ESP8266通過MQTT上傳數據（阿里雲）

1.EMQ上連接服務器，主機地址填ESP8266上傳數據的服務器公網地址，等會在ESP8266的代碼段上可以看見相應的主機地址。

 

 2.訂閱ESP8266上的相同的topic（ESP作為Sub，EMQ作為Pub）

 

 

 3.上傳代碼給ESP8266，上傳完成即實現向阿里雲傳輸數據，下面步驟是利用python將數據寫入txt文件並保存到本地

ssid為WiFi名

password 為WiFi密碼

#include <ESP8266WiFi.h>
#include <PubSubClient.h>
#include <DHT.h>

//esp8266引腳

#define D0  16
#define D1  5
#define D2  4
#define D3  0
#define D4  2
#define D5  14
#define D6  12
#define D7  13
#define D8  15
#define D9  3
#define D10  1


const char* ssid = "Xiaomi_C6F4";
const char* password = "10241024";
//填入公網地址如192.168.0.0這樣的不用加http這些前綴
const char* mqtt_server = ""; // 使用HIVEMQ 的信息中轉服務


const char* TOPIC = "/test/msg/";                     // 訂閱信息主題
const char* client_id = "Mymqtt";                   // 標識當前設備的客戶端編號，隨便填

float RH,T;
DHT dht(D3,DHT11, 15); //溫濕度引腳
WiFiClient espClient;                                                         // 定義wifiClient實例
PubSubClient client(espClient);                                         // 定義PubSubClient的實例
long lastMsg = 0;                                                               // 記錄上一次發送信息的時長

void setup() {

  dht.begin();
  Serial.begin(115200); 
  setup_wifi();                                                                    //執行Wifi初始化，下文有具體描述
  client.setServer(mqtt_server, 1883);                              //設定MQTT服務器與使用的端口，1883是默認的MQTT端口
  client.setCallback(callback);                                          //設定回調方式，當ESP8266收到訂閱消息時會調用此方法
}

void setup_wifi() {

  delay(10);
  // 板子通電后要啟動，稍微等待一下讓板子點亮
  Serial.println();
  Serial.print("Connecting to ");
  Serial.println(ssid);

  WiFi.begin(ssid, password);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }

  Serial.println("");
  Serial.println("WiFi connected");
  Serial.println("IP address: ");
  Serial.println(WiFi.localIP());
}

void callback(char* topic, byte* payload, unsigned int length) {
  Serial.print("Message arrived [");
  Serial.print(topic);   // 打印主題信息
  Serial.print("] ");
  for (int i = 0; i < length; i++) {
    Serial.print((char)payload[i]); // 打印主題內容
  }
  Serial.println();
  
}

void reconnect() {
  while (!client.connected()) {
    Serial.print("Attempting MQTT connection...");
    // Attempt to connect
    if (client.connect(client_id)) {
      Serial.println("connected");
      // 連接成功時訂閱主題
      client.subscribe(TOPIC);
    } else {
      Serial.print("failed, rc=");
      Serial.print(client.state());
      Serial.println(" try again in 5 seconds");
      // Wait 5 seconds before retrying
      delay(5000);
    }
  }
}

void loop() {

  if (!client.connected()) {
    reconnect();
  }
  client.loop();
   RH = dht.readHumidity();   //讀取濕度數據                       
   T = dht.readTemperature();       //讀取溫度數據
//   RH_sum+=RH;
//   T_sum+=T;                    
  long now = millis();
  if (now - lastMsg > 3000) {
    lastMsg = now;
    String msg = "Tempature: " + (String)T + "Humidity: " + (String)RH;
    client.publish("/test/msg/", msg.c_str());//"'temperature':26,'Humidity':30"
  }
}

連線圖

 

 4.利用python程序讀取

import paho.mqtt.client as mqtt
import time 
MQTTHOST = ""
MQTTPORT = 1883
mqttClient = mqtt.Client()
 
 
# 連接MQTT服務器
def on_mqtt_connect():
    mqttClient.connect(MQTTHOST, MQTTPORT, 60)
    mqttClient.loop_start()
 
 
# publish 消息
def on_publish(topic, payload, qos):
    mqttClient.publish(topic, payload, qos)
 
# 消息處理函數
def on_message_come(lient, userdata, msg):
    
    string = msg.topic + " " + ":" + str(msg.payload)
    data = open(r"test.txt","w")
    data.write(string)
    data.close()
    time.sleep(5)
    print(string)

 
 
# subscribe 消息
def on_subscribe():
    mqttClient.subscribe("/test/msg/", 0)
    mqttClient.on_message = on_message_come # 消息到來處理函數
 
 
def main():
    on_mqtt_connect()
    on_publish("/test/server", "Hello Python!", 1)
    on_subscribe()
    while True:
        pass
 
 
 
if __name__ == '__main__':
    main()

 

效果圖

 

text.txt文件里面的數據一直在變化，可以進行數據的讀取以及其他操作