# SPDX-FileCopyrightText: 2021 ladyada for Adafruit Industries # SPDX-License-Identifier: MIT # Simple script using GPS timestamps as RTC time source # The GPS timestamps are available without a fix and keep the track of # time while there is powersource (ie coin cell battery) import time import board import busio import rtc import adafruit_gps uart = busio.UART(board.TX, board.RX, baudrate=9600, timeout=10) # i2c = busio.I2C(board.SCL, board.SDA) gps = adafruit_gps.GPS(uart, debug=False) # gps = adafruit_gps.GPS_GtopI2C(i2c, debug=False) # Use I2C interface gps.send_command(b"PMTK314,0,1,0,1,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0") gps.send_command(b"PMTK220,1000") print("Set GPS as time source") rtc.set_time_source(gps) the_rtc = rtc.RTC() def _format_datetime(datetime): date_part = f"{datetime.tm_mon:02}/{datetime.tm_mday:02}/{datetime.tm_year}" time_part = f"{datetime.tm_hour:02}:{datetime.tm_min:02}:{datetime.tm_sec:02}" return f"{date_part} {time_part}" last_print = time.monotonic() while True: gps.update() # Every second print out current time from GPS, RTC and time.localtime() current = time.monotonic() if current - last_print >= 1.0: last_print = current if not gps.timestamp_utc: print("No time data from GPS yet") continue # Time & date from GPS informations print(f"Fix timestamp: {_format_datetime(gps.timestamp_utc)}") # Time & date from internal RTC print(f"RTC timestamp: {_format_datetime(the_rtc.datetime)}") # Time & date from time.localtime() function local_time = time.localtime() print(f"Local time: {_format_datetime(local_time)}")