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上次給大家分享了如何使用ESP32實現藍牙通信，今天跟大家聊聊如何使用ESP32連接騰訊云實現遠程控制。本次實驗用到MQTT協議，同樣，我用miropython編寫程序實現，最終可以通過騰訊連連微信小程序添加設備來發布主題消息給騰訊云，ESP32負責訂閱騰訊云主題消息，當收到某訂閱消息時，來控制ESP32設備上LED燈的亮滅。

第一步、創建騰訊云產品和設備

瀏覽器搜索【騰訊云】，進入騰訊云官網，微信注冊登錄

點擊【產品】搜索【物聯網開發平臺】，點擊【管理控制臺】

在實例管理中點擊【公共實例】

點擊【新建項目】

填寫自己的項目名稱，點擊【保存】

點擊剛新建的項目

點擊【新建產品】

輸入自己定義的【產品名稱】，【產品類別】選智慧城市->公共事業->路燈照明，【通信設備】填wi-fi，其他的默認，點擊【確定】

點擊自己剛新建的產品名稱

下拉到最后點擊【下一步】

點擊【基于模組開發】，產品平臺選擇【樂鑫】，類型選擇【wifi】，點擊【樂鑫ESP-WROOM-】點擊【確定】

下拉到最后，點擊【下一步】

點擊【產品展示配置】右側的【配置】

【產品展示名稱】填寫自己自定義的名稱，【廠家名稱】填安信可，【產品信號】填esp32,點擊【保存】，上拉點擊【<-】返回

點擊【快捷入口配置】右側的【配置】，默認不修改，點擊【保存】，上拉點擊【<-】返回

點擊【面板配置】右側的【配置】，默認不修改，點擊【保存】，點擊【<-】返回

點擊【配網引導】右側的【配置】，【芯片方案選擇】選擇樂鑫，【首選配網方式】選擇Smart Config,【次配網方式】選擇Soft Ap,點擊；【保存】，點擊【<-】返回

點擊【掃一掃產品介紹】右側的【配置】，默認不修改，點擊【保存】，點擊【<-】返回

點擊【智能聯動配置】右側的【配置】，默認不修改，點擊保存，點擊【<-】返回

點擊【下一步】

點擊【新建設備】，自定義【設備名稱】，點擊【保存】

點擊【二維碼】，用手機微信小程序【騰訊連連】掃碼添加設備

此時設備已經創建完成，但是設備還未激活，需要后面的的操作連接才可激活

第二步：生成Username和Password

點擊【設備調試】，點擊【設備名稱】

復制保存設備信息三件套：設備名稱、產品ID、設備密鑰

后面生成MOTT協議中的Username和Password需要用到

打開password生成工具，在文件夾里有給出，點擊【sign.html】

輸入剛剛復制的設備信息三件套，Hmac簽名算法選擇【HMAC-SHA1】，點擊【Generate】，即可生成Usename和Password,復制保存，后面esp32連接騰訊云和MQTTfx模擬的客戶端連接騰訊云需要用到

第三步：MQTTfx模擬客戶端連接騰訊云步驟與調試（非必須步驟）

打開MQTT.fx軟件，我的壓縮包里面有，點擊下圖的齒輪圖形，進入設置

【Profile name】:自定義的名字

【Profile Type】:選擇【MQTT Broker】

【Broker Address】:騰訊云三件套中的產品ID+.iotcloud.tencentdevices.com

如我的騰訊云ID為：D89S2VVAFT，

那么Broker Address為：D89S2VVAFT.iotcloud.tencentdevices.com

Broker Port:1883

【Client ID】:騰訊云產品ID+騰訊云設備名稱+|securemode=3,signmethod=hmacsha1|

例如我的騰訊云產品ID為：D89S2VVAFT，騰訊云產品名稱為：esp_led

則Client ID為：D89S2VVAFTesp_led|securemode=3,signmethod=hmacsha1|

填寫這些數據完畢后，點擊【User Credentlals】

User Name和Password填寫第二步生成的，每個人的都不一樣

【User Name】:D89S2VVAFTesp_led;12010126;CU7SQ;1660090317

【Password】:cd6c31a3d4cfdba2759deab02fb831a0f672e008;hmacsha1

點擊【OK】保存

點擊【Connect】連接騰訊云

MQTT.fx模擬的客戶端連接騰訊云成功后可以看到右邊的原點變綠，并且有個打開的所，

這時候我們就可以通過手機端小程序騰訊連連來給騰訊云發送消息，騰訊云再將此消息發送給MQTT.fx客戶端，但是前提是MQTT.fx客戶端需要訂閱騰訊云，下面是訂閱的步驟

點擊【Subscribe】，Subscribe左邊的空格填寫格式為：

$thing/down/property/“騰訊云產品ID”/“騰訊云產品名稱”

