Get NMEA and parse to LatLong using Waveshare GNSS, GPRS hat - https://www.waveshare.com/wiki/GSM/GPRS/GNSS_HAT

GPRS.waveshare.serial.py

##!/usr/bin/python
import serial
import time
import pynmea2
import json

# Change to location of device
serialPort = "/dev/ttyS0"

class Commands(object):
    GNSS_POWER_ON = "AT+CGNSPWR=1\r\n"
    GNSS_GET_NMEA = "AT+CGNSINF\r\n"
    GNSS_REC_UART = "AT+CGNSTST=1\r\n"
commands = Commands()


def get_latlong():
    output = ""

    ser = serial.Serial(serialPort,115200)

    ser.flushInput()
    ser.flushOutput()

    ser.write(commands.GNSS_POWER_ON.encode())
    ser.write(commands.GNSS_REC_UART.encode())
    ser.write(commands.GNSS_GET_NMEA.encode())

    print("Waiting for signal...")

    try:
        while True:

            # Keep sending text stream to output
            while ser.inWaiting() > 0:
                try:
                    output = ser.read(ser.inWaiting()).decode()
                except:
                     ## If error, re-run
                     self.get_latlong()
                     return;

            # Split the output lines from the device into an array
            if output != "":
                lines = output.split('\n')

                # Iterate over output lines
                for i in lines:

                    # Get the bit we need
                    if i.startswith('$GNRMC'):
                        try:

                            # Parse $GNRMC format
                            msg = pynmea2.parse(i)
                            if(msg.latitude!=0.0):

                                ## Log to console
                                print(f'LAT: {msg.latitude}')
                                print(f'LON: {msg.longitude}')
                                print(f'TIME: {time.time()}')

                                ## JSON data
                                data = {
                                    "latitude" : msg.latitude,
                                    "longitude" : msg.longitude,
                                    "time" : time.time()
                                }

                                ## Close connection to device
                                ser.close()

                                ## Return
                                return json.dumps(data)
                            else:
                                print("Couldn't parse $GNRMC line from device. Retrying...");

                        except pynmea2.ParseError:
                            ## If error, re-run
                            self.get_latlong()
                            return;

            # Wait for half a second before looping again
            time.sleep(0.5)

    except KeyboardInterrupt:
        if ser != None:
            ser.close()