智能家居——阿里雲物聯網套件體驗

背景

本文主要記錄使用阿里雲物聯網套件的方法。
以STM32驅動DHT11讀取溫度、濕度為例，將數據以MQTT方式推送到阿里雲物聯網平台上。
STM32驅動DHT11從串口獲取數據請參考文章《STM32獲取DHT11溫度傳感器數據》

雲平台配置

1. 登陸管理控制台

<1> 登陸阿里雲官網
<2> 產品 -> 物聯網套件 -> 開通服務 or 管理控制台

2. 新建產品、設備

如圖，創建了名為home_automation的產品，以及產品下面兩個設備temperature_sensor和subscribe_test

以MQTT方式發布數據

官方文檔：https://help.aliyun.com/document_detail/30539.html?spm=5176.doc30530.6.574.43QEvm

本示例采用方式二：使用HTTPS認證再連接模式；
按照官網文檔說明，實現HTTPS認證並獲取授權，再通過MQTT通信。

HTTPS認證

HTTPS認證方式參考代碼如下：

#!/usr/bin/python                                                                                                                               
# -*- coding: utf-8 -*-

import json
import time
import hmac
import hashlib
import requests
import traceback


class AliyunIot():
    CONF_FILE = 'config.json'

    def __init__(self, config_file = None):
        if not config_file:
            config_file = self.CONF_FILE
        self.__s = requests.Session()
        self.__config = self.__load_config(config_file)

    def __load_config(self, filename):
        with open(filename) as f:
            return json.load(f, encoding='utf-8')

    def __del__(self):
        self.__s.close()

    def GetSign(self, secret, param):
        black_key_list = ['version', 'sign', 'resources', 'signmethod']
        p = filter(lambda x:x[0] not in black_key_list, param.items())
        c = ''.join([''.join(str(j) for j in i) for i in sorted(p, key=lambda x:x[0])])
        return hmac.new(str(secret), c, hashlib.md5).hexdigest()

    def DeviceAuthentication(self, client_id, resources = 'mqtt'):
        timestamp = int(time.time())

        param = {'productKey': self.__config['productKey'],
                 'deviceName': self.__config['deviceName'],
                 'sign': None,
                 'signmethod': 'hmacmd5',
                 'clientId': client_id,
                 'timestamp': timestamp,
                 'resources': resources}

        param['sign'] = self.GetSign(self.__config['deviceSecret'], param)

        pre = requests.Request('POST', url=self.__config['url'], data=param).prepare()
        res = self.__s.send(pre, cert=self.__config['cert'], timeout=3)
        if res.text:
            try:
                resp = json.loads(res.text)
                if resp['code'] == 200:
                    return resp['data']
            except:
                print res.text
                print 'Http request failed.'
                print traceback.print_exc()
        return None,None

if __name__ == '__main__':
    a = AliyunIot()
    print a.DeviceAuthentication('01')

新建config.json配置如下：

{
    "productKey": "xx",
    "deviceName": "xx",
    "deviceSecret": "xx",
    "url": "https://iot-auth.cn-shanghai.aliyuncs.com/auth/devicename",
    "cert": "aliyun_iot.crt"
}

參數說明：

• productKey：官網產品管理獲取
• deviceName：設備頁面獲取
• deviceSecret：設備頁面 -> 設備證書
• cert：請下載官網文檔中給的，也可選擇不使用證書，但要將python的Requests的verify置為false，方法可網上查閱資料。
  

執行腳本即可得到響應：

pi@raspberrypi:~/IoT/raspberrypi $ ./aliyun_iot.py
{u'iotId': u'xxxxx', u'resources': {u'mqtt': {u'host': u'public.iot-as-mqtt.cn-shanghai.aliyuncs.com', u'port': 1883}}, u'iotToken': u'xxxxxxx'}

MQTT發布消息

從串口讀取數據解析出json

編輯文件iot_serial.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import serial
import json
import time

class Serial:
    def __init__(self, port, baudrate = 9600):
        self.__ser = serial.Serial(port, baudrate, timeout=0.5)

    def __del__(self):
        self.__ser.close()

    def GetData(self):
        self.FlushInput()

        while True:
            time.sleep(0.1)

            text = self.__ser.read(1)

            if text:
                recv = text + self.__ser.readline()
                return recv.strip().strip('\n').strip('_')

    def FlushInput(self):
        self.__ser.flushInput()


if __name__ == '__main__':
    s = Serial('/dev/ttyUSB0')
    while True:

        try:
            j = json.loads(s.GetData())
            print '%s\t%s' %(time.time(), j)
        except:
            continue

