51单片机连接阿里云代码

以下是51单片机连接阿里云的示例代码：

#include <stdio.h>
#include <string.h>
#include <stdlib.h>
#include <reg52.h>

/**********************阿里云设备信息************************/
//设备三元组
#define PRODUCT_KEY "your_product_key"
#define DEVICE_NAME "your_device_name"
#define DEVICE_SECRET "your_device_secret"

//MQTT服务器地址和端口
#define MQTT_SERVER_HOST "your_mqtt_server_host"
#define MQTT_SERVER_PORT 1883

//发布和订阅的主题
#define SUB_TOPIC "/sys/"DEVICE_NAME"/"PRODUCT_KEY"/thing/service/property/set" //订阅主题
#define PUB_TOPIC "/sys/"DEVICE_NAME"/"PRODUCT_KEY"/thing/event/property/post" //发布主题

//MQTT客户端ID和用户名密码
#define MQTT_CLIENT_ID DEVICE_NAME"@@@12345"
#define MQTT_USERNAME PRODUCT_KEY"&"DEVICE_NAME
#define MQTT_PASSWORD "1234567890ABCDEF"

/**********************阿里云设备信息************************/

#define uchar unsigned char
#define uint unsigned int

sbit LED = P1^0; //控制LED的IO口

//串口通信相关变量
uchar RX_Buffer[32]; //串口接收缓冲区
uchar RX_Count = 0; //串口接收计数器
bit RX_Flag = 0; //串口接收完成标志

//MQTT相关变量
uchar MQTT_Send_Buffer[128]; //MQTT发送缓冲区
uchar MQTT_Rev_Buffer[128]; //MQTT接收缓冲区
uint MQTT_Send_Len = 0; //MQTT发送数据长度
uint MQTT_Rev_Len = 0; //MQTT接收数据长度
bit MQTT_Connect_Flag = 0; //MQTT连接状态标志

//函数声明
void Init_Timer0(void);
void Init_UART(void);
void UART_SendByte(uchar dat);
void UART_SendString(uchar *str);
void MQTT_Connect(void);
void MQTT_Subscribe(void);
void MQTT_Publish(uchar *payload);

void main()
{
    EA = 1; //开启总中断
    Init_Timer0(); //初始化定时器0
    Init_UART(); //初始化串口

    while(1)
    {
        if(RX_Flag) //如果串口接收完成
        {
            RX_Flag = 0; //清除串口接收完成标志
            if(strncmp(RX_Buffer, "LED_ON", 6) == 0) //如果接收到"LED_ON"指令
            {
                LED = 0; //点亮LED
                MQTT_Publish("LED_ON"); //发布LED状态
            }
            else if(strncmp(RX_Buffer, "LED_OFF", 7) == 0) //如果接收到"LED_OFF"指令
            {
                LED = 1; //熄灭LED
                MQTT_Publish("LED_OFF"); //发布LED状态
            }
            memset(RX_Buffer, 0, sizeof(RX_Buffer)); //清空串口接收缓冲区
            RX_Count = 0; //清空串口接收计数器
        }
    }
}

//定时器0初始化函数
void Init_Timer0(void)
{
    TMOD |= 0x01; //定时器0工作在模式1
    TH0 = 0xFC; //定时器初值
    TL0 = 0x67;
    ET0 = 1; //开启定时器0中断
    TR0 = 1; //启动定时器0
}

//定时器0中断函数
void Timer0_ISR() interrupt 1
{
    TH0 = 0xFC; //重新赋初值
    TL0 = 0x67;
}

//串口初始化函数
void Init_UART(void)
{
    TMOD &= 0x0F; //使用定时器1的模式2
    TMOD |= 0x20;
    SCON = 0x50; //串口工作在模式1
    TH1 = 0xFD; //波特率9600
    TL1 = 0xFD;
    ET1 = 0; //禁用定时器1中断
    ES = 1; //开启串口中断
    TR1 = 1; //启动定时器1
}

//串口发送一个字节
void UART_SendByte(uchar dat)
{
    SBUF = dat;
    while(!TI); //等待发送完成
    TI = 0; //清除发送完成标志
}

//串口发送一个字符串
void UART_SendString(uchar *str)
{
    while(*str)
    {
        UART_SendByte(*str++);
    }
}

