2025年6月7日 星期六

實作物聯網網站用Django+AJAX+JavaScript整合MQTT

 

1.安裝套件

pip install django

pip install paho-mqtt

2.建立mqtttest專案

django-admin startproject mqtttest

3.進入專案

cd mqtttest

4.建立app

python manage.py startapp mqttapp

5.修改mqtttest/mqtttest/settings.py

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"""
Django settings for mqtttest project.

Generated by 'django-admin startproject' using Django 4.2.9.

For more information on this file, see
https://docs.djangoproject.com/en/4.2/topics/settings/

For the full list of settings and their values, see
https://docs.djangoproject.com/en/4.2/ref/settings/
"""

from pathlib import Path

# Build paths inside the project like this: BASE_DIR / 'subdir'.
BASE_DIR = Path(__file__).resolve().parent.parent


# Quick-start development settings - unsuitable for production
# See https://docs.djangoproject.com/en/4.2/howto/deployment/checklist/

# SECURITY WARNING: keep the secret key used in production secret!
SECRET_KEY = 'django-insecure-q2ia=(7x3d5_mxao#-sl)+)crp9j%e*732fg4jhid-f&sln5k('

# SECURITY WARNING: don't run with debug turned on in production!
DEBUG = True

ALLOWED_HOSTS = []


# Application definition

INSTALLED_APPS = [
    'django.contrib.admin',
    'django.contrib.auth',
    'django.contrib.contenttypes',
    'django.contrib.sessions',
    'django.contrib.messages',
    'django.contrib.staticfiles',
    'mqttapp',
]

MIDDLEWARE = [
    'django.middleware.security.SecurityMiddleware',
    'django.contrib.sessions.middleware.SessionMiddleware',
    'django.middleware.common.CommonMiddleware',
    'django.middleware.csrf.CsrfViewMiddleware',
    'django.contrib.auth.middleware.AuthenticationMiddleware',
    'django.contrib.messages.middleware.MessageMiddleware',
    'django.middleware.clickjacking.XFrameOptionsMiddleware',
]

ROOT_URLCONF = 'mqtttest.urls'

TEMPLATES = [
    {
        'BACKEND': 'django.template.backends.django.DjangoTemplates',
        'DIRS': [BASE_DIR / 'templates'],
        'APP_DIRS': True,
        'OPTIONS': {
            'context_processors': [
                'django.template.context_processors.debug',
                'django.template.context_processors.request',
                'django.contrib.auth.context_processors.auth',
                'django.contrib.messages.context_processors.messages',
            ],
        },
    },
]

WSGI_APPLICATION = 'mqtttest.wsgi.application'


# Database
# https://docs.djangoproject.com/en/4.2/ref/settings/#databases

DATABASES = {
    'default': {
        'ENGINE': 'django.db.backends.sqlite3',
        'NAME': BASE_DIR / 'db.sqlite3',
    }
}


# Password validation
# https://docs.djangoproject.com/en/4.2/ref/settings/#auth-password-validators

AUTH_PASSWORD_VALIDATORS = [
    {
        'NAME': 'django.contrib.auth.password_validation.UserAttributeSimilarityValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.MinimumLengthValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.CommonPasswordValidator',
    },
    {
        'NAME': 'django.contrib.auth.password_validation.NumericPasswordValidator',
    },
]


# Internationalization
# https://docs.djangoproject.com/en/4.2/topics/i18n/

LANGUAGE_CODE = 'en-us'

TIME_ZONE = 'UTC'

USE_I18N = True

USE_TZ = True


# Static files (CSS, JavaScript, Images)
# https://docs.djangoproject.com/en/4.2/howto/static-files/

STATIC_URL = 'static/'

# Default primary key field type
# https://docs.djangoproject.com/en/4.2/ref/settings/#default-auto-field

DEFAULT_AUTO_FIELD = 'django.db.models.BigAutoField'

MQTT_SERVER = 'broker.MQTTGO.io'
MQTT_PORT = 1883
MQTT_KEEPALIVE = 60
MQTT_USER = ''
MQTT_PASSWORD = ''

6.修改mqtttest/mqtttest/urls.py

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"""
URL configuration for mqtttest project.

The `urlpatterns` list routes URLs to views. For more information please see:
    https://docs.djangoproject.com/en/4.2/topics/http/urls/
Examples:
Function views
    1. Add an import:  from my_app import views
    2. Add a URL to urlpatterns:  path('', views.home, name='home')
Class-based views
    1. Add an import:  from other_app.views import Home
    2. Add a URL to urlpatterns:  path('', Home.as_view(), name='home')
Including another URLconf
    1. Import the include() function: from django.urls import include, path
    2. Add a URL to urlpatterns:  path('blog/', include('blog.urls'))
"""
from django.contrib import admin
from django.urls import path
from mqttapp.views import home, publish_message, mqtt_messages_json

urlpatterns = [
    path('admin/', admin.site.urls),
    path('', home),
    path('publish/', publish_message, name='publish'),
    path('api/messages/', mqtt_messages_json, name='mqtt_messages_json'),
]

7.mqtttest/mqttapp/models.py

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from django.db import models

