#include "mqtt.h"
u8 *mqtt_rxbuf;u8 *mqtt_txbuf;u16 mqtt_rxlen;u16 mqtt_txlen;u8 _mqtt_txbuf[256];//发送数据缓存区u8 _mqtt_rxbuf[256];//接收数据缓存区
typedef enum{ //名字 值 报文流动方向 描述 M_RESERVED1 =0 , // 禁止 保留 M_CONNECT , // 客户端到服务端 客户端请求连接服务端 M_CONNACK , // 服务端到客户端 连接报文确认 M_PUBLISH , // 两个方向都允许 发布消息 M_PUBACK , // 两个方向都允许 QoS 1消息发布收到确认 M_PUBREC , // 两个方向都允许 发布收到（保证交付第一步） M_PUBREL , // 两个方向都允许 发布释放（保证交付第二步） M_PUBCOMP , // 两个方向都允许 QoS 2消息发布完成（保证交互第三步） M_SUBSCRIBE , // 客户端到服务端 客户端订阅请求 M_SUBACK , // 服务端到客户端 订阅请求报文确认 M_UNSUBSCRIBE , // 客户端到服务端 客户端取消订阅请求 M_UNSUBACK , // 服务端到客户端 取消订阅报文确认 M_PINGREQ , // 客户端到服务端 心跳请求 M_PINGRESP , // 服务端到客户端 心跳响应 M_DISCONNECT , // 客户端到服务端 客户端断开连接 M_RESERVED2 , // 禁止 保留}_typdef_mqtt_message;
//连接成功服务器回应 20 02 00 00//客户端主动断开连接 e0 00const u8 parket_connetAck[] = {0x20,0x02,0x00,0x00};const u8 parket_disconnet[] = {0xe0,0x00};const u8 parket_heart[] = {0xc0,0x00};const u8 parket_heart_reply[] = {0xc0,0x00};const u8 parket_subAck[] = {0x90,0x03};
void MQTT_Init(void){ //缓冲区赋值 mqtt_rxbuf = _mqtt_rxbuf; mqtt_rxlen = sizeof(_mqtt_rxbuf); mqtt_txbuf = _mqtt_txbuf; mqtt_txlen = sizeof(_mqtt_txbuf); memset(mqtt_rxbuf,0,mqtt_rxlen); memset(mqtt_txbuf,0,mqtt_txlen); //无条件先主动断开 MQTT_Disconnect(); delay_ms(100); MQTT_Disconnect(); delay_ms(100);}
/*函数功能: 登录服务器函数返回值: 0表示成功 1表示失败*/u8 MQTT_Connect(char *ClientID,char *Username,char *Password){ u8 i,j; int ClientIDLen = strlen(ClientID); int UsernameLen = strlen(Username); int PasswordLen = strlen(Password); int DataLen; mqtt_txlen=0; //可变报头+Payload 每个字段包含两个字节的长度标识 DataLen = 10 + (ClientIDLen+2) + (UsernameLen+2) + (PasswordLen+2); //固定报头 //控制报文类型 mqtt_txbuf[mqtt_txlen++] = 0x10; //MQTT Message Type CONNECT //剩余长度(不包括固定头部) do { u8 encodedByte = DataLen % 128; DataLen = DataLen / 128; // if there are more data to encode, set the top bit of this byte if ( DataLen > 0 ) encodedByte = encodedByte | 128; mqtt_txbuf[mqtt_txlen++] = encodedByte; }while ( DataLen > 0 ); //可变报头 //协议名 mqtt_txbuf[mqtt_txlen++] = 0; // Protocol Name Length MSB mqtt_txbuf[mqtt_txlen++] = 4; // Protocol Name Length LSB mqtt_txbuf[mqtt_txlen++] = 'M'; // ASCII Code for M mqtt_txbuf[mqtt_txlen++] = 'Q'; // ASCII Code for Q mqtt_txbuf[mqtt_txlen++] = 'T'; // ASCII Code for T mqtt_txbuf[mqtt_txlen++] = 'T'; // ASCII Code for T //协议级别 mqtt_txbuf[mqtt_txlen++] = 4; // MQTT Protocol version = 4 对于 3.1.1 版协议，协议级别字段的值是 4(0x04) //连接标志 mqtt_txbuf[mqtt_txlen++] = 0xc2; // conn flags mqtt_txbuf[mqtt_txlen++] = 0; // Keep-alive Time Length MSB mqtt_txbuf[mqtt_txlen++] = 100; // Keep-alive Time Length LSB 100S心跳包 保活时间 mqtt_txbuf[mqtt_txlen++] = BYTE1(ClientIDLen);// Client ID length MSB mqtt_txbuf[mqtt_txlen++] = BYTE0(ClientIDLen);// Client ID length LSB memcpy(&mqtt_txbuf[mqtt_txlen],ClientID,ClientIDLen); mqtt_txlen += ClientIDLen; if(UsernameLen > 0) { mqtt_txbuf[mqtt_txlen++] = BYTE1(UsernameLen); //username length MSB mqtt_txbuf[mqtt_txlen++] = BYTE0(UsernameLen); //username length LSB memcpy(&mqtt_txbuf[mqtt_txlen],Username,UsernameLen); mqtt_txlen += UsernameLen; } if(PasswordLen > 0) { mqtt_txbuf[mqtt_txlen++] = BYTE1(PasswordLen); //password length MSB mqtt_txbuf[mqtt_txlen++] = BYTE0(PasswordLen); //password length LSB memcpy(&mqtt_txbuf[mqtt_txlen],Password,PasswordLen); mqtt_txlen += PasswordLen; } memset(mqtt_rxbuf,0,mqtt_rxlen); MQTT_SendBuf(mqtt_txbuf,mqtt_txlen); for(j=0;j<10;j++) { delay_ms(50); if(USART3_RX_FLAG) { memcpy((char *)mqtt_rxbuf,USART3_RX_BUFFER,USART3_RX_CNT); //memcpy for(i=0;i<USART3_RX_CNT;i++)USART1_Printf("%#x ",USART3_RX_BUFFER[i]); USART3_RX_FLAG=0; USART3_RX_CNT=0; } //CONNECT if(mqtt_rxbuf[0]==parket_connetAck[0] && mqtt_rxbuf[1]==parket_connetAck[1]) //连接成功 { return 0;//连接成功 } } return 1;}