//MQTT连接函数
void MQTT_Connect(void)
{
    memset(MQTT_Send_Buffer, 0, sizeof(MQTT_Send_Buffer)); //清空发送缓冲区
    MQTT_Send_Buffer[0] = 0x10; //MQTT连接请求标志
    MQTT_Send_Buffer[1] = 0x1F; //MQTT报文固定头部长度
    MQTT_Send_Buffer[2] = 0x00; //MQTT协议名长度
    MQTT_Send_Buffer[3] = 0x06;
    MQTT_Send_Buffer[4] = 'M';
    MQTT_Send_Buffer[5] = 'Q';
    MQTT_Send_Buffer[6] = 'T';
    MQTT_Send_Buffer[7] = 'T';
    MQTT_Send_Buffer[8] = '3';
    MQTT_Send_Buffer[9] = '1';
    MQTT_Send_Buffer[10] = 0x04; //MQTT协议级别
    MQTT_Send_Buffer[11] = 0xC2; //MQTT连接标志
    MQTT_Send_Buffer[12] = 0x00; //MQTT心跳周期
    MQTT_Send_Buffer[13] = 0x3C;
    MQTT_Send_Buffer[14] = 0x00; //MQTT客户端ID长度
    MQTT_Send_Buffer[15] = 0x0D;
    MQTT_Send_Buffer[16] = 'A'; //MQTT客户端ID
    MQTT_Send_Buffer[17] = 'L';
    MQTT_Send_Buffer[18] = 'I';
    MQTT_Send_Buffer[19] = '_';
    MQTT_Send_Buffer[20] = 'M';
    MQTT_Send_Buffer[21] = 'Q';
    MQTT_Send_Buffer[22] = 'T';
    MQTT_Send_Buffer[23] = 'T';
    MQTT_Send_Buffer[24] = '_';
    MQTT_Send_Buffer[25] = 'E';
    MQTT_Send_Buffer[26] = 'M';
    MQTT_Send_Buffer[27] = 'B';
    MQTT_Send_Buffer[28] = 'E';
    MQTT_Send_Buffer[29] = 'D';
    MQTT_Send_Buffer[30] = 0xC0; //MQTT遗嘱标志
    MQTT_Send_Buffer[31] = 0x00; //MQTT遗嘱QoS
    MQTT_Send_Buffer[32] = 0x00; //MQTT遗嘱主题长度
    MQTT_Send_Buffer[33] = 0x00;
    MQTT_Send_Buffer[34] = 0x00; //MQTT遗嘱消息长度
    MQTT_Send_Buffer[35] = 0x00;

    MQTT_Send_Len = 36; //MQTT连接请求长度

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+TCLOSE\r\n"); //关闭TCP连接

    delay_ms(1000);

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+CGATT?\r\n"); //查询GPRS网络状态

    delay_ms(1000);

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+NETOPEN\r\n"); //打开GPRS网络

    delay_ms(5000);

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+IPSTATUS\r\n"); //查询IP地址

    delay_ms(1000);

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+MQTTDISC\r\n"); //断开MQTT连接

    delay_ms(1000);

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+MQTTCONN?\r\n"); //查询MQTT连接状态

    delay_ms(1000);

    memset(MQTT_Rev_Buffer, 0, sizeof(MQTT_Rev_Buffer)); //清空接收缓冲区
    MQTT_Rev_Len = 0; //清空接收数据长度

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+MQTTCONN="); //连接MQTT服务器
    UART_SendString("\"tcp://");
    UART_SendString(MQTT_SERVER_HOST);
    UART_SendByte(':');
    UART_SendByte(MQTT_SERVER_PORT/256);
    UART_SendByte(MQTT_SERVER_PORT%256);
    UART_SendString("\",\"");
    UART_SendString(MQTT_CLIENT_ID);
    UART_SendString("\",\"");
    UART_SendString(MQTT_USERNAME);
    UART_SendString("\",\"");
    UART_SendString(MQTT_PASSWORD);
    UART_SendString("\"\r\n");

    delay_ms(5000);

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+MQTTCONN?\r\n"); //查询MQTT连接状态

    delay_ms(1000);

    if(strstr(MQTT_Rev_Buffer, "CONNECTED") != NULL) //如果连接成功
    {
        MQTT_Connect_Flag = 1; //设置连接状态标志
        MQTT_Subscribe(); //订阅主题
    }
    else
    {
        MQTT_Connect_Flag = 0; //连接失败，清除连接状态标志
    }
}

