ESP32/ESP8266のMicroPythonでMQTTを使ってみた: xshige's beta notes

2020年3月 3日 (火)

ESP32/ESP8266のMicroPythonでMQTTを使ってみた

2020/3/3

ESP32/ESP8266 MicroPython MQTT test

概要

ESP32/ESP8266のMicroPythonで以下のリンクを参照してMQTTを使ってみた。ここでは、linux環境でのインストール方法について説明する。

MicroPython – Getting Started with MQTT on ESP32/ESP8266

準備

ツールをインストール前に環境整備として以下を設定する：
(1)書き込みツール(esptool)のインストール
以下のURLの参照のこと；
esptool.py

(この記事のなかでは使用しない)

(2)ampyのインストール
AMPY_PORTは、自分の環境に合わせる。


  pip install adafruit-ampy
  export AMPY_PORT=/dev/ttyUSB0
  export AMPY_BAUD=115200

(3)picocomのインストール


  sudo apt-get install picocom

以上のうち、exportしているものは、.bashrcに登録することを勧める。

ESP#1側のスクリプト

MQTT01_test.py
以下の部分は自分の環境に合わせる：
ssid = 'your_ssid'
password = 'your_passws'


  # boot.py
  ssid = 'your_ssid'
  password = 'your_passws'
  mqtt_server = '5.196.95.208'

  # Complete project details at https://RandomNerdTutorials.com

  import time
  from umqttsimple import MQTTClient
  import ubinascii
  import machine
  import micropython
  import network
  import esp
  esp.osdebug(None)
  import gc
  gc.collect()

  client_id = ubinascii.hexlify(machine.unique_id())
  # ESP#1
  topic_sub = b'notification'
  topic_pub = b'hello'
  # ESP#2
  #topic_sub = b'hello'
  #topic_pub = b'notification'

  last_message = 0
  message_interval = 5
  counter = 0

  station = network.WLAN(network.STA_IF)

  station.active(True)
  station.connect(ssid, password)

  while station.isconnected() == False:
    pass

  print('Connection successful')
  print(station.ifconfig())
  #===========================================
  # ESP#1
  # main.py

  # Complete project details at https://RandomNerdTutorials.com

  def sub_cb(topic, msg):
    print((topic, msg))
    if topic == b'notification' and msg == b'received':
      print('ESP received hello message')

  def connect_and_subscribe():
    global client_id, mqtt_server, topic_sub
    client = MQTTClient(client_id, mqtt_server)
    client.set_callback(sub_cb)
    client.connect()
    client.subscribe(topic_sub)
    print('Connected to %s MQTT broker, subscribed to %s topic' % (mqtt_server, topic_sub))
    return client

  def restart_and_reconnect():
    print('Failed to connect to MQTT broker. Reconnecting...')
    time.sleep(10)
    machine.reset()

  try:
    client = connect_and_subscribe()
  except OSError as e:
    restart_and_reconnect()

  while True:
    try:
      client.check_msg()
      if (time.time() - last_message) > message_interval:
        msg = b'Hello #%d' % counter
        client.publish(topic_pub, msg)
        last_message = time.time()
        counter += 1
    except OSError as e:
      restart_and_reconnect()

ESP#2側のスクリプト

MQTT02_test.py
以下の部分は、自分の環境に合わせる：
ssid = 'your_ssid'
password = 'your_passwd'

# boot.py
  ssid = 'your_ssid'
  password = 'your_passwd'
  mqtt_server = '5.196.95.208'

  # Complete project details at https://RandomNerdTutorials.com

  import time
  from umqttsimple import MQTTClient
  import ubinascii
  import machine
  import micropython
  import network
  import esp
  esp.osdebug(None)
  import gc
  gc.collect()

  client_id = ubinascii.hexlify(machine.unique_id())
  # ESP#1
  #topic_sub = b'notification'
  #topic_pub = b'hello'
  # ESP#2
  topic_sub = b'hello'
  topic_pub = b'notification'

  last_message = 0
  message_interval = 5
  counter = 0

  station = network.WLAN(network.STA_IF)

  station.active(True)
  station.connect(ssid, password)

  while station.isconnected() == False:
    pass

  print('Connection successful')
  print(station.ifconfig())
  #===========================================
  # ESP#2
  # main.py

  # Complete project details at https://RandomNerdTutorials.com

  def sub_cb(topic, msg):
    print((topic, msg))

  def connect_and_subscribe():
    global client_id, mqtt_server, topic_sub
    client = MQTTClient(client_id, mqtt_server)
    client.set_callback(sub_cb)
    client.connect()
    client.subscribe(topic_sub)
    print('Connected to %s MQTT broker, subscribed to %s topic' % (mqtt_server, topic_sub))
    return client

  def restart_and_reconnect():
    print('Failed to connect to MQTT broker. Reconnecting...')
    time.sleep(10)
    machine.reset()

  try:
    client = connect_and_subscribe()
  except OSError as e:
    restart_and_reconnect()

  while True:
    try:
      new_message = client.check_msg()
      if new_message != 'None':
        client.publish(topic_pub, b'received')
      time.sleep(1)
    except OSError as e:
      restart_and_reconnect()

実行/出力ログ

ESP#1側：

>>> 
  >>> import MQTT01_test
  Connection successful
  ('192.168.0.4', '255.255.255.0', '192.168.0.1', '192.168.0.1')
  Connected to 5.196.95.208 MQTT broker, subscribed to b'notification' topic
  (b'notification', b'received')
  ESP received hello message
  (b'notification', b'received')
  ESP received hello message
  (b'notification', b'received')
  ESP received hello message
  (b'notification', b'received')
  ESP received hello message
  (b'notification', b'received')
  ESP received hello message
  ...
  ...

ESP#2側：


  >>> import MQTT02_test
  Connection successful
  ('192.168.0.31', '255.255.255.0', '192.168.0.1', '192.168.0.1')
  Connected to 5.196.95.208 MQTT broker, subscribed to b'hello' topic
  (b'hello', b'Hello #1')
  (b'hello', b'Hello #2')
  (b'hello', b'Hello #3')
  (b'hello', b'Hello #4')
  (b'hello', b'Hello #5')
  (b'hello', b'Hello #6')
  mqtt reconnect
  (b'hello', b'Hello #7')
  mqtt reconnect ok
  (b'hello', b'Hello #8')
  (b'hello', b'Hello #9')
  (b'hello', b'Hello #10')
  ...
  ...

Brokerサーバーについて

２つのESP間を仲介するBrokerサーバーについては公開されているtest.mosquitto.orgを使用した。そのIPアドレスはpingで取得した。(pingの結果より、5.196.95.208となる)


  $ ping test.mosquitto.org
  PING test.mosquitto.org (5.196.95.208) 56(84) bytes of data.
  64 bytes from test.mosquitto.org (5.196.95.208): icmp_seq=1 ttl=51 time=257 ms
  ...