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123 | from machine import Pin
import machine
import network
import ntptime # library for Network Time Protocol
import ssd1306 # OLED display driver
import secrets # your WiFi network name and password
from utime import sleep, sleep_ms, time, localtime, mktime, ticks_ms, ticks_diff
from machine import RTC # built-in Real-Time Clock
# set up the OLED display over SPI
WIDTH = 128
HEIGHT = 64
SCK = machine.Pin(2) # SPI clock pin
SDL = machine.Pin(3) # SPI data pin (MOSI)
spi = machine.SPI(0, baudrate=100000, sck=SCK, mosi=SDL)
CS = machine.Pin(4) # chip select pin
DC = machine.Pin(5) # data/command pin
RES = machine.Pin(6) # reset pin
oled = ssd1306.SSD1306_SPI(WIDTH, HEIGHT, spi, DC, RES, CS)
oled.poweron() # turn on the OLED screen
# set your time zone offset in hours from UTC
time_zone = -6 # US Central time (change for your location)
ntptime.host = 'us.pool.ntp.org' # address of the NTP time server
ntptime.timeout = 10 # wait up to 10 seconds per attempt
def wifi_connect():
wifi = network.WLAN(network.STA_IF) # create WiFi object in station mode
wifi.active(True) # power on the WiFi chip
wifi.config(pm = 0xa11140) # disable WiFi sleep mode for stability
if not wifi.isconnected():
wifi.connect(secrets.SSID, secrets.PASSWORD) # try to connect
print('Connecting..', end='')
max_wait = 10 # try for up to 10 seconds
while max_wait > 0:
if wifi.status() < 0 or wifi.status() >= 3:
break # connected or error — stop waiting
sleep_ms(1000) # wait one second between checks
print('.', end='') # show a dot for each second
max_wait -= 1
print()
if wifi.status() != 3:
print('Could not connect to wifi!')
sleep_ms(100) # small delay to stabilize
return wifi
def is_daylight_saving_time():
# check whether Daylight Saving Time is in effect (US rules)
year, weekday = localtime()[0], localtime()[6]
dst_start = mktime((year, 3, (8 - weekday) % 7 + 8, 2, 0, 0, 0, 0)) # 2nd Sunday in March
dst_end = mktime((year, 11, (1 - weekday) % 7 + 1, 2, 0, 0, 0, 0)) # 1st Sunday in November
return dst_start <= time() < dst_end # True if we are currently in DST
# global variables to store the formatted time and date strings
time_str = ''
date_str = ''
clock_values = []
def set_rtc():
global time_str, date_str, clock_values
time_was_set = False
attempts = 0
max_attempts = 5
while not time_was_set and attempts < max_attempts:
attempts += 1
try:
ntptime.settime() # ask the NTP server for the current UTC time
time_was_set = True
except:
print(f'NTP update attempt # {attempts} of {max_attempts} failed!',
'Retrying in 15 seconds..' if attempts < max_attempts else 'Check connection/config.')
if attempts < max_attempts:
sleep_ms(15000) # wait 15 seconds before trying again
if time_was_set:
sleep_ms(200)
rtc = RTC() # access the internal Real-Time Clock
# add 1 hour extra if Daylight Saving Time is active
tz_offset = (time_zone + 1) * 3600 if is_daylight_saving_time() else time_zone * 3600
local_time = localtime(time() + tz_offset) # convert UTC to local time
# store the local time in the RTC
rtc.datetime((local_time[0], local_time[1], local_time[2],
local_time[6], local_time[3], local_time[4], local_time[5], 0))
sleep_ms(200)
clock_values = rtc.datetime() # read back the time we just set
# format the time as hh:mm am/pm
hour = clock_values[4]
minute = clock_values[5]
am_pm = 'am' if hour < 12 else 'pm'
display_hour = 12 if hour == 0 else hour if hour < 13 else hour - 12
time_str = '%2d:%02d%s' % (display_hour, minute, am_pm)
# format the date as mm/dd/yy
date_str = f'{clock_values[1]}/{clock_values[2]}/{clock_values[0] % 100}'
print(time_str, date_str) # print the current time and date to the console
return True
print('ERROR! Unable to update time from server!')
return False
def update():
# connect to WiFi and sync the internal clock
success = False
wifi = wifi_connect()
sleep_ms(100)
if wifi.isconnected():
success = set_rtc()
sleep_ms(100)
return wifi, success
def update_display():
global time_str, date_str, clock_values
oled.fill(0) # clear the screen
oled.text(time_str + ' ' + date_str, 0, 10, 1) # show time and date on row 10
oled.show() # send the pixel buffer to the OLED screen
while True:
update() # connect to WiFi and sync the clock
update_display() # draw the time and date on the OLED
sleep(60) # wait one minute before updating again
|
In this lab you will combine everything you have learned. Your Pico W will fetch the time from the internet and show it on an OLED screen!
Change 
The SPI pin numbers in this lab (SCK=2, MOSI=3, CS=4, DC=5, RES=6) are different from the weather display lab. Double-check your wiring before running the code.
You built an internet-connected clock that shows the time on a screen! This is a real IoT project you could put anywhere in your home or classroom.