ESP32/ESP8266のMicroPythonでRTCを現在時刻に合わせる方法

2020/3/6

ESP32/ESP8266 MicroPython Clock

ESP32/ESP8266 MicroPython Clock

概要

ESP32/ESP8266のMicroPythonでRTCを現在時刻に合わせる方法を記する。ここでは、デモとして簡単な時計表示を行なう。

micropythonスクリプト

ESP32_8266_clock.py
以下は自分の環境に合わせる：
ssid = 'your_ssid'
password = 'your_passwd'

  # NIC setup
  import network, socket

  WIFI_SSID = "your_ssid"
  WIFI_PASSWD = "your_passwd"

  def wlan_connect(ssid='SSID', password='PASSWD'):
      import network
      wlan = network.WLAN(network.STA_IF)
      if not wlan.active() or not wlan.isconnected():
          wlan.active(True)
          print('connecting to:', ssid)
          wlan.connect(ssid, password)
          while not wlan.isconnected():
              pass


  wlan_connect(ssid=WIFI_SSID, password=WIFI_PASSWD)

  #==========================================
  # ESP32_8266_clock.py

  from machine import Pin, RTC
  import network, urequests, utime
  import ujson
  rtc = RTC()

  url_jst = "http://worldtimeapi.org/api/timezone/Asia/Tokyo" # see http://worldtimeapi.org/timezones

  retry_delay = 5000 # interval time of retry after a failed Web query
  response = urequests.get(url_jst)

  # parse JSON
  parsed = response.json()
  #parsed=ujson.loads(res) # in case string
  datetime_str = str(parsed["datetime"])
  year = int(datetime_str[0:4])
  month = int(datetime_str[5:7])
  day = int(datetime_str[8:10])
  hour = int(datetime_str[11:13])
  minute = int(datetime_str[14:16])
  second = int(datetime_str[17:19])
  subsecond = int(round(int(datetime_str[20:26]) / 10000))

  # update internal RTC
  rtc.datetime((year, month, day, 0, hour, minute, second, subsecond))

  # setup day of the week
  daysOfTheWeek = "Mon", "Tue", "Wed", "Thu", "Fri", "Sat", "Sun"
  tm = utime.localtime(utime.mktime(utime.localtime()))

  while True:
    # generate formated date/time strings from internal RTC
    date_str = "Date: {0:4d}/{1:02d}/{2:02d}".format(*rtc.datetime())+' ('+daysOfTheWeek[tm[6]]+')'
    time_str = "Time: {4:02d}:{5:02d}:{6:02d}".format(*rtc.datetime())
    print(date_str)
    print(time_str)
    print('-----------')
    utime.sleep(1)

  #=============================================
  

ここでは、World Time APIのサーバーから現在時刻を取得して時刻合わせを行なう。

他の方法

ネットワークが接続済みが前提で以下のスクリプトでも時刻合わせができる。(NTPサーバーを利用している)

#===========================================
  from machine import RTC
  import utime
  import ntptime
  rtc = RTC()
  ntptime.settime() # setup time by remote NTP server

  def get_jst():
     tm = utime.localtime(utime.time()) # UTC now
     jst = str(tm[0])+'/'+str(tm[1])+'/'+str(tm[2])+' '+str((tm[3]+9)%24)+':'+str(tm[4])+':'+str(tm[5])
     return jst

  #===========================================
  

実行画面

  picocom /dev/ttyUSB0 -b115200

  import ESP32_8266_clock

  Date: 2020/03/06 (Fri)
  Time: 12:29:20
  -----------
  Date: 2020/03/06 (Fri)
  Time: 12:29:21
  -----------
  Date: 2020/03/06 (Fri)
  Time: 12:29:22
  -----------
  Date: 2020/03/06 (Fri)
  Time: 12:29:23
  -----------
  Date: 2020/03/06 (Fri)
  Time: 12:29:24
  -----------
  Date: 2020/03/06 (Fri)
  Time: 12:29:25
  -----------
  Date: 2020/03/06 (Fri)
  Time: 12:29:26
  -----------
  ...
  

参考情報

World Time API

Very Simple MicroPython ESP8266/ESP-12 Web Clock

以上