1.EMQ上连接服务器,主机地址填ESP8266上传数据的服务器公网地址,等会在ESP8266的代码段上可以看见相应的主机地址。
2.订阅ESP8266上的相同的topic(ESP作为Sub,EMQ作为Pub)
3.上传代码给ESP8266,上传完成即实现向阿里云传输数据,下面步骤是利用python将数据写入txt文件并保存到本地
ssid为WiFi名
password 为WiFi密码
#include <ESP8266WiFi.h> #include <PubSubClient.h> #include <DHT.h> //esp8266引脚 #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";
//填入公网地址如192.168.0.0这样的不用加http这些前缀 const char* mqtt_server = ""; // 使用HIVEMQ 的信息中转服务
const char* TOPIC = "/test/msg/"; // 订阅信息主题 const char* client_id = "Mymqtt"; // 标识当前设备的客户端编号,随便填 float RH,T; DHT dht(D3,DHT11, 15); //温湿度引脚 WiFiClient espClient; // 定义wifiClient实例 PubSubClient client(espClient); // 定义PubSubClient的实例 long lastMsg = 0; // 记录上一次发送信息的时长 void setup() { dht.begin(); Serial.begin(115200); setup_wifi(); //执行Wifi初始化,下文有具体描述 client.setServer(mqtt_server, 1883); //设定MQTT服务器与使用的端口,1883是默认的MQTT端口 client.setCallback(callback); //设定回调方式,当ESP8266收到订阅消息时会调用此方法 } void setup_wifi() { delay(10); // 板子通电后要启动,稍微等待一下让板子点亮 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); // 打印主题信息 Serial.print("] "); for (int i = 0; i < length; i++) { Serial.print((char)payload[i]); // 打印主题内容 } Serial.println(); } void reconnect() { while (!client.connected()) { Serial.print("Attempting MQTT connection..."); // Attempt to connect if (client.connect(client_id)) { Serial.println("connected"); // 连接成功时订阅主题 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(); //读取湿度数据 T = dht.readTemperature(); //读取温度数据 // 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" } }
连线图
4.利用python程序读取
import paho.mqtt.client as mqtt import time MQTTHOST = "" MQTTPORT = 1883 mqttClient = mqtt.Client() # 连接MQTT服务器 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) # 消息处理函数 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 # 消息到来处理函数 def main(): on_mqtt_connect() on_publish("/test/server", "Hello Python!", 1) on_subscribe() while True: pass if __name__ == ‘__main__‘: main()
效果图
text.txt文件里面的数据一直在变化,可以进行数据的读取以及其他操作