arduino uno采取mqtt协议连接云平台设备的代码

以下是arduino uno采取mqtt协议连接云平台设备的代码示例：

#include <PubSubClient.h>
#include <WiFi.h>

// 需要输入WiFi网络的SSID和密码
const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";

// 设备的ID和访问密钥，需要替换成自己的
const char* device_id = "your_DEVICE_ID";
const char* access_key = "your_ACCESS_KEY";

// 云平台MQTT服务器的IP地址和端口号，需要替换成自己的
const char* mqtt_server = "your_MQTT_SERVER_IP";
int mqtt_port = your_MQTT_SERVER_PORT;

// MQTT客户端
WiFiClient wifi_client;
PubSubClient mqtt_client(wifi_client);

void setup() {
// 初始化串口
Serial.begin(9600);

// 连接WiFi
WiFi.begin(ssid, password);
while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}
Serial.println("WiFi connected");

// 连接MQTT
mqtt_client.setServer(mqtt_server, mqtt_port);
while (!mqtt_client.connected()) {
if (mqtt_client.connect(device_id, access_key, "")) {
Serial.println("MQTT connected");
} else {
Serial.print("MQTT connection failed, rc=");
Serial.println(mqtt_client.state());
delay(5000);
}
}
}

void loop() {
// 持续连接MQTT
if (!mqtt_client.connected()) {
mqtt_client.connect(device_id, access_key, "");
}
mqtt_client.loop();

// 发布消息到MQTT主题
mqtt_client.publish("your_MQTT_TOPIC", "Hello, world!");
delay(1000);
}