main.py

import usocket as socket
import ustruct as struct
import utime
import machine

from machine import RTC
from machine import Pin

# (date(2000, 1, 1) - date(1900, 1, 1)).days * 24*60*60
NTP_DELTA = 3155673600
host = "pool.ntp.org"
lightcnt = 8
seconds_per_day = 86400
periods_per_day = 2 ** lightcnt
seconds_per_period = seconds_per_day // periods_per_day

global display_state
display_state = 0

global max_display_state
max_display_state = periods_per_day - 1

global display_formatter
display_formatter = '{0:0' + str(lightcnt) + 'b}'

global pins
pins = {}
for i in range(16):
    pins[i] = Pin('GP' + str(i), mode=Pin.OUT)

global wakeup
wakeup = False

def gettime():
    NTP_QUERY = bytearray(48)
    NTP_QUERY[0] = 0x1b
    addr = socket.getaddrinfo(host, 123)[0][-1]
    s = socket.socket(socket.AF_INET, socket.SOCK_DGRAM)
    s.settimeout(1)
    res = s.sendto(NTP_QUERY, addr)
    msg = s.recv(48)
    s.close()
    val = struct.unpack("!I", msg[40:44])[0]
    return val - NTP_DELTA

def tick():
    global display_state

    if display_state == max_display_state:
        display_state -= max_display_state
    else:
        display_state += 1

    for idx, val in enumerate(list(display_formatter.format(display_state))):
        pins[idx].value(int(val))

def alarm_handler (rtc_o):
    global wakeup
    wakeup = True

t = gettime()
tm = utime.localtime(t)
rtc = RTC(datetime=tm)
rtc.alarm(time=1000, repeat=True)
rtc_i = rtc.irq(trigger=RTC.ALARM0, handler=alarm_handler, wake=machine.SLEEP | machine.IDLE)

while True:
    machine.idle()

    if wakeup == True:
        tick()
        wakeup = False