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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(xié)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(fā)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(chuàng)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(lián)網開發(fā)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(yè)->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(fā)】，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(lián)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(chuàng)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(xié)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(fā)送消息，騰訊云再將此消息發(fā)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(fā)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(fā)送消息給騰訊云，騰訊云轉發(fā)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(fā)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(lián)網
do_connect()
# 2. 創(chuàng)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(jiān)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