Bc35 NB module at instruction development summary

One .BC35 NB Module introduction

  BC35-G It's a high performance 、 Low power consumption NB-IoT modular , Support the six frequency bands listed in the following table . adopt NB-IoT Radio communication protocol （3GPP Rel. 14）,BC35-G The module can establish communication with the infrastructure of the network operator .

Power supply :
VBAT Supply voltage range ：3.1V~4.2V
Typical supply voltage ：3.6V

Transmitting power ：
23dBm±2dB

A serial port ：
Main serial port ： be used for AT Command communication and data transmission , The baud rate supported is 4800bps、9600bps（ Default ）、57600bps、115200bps、230400bps and 460800bps, For firmware upgrade , The baud rate supported is 115200bps and 921600bps
Debug serial port ： For software debugging , Only baud rate is supported 921600bps

Network protocol characteristics ：
Support IPv4/IPv6/UDP/CoAP/LwM2M/Non-IP/DTLS/TCP/MQTT agreement

Antenna interface :
50Ω Characteristic impedance

Two .TCP Data transmission process

1. The module is powered on ----->2. Module networking ----->3. establish TCP Connect ----->4.TCP send data ----->5. Wait for the data to be returned and processed ----->6. The module is powered off .

Detailed procedure flow ：

 Related support functions ：
// A serial port 1,printf  function 
// Ensure that no more than... Data is sent at one time USART1_MAX_SEND_LEN byte 
void nb_printf(char* fmt,...)  
{
      
 u16 i;
 va_list ap;
 va_start(ap,fmt);
 vsprintf((char*)USART1_TX_BUF,fmt,ap);
 va_end(ap);
 i=strlen((const char*)USART1_TX_BUF);// The length of the data sent this time 

    /* Use serial port register operation to send data */
// for(j=0;j<i;j++)// Loop data 
// {
    
// while((USART1->ISR&0X40)==0); // Cycle to send , Until it's sent  
// USART1->TDR=USART1_TX_BUF[j]; 
// }
    /* Serial port is adopted HAL Library functions send data */
// HAL_UART_Transmit(&huart1, (uint8_t*)USART1_TX_BUF,i, 1000); // Send received data 
// while(__HAL_UART_GET_FLAG(&huart1, UART_FLAG_TC) != SET); // Wait for the end of sending 

    /* use DMA Send data by */
    HAL_USART1_DMA_TX(&USART1TxDMA_Handler,DMA_FLAG_TC2,&huart1,USART1_TX_BUF,i);// Use DMA send data 
    memset(USART1_TX_BUF,0,sizeof(USART1_TX_BUF));// Empty cache 
}
//NB_MODULE After sending the order , Detect the received response 
//str: Expected response results 
// Return value :0, Did not get the expected response results 
//  other , Where to expect the response result (str The location of )
u8* nb_send_check_cmd(u8 *str)
{
    
 char *strx=0;
    USART1_RX_BUF[USART1_RX_COUNT]=0;// Add Terminator 
    strx=strstr((const char*)USART1_RX_BUF,(const char*)str);
 return (u8*)strx;
}
// towards NB_MODULE Send the specified data 
//data: Data sent ( There is no need to add carriage return )
//ack: Expected response results , If it is empty , It means that there is no need to wait for a response 
//waittime: Waiting time ( Company :100ms)
// Return value :0, Send successfully ( Got the expected response results )
// 1, fail in send 
u8 nb_send_cmd(u8 *data,u8 *ack,u16 waittime)
{
    
    waittime=waittime*100;
    nb_printf("%s\r\n",data);           // What needs to be sent is the command 
 if(ack&&waittime)                   // Need to wait for a response 
 {
    
        while(--waittime)                  // Wait for the countdown 
        {
    
            delay_ms(1);
            if(USART1_IDLE_FLAG)             // Received the expected response result 
            {
    