/*函数功能: MQTT订阅/取消订阅数据打包函数函数参数: topic 主题 qos 消息等级 0:最多分发一次 1: 至少分发一次 2: 仅分发一次 whether 订阅/取消订阅请求包 (1表示订阅,0表示取消订阅)返回值: 0表示成功 1表示失败*/u8 MQTT_SubscribeTopic(char *topic,u8 qos,u8 whether){ u8 i,j; mqtt_txlen=0; int topiclen = strlen(topic); int DataLen = 2 + (topiclen+2) + (whether?1:0);//可变报头的长度（2字节）加上有效载荷的长度 //固定报头 //控制报文类型 if(whether)mqtt_txbuf[mqtt_txlen++] = 0x82; //消息类型和标志订阅 else mqtt_txbuf[mqtt_txlen++] = 0xA2; //取消订阅
//剩余长度 do { u8 encodedByte = DataLen % 128; DataLen = DataLen / 128; // if there are more data to encode, set the top bit of this byte if ( DataLen > 0 ) encodedByte = encodedByte | 128; mqtt_txbuf[mqtt_txlen++] = encodedByte; }while ( DataLen > 0 ); //可变报头 mqtt_txbuf[mqtt_txlen++] = 0; //消息标识符 MSB mqtt_txbuf[mqtt_txlen++] = 0x0A; //消息标识符 LSB //有效载荷 mqtt_txbuf[mqtt_txlen++] = BYTE1(topiclen);//主题长度 MSB mqtt_txbuf[mqtt_txlen++] = BYTE0(topiclen);//主题长度 LSB memcpy(&mqtt_txbuf[mqtt_txlen],topic,topiclen); mqtt_txlen += topiclen; if(whether) { mqtt_txbuf[mqtt_txlen++] = qos;//QoS级别 } for(i=0;i<10;i++) { memset(mqtt_rxbuf,0,mqtt_rxlen); MQTT_SendBuf(mqtt_txbuf,mqtt_txlen); for(j=0;j<10;j++) { delay_ms(50); if(USART3_RX_FLAG) { memcpy((char *)mqtt_rxbuf,(char*)USART3_RX_BUFFER,USART3_RX_CNT); USART3_RX_FLAG=0; USART3_RX_CNT=0; } if(mqtt_rxbuf[0]==parket_subAck[0] && mqtt_rxbuf[1]==parket_subAck[1]) //订阅成功 { return 0;//订阅成功 } } } return 1; //失败}
//MQTT发布数据打包函数//topic 主题 //message 消息//qos 消息等级 u8 MQTT_PublishData(char *topic, char *message, u8 qos){ int topicLength = strlen(topic); int messageLength = strlen(message); static u16 id=0; int DataLen; mqtt_txlen=0; //有效载荷的长度这样计算：用固定报头中的剩余长度字段的值减去可变报头的长度 //QOS为0时没有标识符 //数据长度 主题名 报文标识符 有效载荷 if(qos) DataLen = (2+topicLength) + 2 + messageLength; else DataLen = (2+topicLength) + messageLength;
//固定报头 //控制报文类型 mqtt_txbuf[mqtt_txlen++] = 0x30; // MQTT Message Type PUBLISH
//剩余长度 do { u8 encodedByte = DataLen % 128; DataLen = DataLen / 128; // if there are more data to encode, set the top bit of this byte if ( DataLen > 0 ) encodedByte = encodedByte | 128; mqtt_txbuf[mqtt_txlen++] = encodedByte; }while ( DataLen > 0 ); mqtt_txbuf[mqtt_txlen++] = BYTE1(topicLength);//主题长度MSB mqtt_txbuf[mqtt_txlen++] = BYTE0(topicLength);//主题长度LSB memcpy(&mqtt_txbuf[mqtt_txlen],topic,topicLength);//拷贝主题 mqtt_txlen += topicLength; //报文标识符 if(qos) { mqtt_txbuf[mqtt_txlen++] = BYTE1(id); mqtt_txbuf[mqtt_txlen++] = BYTE0(id); id++; } memcpy(&mqtt_txbuf[mqtt_txlen],message,messageLength); mqtt_txlen += messageLength; MQTT_SendBuf(mqtt_txbuf,mqtt_txlen); return mqtt_txlen;}
void MQTT_SentHeart(void){ MQTT_SendBuf((u8 *)parket_heart,sizeof(parket_heart));}
void MQTT_Disconnect(void){ MQTT_SendBuf((u8 *)parket_disconnet,sizeof(parket_disconnet));}
void MQTT_SendBuf(u8 *buf,u16 len){ USARTx_DataSend(USART3,buf,len);}
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