例如：$thing/down/property/D89S2VVAFT/esp_led

填寫完成后，點擊【Subscribe】，現在手機端騰訊練練發送消息，MQTT.fx可以收到消息了

可以看到MQTT.fx收到了消息，MQTT.fx只是模擬一個客戶端接收消息，我們需要將我們的esp32模塊替代MQTT.fx，這樣我們就可以通過手機發送消息給騰訊云，騰訊云轉發消息給esp32模塊了，通過單片機對收到的數據處理，就可以通過手機端控制開發板的LED燈亮滅。

第四步、編寫程序代碼

首先需要用到MQTT的驅動代碼，我在網上找到了一個用miropython寫的驅動代碼，大家可以直接復制使用，命名為umqttsimple.py即可，代碼如下：

import usocket as socket
import ustruct as struct
from ubinascii import hexlify




class MQTTException(Exception):
    pass




class MQTTClient:
    def __init__(
        self,
        client_id,
        server,
        port=0,
        user=None,
        password=None,
        keepalive=0,
        ssl=False,
        ssl_params={},
    ):
        if port == 0:
            port = 8883 if ssl else 1883
        self.client_id = client_id
        self.sock = None
        self.server = server
        self.port = port
        self.ssl = ssl
        self.ssl_params = ssl_params
        self.pid = 0
        self.cb = None
        self.user = user
        self.pswd = password
        self.keepalive = keepalive
        self.lw_topic = None
        self.lw_msg = None
        self.lw_qos = 0
        self.lw_retain = False


    def _send_str(self, s):
        self.sock.write(struct.pack("!H", len(s)))
        self.sock.write(s)


    def _recv_len(self):
        n = 0
        sh = 0
        while 1:
            b = self.sock.read(1)[0]
            n |= (b & 0x7F) << sh
            if not b & 0x80:
                return n
            sh += 7


    def set_callback(self, f):
        self.cb = f


    def set_last_will(self, topic, msg, retain=False, qos=0):
        assert 0 <= qos <= 2
        assert topic
        self.lw_topic = topic
        self.lw_msg = msg
        self.lw_qos = qos
        self.lw_retain = retain


    def connect(self, clean_session=True):
        self.sock = socket.socket()
        addr = socket.getaddrinfo(self.server, self.port)[0][-1]
        self.sock.connect(addr)
        if self.ssl:
            import ussl


            self.sock = ussl.wrap_socket(self.sock, **self.ssl_params)
        premsg = bytearray(b"x10")
        msg = bytearray(b"x04MQTTx04x02")


        sz = 10 + 2 + len(self.client_id)
        msg[6] = clean_session << 1
        if self.user is not None:
            sz += 2 + len(self.user) + 2 + len(self.pswd)
            msg[6] |= 0xC0
        if self.keepalive:
            assert self.keepalive < 65536
            msg[7] |= self.keepalive >> 8
            msg[8] |= self.keepalive & 0x00FF
        if self.lw_topic:
            sz += 2 + len(self.lw_topic) + 2 + len(self.lw_msg)
            msg[6] |= 0x4 | (self.lw_qos & 0x1) << 3 | (self.lw_qos & 0x2) << 3
            msg[6] |= self.lw_retain << 5


        i = 1
        while sz > 0x7F:
            premsg[i] = (sz & 0x7F) | 0x80
            sz >>= 7
            i += 1
        premsg[i] = sz


        self.sock.write(premsg, i + 2)
        self.sock.write(msg)
        # print(hex(len(msg)), hexlify(msg, ":"))
        self._send_str(self.client_id)
        if self.lw_topic:
            self._send_str(self.lw_topic)
            self._send_str(self.lw_msg)
        if self.user is not None:
            self._send_str(self.user)
            self._send_str(self.pswd)
        resp = self.sock.read(4)
        assert resp[0] == 0x20 and resp[1] == 0x02
        if resp[3] != 0:
            raise MQTTException(resp[3])
        return resp[2] & 1


    def disconnect(self):
        self.sock.write(b"xe0")
        self.sock.close()


    def ping(self):
        self.sock.write(b"xc0")


    def publish(self, topic, msg, retain=False, qos=0):
        pkt = bytearray(b"x30")
        pkt[0] |= qos << 1 | retain
        sz = 2 + len(topic) + len(msg)
        if qos > 0:
            sz += 2
        assert sz < 2097152
        i = 1
        while sz > 0x7F:
            pkt[i] = (sz & 0x7F) | 0x80
            sz >>= 7
            i += 1
        pkt[i] = sz
        # print(hex(len(pkt)), hexlify(pkt, ":"))
        self.sock.write(pkt, i + 1)
        self._send_str(topic)
        if qos > 0:
            self.pid += 1
            pid = self.pid
            struct.pack_into("!H", pkt, 0, pid)
            self.sock.write(pkt, 2)
        self.sock.write(msg)
        if qos == 1:
            while 1:
                op = self.wait_msg()
                if op == 0x40:
                    sz = self.sock.read(1)
                    assert sz == b"x02"
                    rcv_pid = self.sock.read(2)
                    rcv_pid = rcv_pid[0] << 8 | rcv_pid[1]
                    if pid == rcv_pid:
                        return
        elif qos == 2:
            assert 0