# Create your models here.

class MQTTMessage(models.Model):
    received_at = models.DateTimeField(auto_now_add=True)  # 自動紀錄訊息接收時間
    topic = models.CharField(max_length=255)
    payload = models.TextField()

    def __str__(self):
        return f"{self.received_at} - {self.topic}"

8.mqtttest/mqttapp/admin.py

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from django.contrib import admin
from .models import MQTTMessage

@admin.register(MQTTMessage)
class MQTTMessageAdmin(admin.ModelAdmin):
    list_display = ('received_at', 'topic', 'payload')  # 可自訂顯示欄位
    list_filter = ('topic',)
    search_fields = ('topic', 'payload')
    ordering = ('-received_at',)

9.mqtttest/mqttapp/views.py

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from django.shortcuts import render

# Create your views here.
import json
from django.http import JsonResponse
from mqttapp.models import MQTTMessage
from django.views.decorators.csrf import csrf_exempt
import paho.mqtt.client as mqtt

def home(request):
	return render(request, 'index.html')

@csrf_exempt
def publish_message(request):
    if request.method == 'POST':
        try:
            data = json.loads(request.body)
            topic = data.get('topic', 'django/mqtt')
            msg = data.get('msg', 'test')

            # 即時建立連線並發送
            client = mqtt.Client()
            client.connect('broker.MQTTGO.io', 1883, 60)
            rc, mid = client.publish(topic, msg)
            client.disconnect()

            return JsonResponse({'code': rc})
        except Exception as e:
            return JsonResponse({'error': str(e)}, status=400)
    return JsonResponse({'error': 'Only POST allowed'}, status=405)

def mqtt_messages_json(request):
    messages = MQTTMessage.objects.order_by('-received_at')[:20]
    data = [
        {
            'topic': m.topic,
            'payload': m.payload,
            'received_at': m.received_at.strftime('%Y-%m-%d %H:%M:%S')
        }
        for m in messages
    ]
    return JsonResponse(data, safe=False)

10.在mqtttest下建立templates資料夾,並新增mqtttest/templates/index.html

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<!DOCTYPE html>
<html>
	<head>
		<title>MQTT 測試</title>
		<script>
			function loadMessages() {
				fetch('/api/messages/')
					.then(response => response.json())
					.then(data => {
						const tbody = document.getElementById('messages');
						tbody.innerHTML = '';
						data.forEach(item => {
							const row = `<tr>
								<td>${item.received_at}</td>
								<td>${item.topic}</td>
								<td>${item.payload}</td>
							</tr>`;
							tbody.innerHTML += row;
						});
					});
				}
			function publishMessage() {
				const topic = document.getElementById('topic').value;
				const msg = document.getElementById('msg').value;

				fetch('/publish/', {
					method: 'POST',
					headers: { 'Content-Type': 'application/json' },
					body: JSON.stringify({ topic, msg })
				})
				.then(response => response.json())
				.then(data => {
					alert('已送出 MQTT 訊息!');
				})
				.catch(error => {
					alert('錯誤:' + error);
				});
			}
			setInterval(loadMessages, 3000);
			window.onload = loadMessages;
		</script>
	</head>
	<body>
		<h1>MQTT 測試</h1>
		<h2><a href="https://broker.mqttgo.io/">使用MQTT GO伺服器</a></h2>
		<h2>發送 MQTT 訊息</h2>
		<label>Topic: <input id="topic" value="django/mqtt"></label><br>
		<label>訊息: <input id="msg" value="Hello MQTT!"></label><br>
		<button onclick="publishMessage()">送出</button>
		<h2>最新接收訊息</h2>
		<table border="1">
			<thead>
				<tr><th>時間</th><th>主題</th><th>訊息</th></tr>
			</thead>
			<tbody id="messages"></tbody>
		</table>
	</body>
</html>

12.在mqtttest根目錄下建立mqtt_listener.py

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import os
import django
import paho.mqtt.client as mqtt

# 初始化 Django 環境
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "mqtttest.settings")
django.setup()

from mqttapp.models import MQTTMessage
from django.conf import settings

def on_connect(client, userdata, flags, rc):
    if rc == 0:
        print("Connected to MQTT broker.")
        client.subscribe("django/mqtt")
    else:
        print("Connection failed with code", rc)

def on_message(client, userdata, msg):
    payload = msg.payload.decode('utf-8')
    print(f"Received message on topic: {msg.topic}, payload: {payload}")
    MQTTMessage.objects.create(topic=msg.topic, payload=payload)

client = mqtt.Client()
client.on_connect = on_connect
client.on_message = on_message
client.username_pw_set(settings.MQTT_USER, settings.MQTT_PASSWORD)
client.connect(settings.MQTT_SERVER, settings.MQTT_PORT, settings.MQTT_KEEPALIVE)

client.loop_forever()

13.回到命令列,做資料庫同步,並建立超級使用者
python manage.py makemigrations
python manage.py migrate

14.執行網站
python manage.py runserver



15.再打啟另一個命令列
python mqtt_listener.py



16.啟動MQTT GO,連線並訂閱django/mqtt



17.打開瀏覽器進行測試,如最上圖

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