Contiki os MQTT

#include "contiki.h"
#include "libmqtt.h"

#define MQTT_BROKER "broker.hivemq.com"
#define MQTT_PORT 1883
#define CLIENT_ID "contiki-mqtt-client"

PROCESS(mqtt_example_process, "MQTT Example Process");
AUTOSTART_PROCESSES(&mqtt_example_process);

PROCESS_THREAD(mqtt_example_process, ev, data) {
  PROCESS_BEGIN();

  // 初始化 MQTT 客户端
  struct mqtt_client client;
  mqtt_client_init(&client, MQTT_BROKER, MQTT_PORT, CLIENT_ID);

  // 连接到 MQTT 代理
  if (mqtt_connect(&client) != MQTT_OK) {
    printf("Failed to connect to MQTT broker
");
    PROCESS_END();
  }

  // 订阅主题
  if (mqtt_subscribe(&client, "test/topic") != MQTT_OK) {
    printf("Failed to subscribe to topic
");
    mqtt_disconnect(&client);
    PROCESS_END();
  }

  // 发布消息
  const char *message = "Hello, MQTT!";
  if (mqtt_publish(&client, "test/topic", message, strlen(message)) != MQTT_OK) {
    printf("Failed to publish message
");
  }

  // 断开连接
  mqtt_disconnect(&client);

  PROCESS_END();
}