I2C ublox GPS/GNSS in MicroPython

i2c_gps_test.py

# I could not find any useful examlpes of getting a ublox GNSS working 
# in Micropython, so I wrote this one. My model is the SAM-M8Q and this
# code might also work with other ublox I2C GNSS modules.
#
# In this example I am using micropyGPS.py to parse the NMEA sentences.
# https://github.com/inmcm/micropyGPS
#
# Code is MIT licence
#

import machine, time
from ubinascii import unhexlify
from micropyGPS import MicropyGPS

#my_gps = MicropyGPS()
my_gps = MicropyGPS(location_formatting='dd')

# Create I2C object
i2c = machine.I2C(1, scl=machine.Pin(3), sda=machine.Pin(2), freq=400000)

# Print out any addresses found
devices = i2c.scan()
if devices:
    for d in devices:
        print(hex(d))

gps = 0x42 # i2c address
bufmsb = unhexlify("fd")  # bytes in buffer,
data = unhexlify("ff")  # data stream

def read_reg(dev, reg, length):
    i2c.writeto(dev, reg, False)
    return i2c.readfrom(dev, length)

while True:
    buflen = int.from_bytes(read_reg(gps, bufmsb, 2), "big")
    #print(buflen)
    try:
        if buflen > 0:
            nmeas = read_reg(gps, data, buflen).decode().splitlines()
            for nmea in nmeas:
                for x in nmea:
                    my_gps.update(x)

            print(my_gps.latitude, my_gps.longitude, my_gps.date, my_gps.timestamp)
            break
    except UnicodeError: # if stray \xff chars make it into the buffer, don't crash
        pass
    except IndexError: # if data is not transferred properly, don't crash
        pass
        
    time.sleep(0.1)