                if(nb_send_check_cmd(ack))
                {
    
                   //printf("%s ack: %s\r\n",data,(u8*)ack);
                   Feed_Dog();                          // feed a dog 
                   memset(USART1_RX_BUF,0,sizeof(USART1_RX_BUF));// Empty USART1 cache 
                   USART1_IDLE_FLAG=0;
                   USART1_RX_COUNT=0;        // A serial port 1 Accept data reset 
                   return 0;                 //ack correct , return 1
                }
                memset(USART1_RX_BUF,0,sizeof(USART1_RX_BUF));// Empty USART1 cache 
                USART1_IDLE_FLAG=0;
                USART1_RX_COUNT=0;// A serial port 1 Accept data reset 
            } 
        }
 }
 return 1;                                //ack error , return 0
}
// towards NB_MODULE Send the specified data , And read the return parameter value 
//data: Data sent ( There is no need to add carriage return )
//ack: Expected response results , If it is empty , It means that there is no need to wait for a response 
//waittime: Waiting time ( Company :100ms)
// Return value :0, Send successfully ( Got the expected response results )
// 1, fail in send 
u8 nb_send_cmd_return(u8 *data,u8 *ack,u16 waittime,u8 *parameter)
{
    
    nb_printf("%s\r\n",data);           // What needs to be sent is the command 
 if(ack&&waittime)                   // Need to wait for a response 
 {
    
        while(--waittime)                  // Wait for the countdown 
        {
    
            delay_ms(100);
            if(USART1_IDLE_FLAG)             // Received the expected response result 
            {
    
                if(nb_send_check_cmd(ack))
                {
    
                   *parameter=USART1_RX_BUF[2];
                   printf("%s ack: %s\r\n",data,(u8*)ack);
                   Feed_Dog();                          // feed a dog 
                   memset(USART1_RX_BUF,0,sizeof(USART1_RX_BUF));// Empty USART1 cache 
                   USART1_IDLE_FLAG=0;
                   USART1_RX_COUNT=0;        // A serial port 1 Accept data reset 
                   return 0;                 //ack correct , return 1
                }
                memset(USART1_RX_BUF,0,sizeof(USART1_RX_BUF));// Empty USART1 cache 
                USART1_IDLE_FLAG=0;
                USART1_RX_COUNT=0;// A serial port 1 Accept data reset 
            } 
        }
 }
 return 1;                                //ack error , return 0
}

2. Module networking 
/** * @brief NB Module networking  *  Reference manual ：p160  Manual network connection  * * @param void * * @return 0: Successful connection  * 1: The connection fails  */
u8 NB_Connect_To_Internet(void)
{
    
    u8 i=0;
    for(i=0;i<3;i++)
    if(nb_send_cmd((u8 *)"AT+NRB",(u8 *)"REBOOT_CAUSE_APPLICATION_AT",100)==0)break;
    if(i==3)
    {
    
        printf(" Module restart failed ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Module restart succeeded ...\r\n\r\n");
    
    for(i=0;i<3;i++)
    if(nb_send_cmd((u8 *)"AT+NBAND=5",(u8 *)"OK",10)==0)break;
    if(i==3)
    {
    
        printf(" Failed to set frequency band ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Set frequency band successfully ...\r\n\r\n");

    for(i=0;i<3;i++)
    if(nb_send_cmd((u8 *)"AT+CFUN=1",(u8 *)"OK",40)==0)break;
    if(i==3)
    {
    
        printf(" Failed to set the maximum function mode ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Set the maximum function mode successfully ...\r\n\r\n");
    i=0;
    
    for(i=0;i<3;i++)
    if(nb_send_cmd((u8 *)"AT+CEDRXS=0,5",(u8 *)"OK",10)==0)break;
    if(i==3)
    {
    
        printf(" Close module eDRX Function failed ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Close module eDRX Function success ...\r\n\r\n");
    
    for(i=0;i<3;i++)
    if(nb_send_cmd((u8 *)"AT+CGATT=1",(u8 *)"OK",20)==0)break;
    if(i==3)
    {
    
        printf(" Failed to attach the network ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Successfully attached to the network ...\r\n\r\n");
    
    for(i=0;i<10;i++)
    if(nb_send_cmd((u8 *)"AT+CGATT?",(u8 *)"+CGATT:1",20)==0)break;
    if(i==10)
    {
    
