arduino+esp8266+阿里云的代码

以下是一个简单的 Arduino ESP8266 连接阿里云的示例代码：

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

const char* ssid = "your_SSID";
const char* password = "your_PASSWORD";
const char* mqtt_server = "your_MQTT_SERVER";
const char* mqtt_user = "your_MQTT_USER";
const char* mqtt_password = "your_MQTT_PASSWORD";
const char* mqtt_topic = "your_MQTT_TOPIC";

WiFiClient espClient;
PubSubClient client(espClient);

void setup() {
Serial.begin(115200);
WiFi.begin(ssid, password);

while (WiFi.status() != WL_CONNECTED) {
delay(1000);
Serial.println("Connecting to WiFi...");
}

Serial.println("WiFi connected");
client.setServer(mqtt_server, 1883);
client.setCallback(callback);
}

void callback(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();
}

void reconnect() {
while (!client.connected()) {
Serial.print("Connecting to MQTT...");

if (client.connect("ESP8266Client", mqtt_user, mqtt_password)) {
Serial.println("connected");
client.subscribe(mqtt_topic);
} else {
Serial.print("failed, rc=");
Serial.print(client.state());
Serial.println(" try again in 5 seconds");
delay(5000);
}
}
}

void loop() {
if (!client.connected()) {
reconnect();
}

client.loop();
}

void sendData(float data) {
char payload[10];
String dataString = String(data);
dataString.toCharArray(payload, 10);
client.publish(mqtt_topic, payload);
}

// 主函数
void loop() {
float data = 123.456;
sendData(data);
delay(1000);
}

注意：你需要替换代码中的 SSID、密码、MQTT服务器信息和主题信息，以适应你自己的环境。此外，还需要下载和安装 PubSubClient 库。