    def subscribe(self, topic, qos=0):
        assert self.cb is not None, "Subscribe callback is not set"
        pkt = bytearray(b"x82")
        self.pid += 1
        struct.pack_into("!BH", pkt, 1, 2 + 2 + len(topic) + 1, self.pid)
        # print(hex(len(pkt)), hexlify(pkt, ":"))
        self.sock.write(pkt)
        self._send_str(topic)
        self.sock.write(qos.to_bytes(1, "little"))
        while 1:
            op = self.wait_msg()
            if op == 0x90:
                resp = self.sock.read(4)
                # print(resp)
                assert resp[1] == pkt[2] and resp[2] == pkt[3]
                if resp[3] == 0x80:
                    raise MQTTException(resp[3])
                return


    # Wait for a single incoming MQTT message and process it.
    # Subscribed messages are delivered to a callback previously
    # set by .set_callback() method. Other (internal) MQTT
    # messages processed internally.
    def wait_msg(self):
        res = self.sock.read(1)
        self.sock.setblocking(True)
        if res is None:
            return None
        if res == b"":
            raise OSError(-1)
        if res == b"xd0":  # PINGRESP
            sz = self.sock.read(1)[0]
            assert sz == 0
            return None
        op = res[0]
        if op & 0xF0 != 0x30:
            return op
        sz = self._recv_len()
        topic_len = self.sock.read(2)
        topic_len = (topic_len[0] << 8) | topic_len[1]
        topic = self.sock.read(topic_len)
        sz -= topic_len + 2
        if op & 6:
            pid = self.sock.read(2)
            pid = pid[0] << 8 | pid[1]
            sz -= 2
        msg = self.sock.read(sz)
        self.cb(topic, msg)
        if op & 6 == 2:
            pkt = bytearray(b"x40x02")
            struct.pack_into("!H", pkt, 2, pid)
            self.sock.write(pkt)
        elif op & 6 == 4:
            assert 0


    # Checks whether a pending message from server is available.
    # If not, returns immediately with None. Otherwise, does
    # the same processing as wait_msg.
    def check_msg(self):
        self.sock.setblocking(False)
        return self.wait_msg()

主程序代碼如下：

import time
import network
from umqttsimple import MQTTClient
from machine import Pin,Timer


def do_connect():
    wlan = network.WLAN(network.STA_IF)
    wlan.active(True)
    if not wlan.isconnected():
        print('connecting to network...')
        wlan.connect('11', '1234567a')
        i = 1
        while not wlan.isconnected():
            print("正在鏈接...{}".format(i))
            i += 1
            time.sleep(1)
    print('network config:', wlan.ifconfig())




def sub_cb(topic, msg): # 回調函數，收到服務器消息后會調用這個函數
    print(topic, msg)
    top=str(topic,'UTF-8')
    strdata=str(msg,'UTF-8')
    count=strdata.find("power_switch")
    print(strdata[count+len("power_switch")+2])
    if strdata[count+len("power_switch")+2]=='0' and top=='$thing/down/property/D89S2VVAFT/esp_led':
        led.value(1)
    if strdata[count+len("power_switch")+2]=='1' and top=='$thing/down/property/D89S2VVAFT/esp_led':
        led.value(0)
        
#客戶端ID    
client_id="D89S2VVAFTesp_led|securemode=3,signmethod=hmacsha1|"
#服務器域名
addr="D89S2VVAFT.iotcloud.tencentdevices.com"
#端口號
port=1883
#用戶名
username="D89S2VVAFTesp_led;12010126;KTXHT;1669512546"
#密碼
password="0569df86e0c75494960cc922703c9ddd47c3fee048ed03d6b1a22d89a8b8a305;hmacsha256"




led=Pin(22,Pin.OUT)
led.value(1)
# 1. 聯網
do_connect()
# 2. 創建mqt
c = MQTTClient(client_id=client_id,server=addr,port=port,user=username,password=password,keepalive=60)  # 建立一個MQTT客戶端
c.set_callback(sub_cb)  # 設置回調函數
c.connect()  # 建立連接
c.subscribe(b"$thing/down/property/D89S2VVAFT/esp_led")  # 監控ledctl這個通道，接收控制命令
timer1 = Timer(0)
timer1.init(period=1000*60, mode=Timer.PERIODIC, callback=lambda t: c.ping())
while True:
    c.check_msg()

點擊編譯，編譯成功如下

查看騰訊云建立的設備，可以看到，此時設備已經在線

點擊二維碼，打開騰訊連連小程序，掃碼添加設備

現在就可以通過騰訊連連來控制ESP32設備啦！點擊點燈開關，ESP32設備打印出收到的消息，如下：

審核編輯：湯梓紅