運行，測試串口數據讀取正常

pi@raspberrypi:~/IoT/raspberrypi $ ./iot_serial.py
1506334420.2    {u'temperature': 17.4, u'humidness': 35.6}
1506334444.57   {u'temperature': 20.4, u'humidness': 46.4}
1506334468.19   {u'temperature': 20.4, u'humidness': 43.6}

將串口讀取數據利用MQTT協議發送

python安裝mqtt模塊：

sudo pip install paho-mqtt

編輯文件mqtt.py

#!/usr/bin/python
# -*- coding: utf-8 -*-

import time
import json
import traceback
import paho.mqtt.client as mqtt


from util import GetMacAddr
from iot_serial import Serial
from aliyun_iot import AliyunIot

#此處TOPIC應該替換為自己的
TOPIC = '/xxxxx/temperature_sensor/m2m'

def ConnectCallback(client, userdata, flags, rc):
    print 'Connected:' + str(rc)

dev_id = GetMacAddr()
print dev_id

a = AliyunIot()
conf = a.DeviceAuthentication(dev_id)
print conf

client = mqtt.Client(dev_id)
client.on_connect = ConnectCallback

client.tls_set('aliyun_iot.crt')
client.username_pw_set(conf['iotId'], conf['iotToken'])

m = conf['resources']['mqtt']
client.connect(m['host'], m['port'], 80)
client.loop_start()

s = Serial('/dev/ttyUSB0')
while True:
    try:
        msg = json.dumps(json.loads(s.GetData()))
        rc, mid = client.publish(TOPIC, payload=msg)
        if rc == 0:
            print '[%s]publis success, %s' %(time.strftime("%Y-%m-%d %H:%M:%S", time.localtime()), msg)
    except:
        traceback.print_exc()
    time.sleep(1)

運行查看結果：

pi@raspberrypi:~/IoT/raspberrypi $ ./mqtt.py
Connected:0
[2017-09-25 10:18:36]publis success, {"temperature": 17.2, "humidness": 45.6}

也可以在雲平台管理頁面查看日志：

設備間通信M2M

官方文檔：https://help.aliyun.com/document_detail/59147.html?spm=5176.doc30539.6.668.bSNXB3

配置規則引擎

訂閱Topic

#!/usr/bin/python
# -*- coding: utf-8 -*-

from util import GetMacAddr
from iot_serial import Serial
from aliyun_iot import AliyunIot
import paho.mqtt.client as mqtt

TOPIC = '/JVMwetHXFGK/temperature_sensor/m2m'

def ConnectCallback(client, userdata, flags, rc):
    print 'Connected:' + str(rc)
    client.subscribe(TOPIC)

def MessageCallback(client, userdata, msg):
    print '%s -> %s' %(msg.topic, str(msg.payload))

dev_id = GetMacAddr()
dev_id='test001'

a = AliyunIot('config_subscribe.json')
conf = a.DeviceAuthentication(dev_id)

client = mqtt.Client(dev_id)
client.on_connect = ConnectCallback
client.on_message = MessageCallback

client.tls_set('aliyun_iot.crt')
client.username_pw_set(conf['iotId'], conf['iotToken'])

m = conf['resources']['mqtt']
client.connect(m['host'], m['port'], 80)
client.loop_forever()

其中config_subscribe.json為配置文件拷貝一份，將里面的設備名和秘鑰改為另一個設備的。

運行發布消息和訂閱消息程序

數據存入表格存儲

創建規則

添加方法

沒有內容的可以按照提示連接創建

在OTS中查看數據

安裝表格存儲客戶端並登陸

總結

阿里雲Iot套件提供了方便的接入，便捷的數據導入其他雲服務，很適合大型、或海量應用高效接入。
對於智能家居方便，目前有比較好的開源平台Home Assistant可以自己搭建私有平台，且可以方便介入HomeKit等，效果非常贊。
下篇博客將簡單介紹Home Assistant相關內容。