搭建一个物联网平台

#include <WiFi.h> #include <PubSubClient.h> #include <Arduino.h> #include <Ticker.h> #include <DFRobot_DHT11.h> #define clientId 'esp32' // id #define userName 'device' // username #define mqtt_password 'esp32wroom' // password #define BUILTIN_LED 13 #define DHT_PIN 17 void connectWifi(); void connectMQTTServer(); void subscribeTopic(); void publishTopic(String topic, String msg); void receiveCallback(char *topic, byte *payload, unsigned int length); void tickerContent(); String getDHTData(); const char *ssid = 'Redmi_91AE'; const char *password = '****'; const char *mqttServer = '192.168.31.108'; // const char *mqttServer = '183.230.40.39'; // oneNet // const char *mqttServer = 'mqtt.heclouds.com'; // oneNet // const uint16_t port = 6002; const uint16_t port = 1883; int count = 0; WiFiClient wifiClient; PubSubClient mqttClient(wifiClient); Ticker ticker; DFRobot_DHT11 dht; void setup() { Serial.begin(115200); pinMode(13, OUTPUT); WiFi.mode(WIFI_STA); connectWifi(); mqttClient.setServer(mqttServer, port); mqttClient.setCallback(receiveCallback); connectMQTTServer(); ticker.attach(1, tickerContent); } void loop() { if (mqttClient.connected()) { // 如果开发板成功连接服务器 mqttClient.loop(); // 保持客户端心跳 } else { // 如果开发板未能成功连接服务器 connectMQTTServer(); // 则尝试连接服务器 } if (count >=60 ) { count = 0; // publishTopic(); publishTopic('data/temperature_data', getDHTData()); // Serial.println(getDHTData()); } } // 连接mqtt服务器 void connectMQTTServer() { if (WiFi.isConnected()) { if (mqttClient.connect(clientId, userName, mqtt_password)) { Serial.println('MQTT Server Connected.'); Serial.println('Server Address: '); Serial.println(mqttServer); Serial.println('ClientId:'); Serial.println(clientId); subscribeTopic(); } else { Serial.print('MQTT Server Connect Failed. Client State:'); Serial.println(mqttClient.state()); delay(3000); } } else { connectWifi(); } } // 连接wifi void connectWifi() { WiFi.begin(ssid, password); while (WiFi.status() != WL_CONNECTED) { delay(1000); Serial.print('.'); } Serial.println(''); Serial.println('WiFi Connected!'); Serial.println(''); } // 订阅 topic void subscribeTopic() { String topic = 'command/LED_Switch'; if (mqttClient.subscribe(topic.c_str())) { Serial.println('Subscrib Topic:'); Serial.println(topic); } else { Serial.print('Subscribe Fail...'); } } // 发布数据 void publishTopic(String topic, String msg) { if (mqttClient.publish(topic.c_str(), msg.c_str())) { Serial.println('Publish Topic:'); Serial.println(topic); Serial.println('Publish message:'); Serial.println(msg); } else { Serial.println('Message Publish Failed.'); } } // 收到消息后的回调函数 void receiveCallback(char *topic, byte *payload, unsigned int length) { Serial.print('Message Received ['); Serial.print(topic); Serial.print('] '); for (int i = 0; i < length; i++) { Serial.print((char)payload[i]); } Serial.println(''); Serial.print('Message Length(Bytes) '); Serial.println(length); if (strcmp(topic, 'command/LED_Switch') == 0) { if ((char)payload[0] == '1') { // 如果收到的信息以“1”为开始 digitalWrite(BUILTIN_LED, HIGH); // 则点亮LED。 Serial.println('LED ON'); } else { digitalWrite(BUILTIN_LED, LOW); // 否则熄灭LED。 Serial.println('LED OFF'); } } else { Serial.println('else'); // 默认指令 topic } } void tickerContent() { count++; } String getDHTData() { dht.read(DHT_PIN); return ' { \'temperature\' : ' + String(dht.temperature) + ', \'humidity\': ' + String(dht.humidity) + '}'; }