picow_ntp_client.py

import network
import socket
import time
import struct

from machine import Pin

NTP_DELTA = 2208988800
host = "pool.ntp.org"

led = Pin("LED", Pin.OUT)

ssid = 'A NETWORK'
password = 'A PASSWORD'

def set_time():
    NTP_QUERY = bytearray(48)
    NTP_QUERY[0] = 0x1B
    addr = socket.getaddrinfo(host, 123)[0][-1]
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    try:
        s.settimeout(1)
        res = s.sendto(NTP_QUERY, addr)
        msg = s.recv(48)
    finally:
        s.close()
    val = struct.unpack("!I", msg[40:44])[0]
    t = val - NTP_DELTA    
    tm = time.gmtime(t)
    machine.RTC().datetime((tm[0], tm[1], tm[2], tm[6] + 1, tm[3], tm[4], tm[5], 0))

wlan = network.WLAN(network.STA_IF)
wlan.active(True)
wlan.connect(ssid, password)

max_wait = 10
while max_wait > 0:
    if wlan.status() < 0 or wlan.status() >= 3:
        break
    max_wait -= 1
    print('waiting for connection...')
    time.sleep(1)

if wlan.status() != 3:
    raise RuntimeError('network connection failed')
else:
    print('connected')
    status = wlan.ifconfig()
    print( 'ip = ' + status[0] )

led.on()
set_time()
print(time.localtime())
led.off()

Hi, using this script provoked the error "machine" is not defined (line 30)
I changed line 6 into: "import machine".
line 11 into led = machine.Pin("LED", machine.Pin.OUT).
Then the script ran OK.

Modified defines for local time and local NTP host
NTP_DELTA = 2208988800 - 3600 # subtract 1 hour = 3600 seconds to get GMT + 1 for Portugal
host = "pt.pool.ntp.org" # using host from Portugal

I'm getting an intermittent failure running the code :

connected
ip = 192.168.3.58
Traceback (most recent call last):
File "", line 52, in
File "", line 24, in set_time
OSError: [Errno 110] ETIMEDOUT

Error message indicates its a time out but not sure what's causing the problem.

@Duncan-Hill

Hi Duncan,
I had that error also. That is why I created a try..except block. See the OSError part of it.

I also created extra logic to call set_time() only at: a) start; b) once in an hour. For the rest every second a REPL print of some time.localtime() data. See the next screenshot at the change of an hour:

Added variable tm_gmtoff, offset of GMT for Portugal:

The original script does call set_time() just once. That is OK for an example as this is.
I have the experience that the RTC's of various microcontollers in time deviate from NTP time.
That is why I decided to call set_time() at intervals to synchronize the built-in RTC.

I am still working on the script to have it fit better to my ideas.

I have published my project on the micropython forum:
https://forum.micropython.org/viewtopic.php?f=21&t=12761&p=69363&hilit=ntp#p69363

Paulus

Modified defines for local time and local NTP host NTP_DELTA = 2208988800 - 3600 # subtract 1 hour = 3600 seconds to get GMT + 1 for Portugal host = "pt.pool.ntp.org" # using host from Portugal

This fixed it for me. Thank you! I had to do "+ 21_600" to get to North America Central Time. Thank you again!

You're welcome