        printf(" Network connection failed ...\r\n\r\n");
        return 1;
    }
    else 
        printf(" Network connection successful ...\r\n\r\n");
        return 0;
}
3. establish TCP Connect 
/** * @brief  establish TCP Connect  * * @param ip： Need to connect ip Address  * port： Port to be connected  * socket： After the connection is successful, the created socket value  * * @return 0: Send successfully  * 1: fail in send  */
u8 NB_TCP_Connect(const u8* ip,const u8* port,u8* socket)
{
    
    u8 i=0;
    u8 p[50];
    for(i=0;i<3;i++)
    if(nb_send_cmd_return((u8 *)"AT+NSOCR=STREAM,6,0,1",(u8 *)"OK",100,socket)==0)break;    
    if(i<3)printf(" establish socket success ...\r\n\r\n");
    else 
    {
    
        printf(" establish socket Failure ...\r\n\r\n");
        return 1;
    }
    *socket=*socket-48;
    printf("tcp_socket=%d\r\n",*socket);
    sprintf((char*)p,"AT+NSOCO=%d,%s,%s",*socket,ip,port);
    for(i=0;i<3;i++)
    if(nb_send_cmd((u8 *)p,(u8 *)"OK",100))break;  
    if(i<3)printf("TCP Successful connection ...\r\n\r\n");
    else 
    {
    
        printf("TCP The connection fails ...\r\n\r\n");
        return 1;
    }
    return 0;
}
4.TCP send data 
/** * @brief TCP send data  * * @param socket: Socket size  * data： Data sent  * len： Length of data sent  * * @return 0: Send successfully  * 1: fail in send  */
u8 tx_buffer[2000]={
    0};           // Define the final send data buffer 
u8 p[2000];                       // Encapsulated into the final frame format to be sent 
u8 NB_TCP_Send_Data(u8 socket,u8* data,u16 len)
{
    
    u8 i=0;
    HexArrayToString(data,(char*)USART1_TX_BUF,len);          // First, convert the original data into a string 
    HexArrayToString(USART1_TX_BUF,(char*)tx_buffer,2*len);   // Let's talk about string conversion ASCII code 
    sprintf((char*)p,"AT+NSOSD=%d,%d,%s,%s,%s",socket,2*len,(char*)tx_buffer,"0x100","101");
    memset(USART1_TX_BUF,0,sizeof(USART1_TX_BUF));// Empty cache , Because nb_send_cmd() You also need to use USART1_TX_BUF, So it needs to be emptied 
    memset(tx_buffer,0,sizeof(tx_buffer));        // Empty cache , Because nb_send_cmd() You also need to use USART1_TX_BUF, So it needs to be emptied 
    for(i=0;i<3;i++)
    if(nb_send_cmd((u8 *)p,(u8 *)"101,1",50)==0)break;    
    memset(p,0,sizeof(p));// Empty cache 
    if(i<3)
    {
    
        printf("TCP Data sent successfully , And the confirmation is received by the server ...\r\n\r\n");
        return 0;
    }
    else 
    {
    
        printf("TCP Failed to send data ...\r\n\r\n");
        return 1;
    }
}
5. Wait for the data to be returned and processed （ Partial procedure ）
       while(1)                        // Wait for the countdown of cloud data 
       {
    
          delay_ms(5);                            // Time delay 5ms Determine if data is received 
          if(USART1_IDLE_FLAG)                     // A serial port 1 Receiving data is over , And NB Module communication 
          {
    
               /* Determine whether there is data from the server */
               str1=nb_send_check_cmd((u8 *)"+NSONMI:");// Judge whether the received data is +NSONMI:
               if(str1)                                 // Make sure you receive +NSONMI:
               {
         
                   receive_socket=*(str1+8)-48;                                                  // Get the current socket Number 
                   if(USART1_RX_COUNT-14==1)receive_num=*(str1+10)-48;
                   else if(USART1_RX_COUNT-14==2)receive_num=(*(str1+10)-48)*10+*(str1+11)-48;   // Get the number of bytes currently received 
                   sprintf((char*)q,"%d,%s,%s,%d",receive_socket,IP_address,portnum,receive_num);// Form a package 
                   receive_data_flag=1;                 // Received data flag position bit 
               }
               