//MQTT订阅函数
void MQTT_Subscribe(void)
{
    memset(MQTT_Send_Buffer, 0, sizeof(MQTT_Send_Buffer)); //清空发送缓冲区
    MQTT_Send_Buffer[0] = 0x82; //MQTT订阅请求标志
    MQTT_Send_Buffer[1] = 0x0C; //MQTT报文固定头部长度
    MQTT_Send_Buffer[2] = 0x00; //MQTT报文标识符高位
    MQTT_Send_Buffer[3] = 0x01; //MQTT报文标识符低位
    MQTT_Send_Buffer[4] = 0x00; //MQTT主题长度高位
    MQTT_Send_Buffer[5] = strlen(SUB_TOPIC); //MQTT主题长度低位
    memcpy(&MQTT_Send_Buffer[6], SUB_TOPIC, strlen(SUB_TOPIC)); //MQTT主题
    MQTT_Send_Buffer[6+strlen(SUB_TOPIC)] = 0x00; //MQTT订阅QoS

    MQTT_Send_Len = 7+strlen(SUB_TOPIC); //MQTT订阅请求长度

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+MQTTSUB="); //订阅主题
    UART_SendByte(MQTT_Send_Len/256);
    UART_SendByte(MQTT_Send_Len%256);
    UART_SendByte(0x01); //MQTT订阅请求标志
    UART_SendString("\r\n");
    for(uint i=0; i<MQTT_Send_Len; i++)
    {
        UART_SendByte(MQTT_Send_Buffer[i]); //发送MQTT订阅请求
    }

    delay_ms(1000);
}

//MQTT发布函数
void MQTT_Publish(uchar *payload)
{
    if(!MQTT_Connect_Flag) //如果MQTT未连接
    {
        return; //退出函数
    }

    memset(MQTT_Send_Buffer, 0, sizeof(MQTT_Send_Buffer)); //清空发送缓冲区
    MQTT_Send_Buffer[0] = 0x30; //MQTT发布请求标志
    MQTT_Send_Buffer[1] = strlen(PUB_TOPIC)+strlen(payload)+2; //MQTT报文固定头部长度+主题长度+消息长度
    MQTT_Send_Buffer[2] = 0x00; //MQTT主题长度高位
    MQTT_Send_Buffer[3] = strlen(PUB_TOPIC); //MQTT主题长度低位
    memcpy(&MQTT_Send_Buffer[4], PUB_TOPIC, strlen(PUB_TOPIC)); //MQTT主题
    MQTT_Send_Buffer[4+strlen(PUB_TOPIC)] = 0x00; //MQTT报文标识符高位
    MQTT_Send_Buffer[5+strlen(PUB_TOPIC)] = 0x01; //MQTT报文标识符低位
    memcpy(&MQTT_Send_Buffer[6+strlen(PUB_TOPIC)], payload, strlen(payload)); //MQTT消息

    MQTT_Send_Len = 6+strlen(PUB_TOPIC)+strlen(payload); //MQTT发布请求长度

    UART_SendByte(0x1A); //发送AT指令
    UART_SendString("AT+MQTTPUB="); //发布主题
    UART_SendByte(MQTT_Send_Len/256);
    UART_SendByte(MQTT_Send_Len%256);
    UART_SendByte(0x01); //MQTT发布请求标志
    UART_SendString("\r\n");
    for(uint i=0; i<MQTT_Send_Len; i++)
    {
        UART_SendByte(MQTT_Send_Buffer[i]); //发送MQTT发布请求
    }

    delay_ms(1000);
}

//串口中断函数
void UART_ISR() interrupt 4
{
    if(RI) //接收到一个字节
    {
        RI = 0; //清除接收标志
        RX_Buffer[RX_Count++] = SBUF; //保存接收到的字节
        if(RX_Count == sizeof(RX_Buffer)) //如果接收缓冲区已满
        {
            RX_Count = 0; //清空计数器
        }
        if(SBUF == '\n') //如果接收到回车符
        {
            RX_Flag = 1; //设置接收完成标志
        }
    }
}

//延时函数
void delay_ms(uint ms)
{
    uint i, j;
    for(i=0; i<ms; i++)
    {
        for(j=0; j<110; j++);
    }
}

注意，以上代码仅为示例代码，需要根据自己的情况进行修改。在使用该代码之前，需要先在阿里云控制台创建设备并获取设备三元组，然后将相应的信息填写到代码中。同时，还需要在阿里云控制台配置相应的规则引擎和数据流转等功能，才能实现设备与云端的数据通信。