51单片机使用mqty协议连接云平台程序
时间: 2023-06-10 19:06:48 浏览: 129
MQTT(Message Queuing Telemetry Transport)是一种轻量级的、开放式的、基于发布/订阅模式的消息传输协议,广泛用于物联网设备间的通信。下面是一个基于51单片机使用MQTT协议连接云平台的程序示例:
```c
#include <stdio.h>
#include <string.h>
#include "MQTTClient.h"
#define ADDRESS "tcp://localhost:1883"
#define CLIENTID "ExampleClientPub"
#define TOPIC "MQTT Examples"
#define PAYLOAD "Hello World!"
#define QOS 1
#define TIMEOUT 10000L
int main(int argc, char* argv[])
{
MQTTClient client;
MQTTClient_connectOptions conn_opts = MQTTClient_connectOptions_initializer;
MQTTClient_message pubmsg = MQTTClient_message_initializer;
MQTTClient_deliveryToken token;
int rc;
MQTTClient_create(&client, ADDRESS, CLIENTID, MQTTCLIENT_PERSISTENCE_NONE, NULL);
conn_opts.keepAliveInterval = 20;
conn_opts.cleansession = 1;
if ((rc = MQTTClient_connect(client, &conn_opts)) != MQTTCLIENT_SUCCESS)
{
printf("Failed to connect, return code %d\n", rc);
exit(-1);
}
pubmsg.payload = PAYLOAD;
pubmsg.payloadlen = strlen(PAYLOAD);
pubmsg.qos = QOS;
pubmsg.retained = 0;
MQTTClient_publishMessage(client, TOPIC, &pubmsg, &token);
printf("Waiting for up to %d seconds for publication of %s\n"
"on topic %s for client with ClientID: %s\n",
(int)(TIMEOUT/1000), PAYLOAD, TOPIC, CLIENTID);
rc = MQTTClient_waitForCompletion(client, token, TIMEOUT);
printf("Message with delivery token %d delivered\n", token);
MQTTClient_disconnect(client, 10000);
MQTTClient_destroy(&client);
return rc;
}
```
这是一个简单的MQTT发布程序示例。在这个例子中,我们使用MQTTClient库连接到本地的MQTT代理服务器,然后发布一个消息到名为“MQTT Examples”的主题中。其中,ADDRESS表示MQTT代理服务器的地址,CLIENTID是客户端ID,TOPIC是要发布的主题,PAYLOAD是要发布的消息内容,QOS是消息质量等级,TIMEOUT是等待发布确认的时间。在这个例子中,我们使用的是MQTTClient_publishMessage函数来发布一个消息,然后使用MQTTClient_waitForCompletion函数等待消息发布确认。最后,我们使用MQTTClient_disconnect函数断开连接,释放资源。