               /* Judge whether the data from the server is received */
               str2=nb_send_check_cmd((u8*)q);          // Judge whether the received data is +NSONMI:
               if(str2)                                 // Confirm that the data is received 
               {
        
                    HexStrToByte(str2+strlen(q)+1,Receive_Buffer,2*receive_num);    // Put the characters as HEX And exist Receive_Buffer in , To be processed 
                    read_data_flag=1;             // Data processing flag position bit 
               }
                 memset(USART1_RX_BUF,0,sizeof(USART1_RX_BUF));// Empty cache 
                 USART1_RX_COUNT=0;                  // Clear the number of bytes accepted 
                 USART1_IDLE_FLAG=0;                 // Idle interrupt flag reset 
           }
           if(receive_data_flag)                     // Confirm that the module receives data from the server 
           {
    
               sprintf((char*)p,"AT+NSORF=%d,%d",receive_socket,200);
               nb_printf("%s\r\n",p);                // Send and receive data instructions 
               receive_data_flag=0;                  // Received data flag bit reset 
           }
           /* Data processing is needed */
           if(read_data_flag)                        // Confirm that data processing is required 
           {
    
	       for(i=0;i<receive_num;i++)
               printf("%x ",Receive_Buffer[i]);     
               printf("\r\n");
               waittime=4000;                                        // The timing time is resumed after receiving data once 
               break;
           }
}

3、 ... and .UDP Data transmission process

1. The module is powered on ----->2. Module networking ----->3. establish UDP Connect ----->4.UDP send data ----->5. Wait for the data to be returned and processed ----->6. The module is powered off .

Detailed procedure flow ：

 Related support functions ：
 Same as above TCP Agreement 

2. Module networking 
 Same as above TCP Agreement 

3. establish UDP Connect 
/** * @brief  establish UDP Connect  * * @param ip： Need to connect ip Address  * port： Port to be connected  * socket： After the connection is successful, the created socket value  * * @return 0: Send successfully  * 1: fail in send  */
u8 NB_UDP_Creat_socket(u8* socket)
{
    
    u8 i=0;
    for(i=0;i<3;i++)
    if(nb_send_cmd_return((u8 *)"AT+NSOCR=DGRAM,17,0,1",(u8 *)"OK",100,socket)==0)break;  
    if(i<3)
    {
    
        printf(" establish socket success ...\r\n\r\n");
        *socket=*socket-48;
        printf("udp_socket=%d\r\n",*socket);
        return 0;
    }
    else printf(" establish socket Failure ...\r\n\r\n");
    return 1;
}
4.UDP send data 
/** * @brief UDP send data  * * @param socket: Socket size  * data： Data sent  * len： Length of data sent  * * @return 0: Send successfully  * 1: fail in send  */               
u8 NB_UDP_Send_Data(u8 socket,const u8* ip,const u8* port,u8* data,u16 len)
{
    
    u16 i=0;
    HexArrayToString(data,(char*)USART1_TX_BUF,len);          // First, convert the original data into a string 
    HexArrayToString(USART1_TX_BUF,(char*)tx_buffer,2*len);   // Let's talk about string conversion ASCII code 
    sprintf((char*)p,"AT+NSOST=%d,%s,%s,%d,%s,%d",socket,ip,port,2*len,(char*)tx_buffer,100);
    memset(USART1_TX_BUF,0,sizeof(USART1_TX_BUF));// Empty cache , Because nb_send_cmd() You also need to use USART1_TX_BUF, So it needs to be emptied 
    memset(tx_buffer,0,sizeof(tx_buffer));        // Empty cache , Because nb_send_cmd() You also need to use USART1_TX_BUF, So it needs to be emptied 
    for(i=0;i<3;i++)
    if(nb_send_cmd((u8 *)p,(u8 *)"100,1",100)==0)break;    
    memset(p,0,sizeof(p));// Empty cache 
    if(i<3)
    {
    
       printf("UDP Data sent successfully ...\r\n\r\n");
       return 0;
    }
    else 
    {
    
        printf("UDP Failed to send data ...\r\n\r\n");
        return 1;
    }
}
5. Wait for the data to be returned and processed 
 Same as above TCP Agreement