stm32搭建mqtt_基于STM32实现MQTT

#include "mqtt.h"

unsigned char GetDataFixedHead(unsigned char MesType,unsigned char DupFlag,unsigned char QosLevel,unsigned char Retain)

{

unsigned char dat = 0;

dat = (MesType & 0x0f) << 4;

dat |= (DupFlag & 0x01) << 3;

dat |= (QosLevel & 0x03) << 1;

dat |= (Retain & 0x01);

return dat;

}

void GetDataConnet(unsigned char *buff)//获取连接的数据包正确连接返回20 02 00 00

{

unsigned int i,len,lennum = 0;

unsigned char *msg;

buff[0] = GetDataFixedHead(MQTT_TypeCONNECT,0,0,0);

buff[2] = 0x00;

buff[3] = 0x04;

buff[4] = 'M';

buff[5] = 'Q';

buff[6] = 'T';

buff[7] = 'T';

buff[8] = 0x04;//协议级别 Protocol Level

buff[9] = 0 | (MQTT_StaCleanSession << 1) | (MQTT_StaWillFlag << 1)

| (MQTT_StaWillQoS << 3) | (MQTT_StaWillRetain << 5)

| (MQTT_StaPasswordFlag << 6) |(MQTT_StaUserNameFlag << 7);//连接标志

buff[10] = MQTT_KeepAlive >> 8;

buff[11] = MQTT_KeepAlive;

len = strlen(MQTT_ClientIdentifier);

buff[12] = len >> 8;

buff[13] = len;

msg = MQTT_ClientIdentifier;

for(i = 0;i

{

buff[14+i] = msg[i];

}

lennum += len;

if(MQTT_StaWillFlag)

{

len = strlen(MQTT_WillTopic);

buff[13 + lennum + 1] = len >> 8;

buff[13 + lennum + 2] = len;

lennum += 2;

msg = MQTT_WillTopic;

for(i = 0;i

{

buff[14+lennum+i] = msg[i];

}

lennum += len;

len = strlen(MQTT_WillMessage);

buff[12] = len >> 8;

buff[13] = len;

lennum += 2;

msg = MQTT_WillMessage;

for(i = 0;i

{

buff[14+lennum+i] = msg[i];

}

lennum += len;

}

if(MQTT_StaUserNameFlag)

{

len = strlen(MQTT_UserName);

buff[13 + lennum + 1] = len >> 8;

buff[13 + lennum + 2] = len;

lennum += 2;

msg = MQTT_UserName;

for(i = 0;i

{

buff[14+lennum+i] = msg[i];

}

lennum += len;

}

if(MQTT_StaPasswordFlag)

{

len = strlen(MQTT_Password);

buff[13 + lennum + 1] = len >> 8;

buff[13 + lennum + 2] = len;

lennum += 2;

msg = MQTT_Password;

for(i = 0;i

{

buff[14+lennum+i] = msg[i];

}

lennum += len;

}

buff[1] = 13 + lennum - 1;

}

void GetDataDisConnet(unsigned char *buff)//获取断开连接的数据包

{

buff[0] = 0xe0;

buff[1] = 0;

}

void GetDataPINGREQ(unsigned char *buff)//心跳请求的数据包成功返回d0 00

{

buff[0] = 0xc0;

buff[1] = 0;

}

/*

成功返回90 0x 00 Num RequestedQoS

*/

void GetDataSUBSCRIBE(unsigned char *buff,const char *dat,unsigned int Num,unsigned char RequestedQoS)//订阅主题的数据包 Num:主题序号 RequestedQoS:服务质量要求0,1或2

{

unsigned int i,len = 0,lennum = 0;

buff[0] = 0x82;

len = strlen(dat);

buff[2] = Num>>8;

buff[3] = Num;

buff[4] = len>>8;

buff[5] = len;

for(i = 0;i

{

buff[6+i] = dat[i];

}

lennum = len;

buff[6 + lennum ] = RequestedQoS;

buff[1] = lennum + 5;

}

void GetDataPUBLISH(unsigned char *buff,unsigned char dup, unsigned char qos,unsigned char retain,const char *topic ,const char *msg)//获取发布消息的数据包

{

unsigned int i,len=0,lennum=0;

buff[0] = GetDataFixedHead(MQTT_TypePUBLISH,dup,qos,retain);

len = strlen(topic);

buff[2] = len>>8;

buff[3] = len;

for(i = 0;i

{

buff[4+i] = topic[i];

}

lennum = len;

len = strlen(msg);

for(i = 0;i

{

buff[4+i+lennum] = msg[i];

}

lennum += len;

buff[1] = lennum + 2;

}