2,18.893,M,-25.669,M,2.0,0031'
>>> nmea.payload_len = len(nmea.payload)
>>> print(nmea.chksum_nmea())
b'4F'
>>> msg = b'$' + nmea.payload + b'*' + nmea.chksum_nmea()
>>> print(msg.decode())
$GPGGA,172814.0,3723.46587704,N,12202.26957864,W,2,6,1.2,18.893,M,-25.669,M,2.0,0031*4F