Adafruit_CircuitPython_GPS/examples/gps_time_source.py
2025-05-14 16:16:14 +00:00

55 lines
1.7 KiB
Python

# 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)}")