Ec20/ec25 4G module at instruction development summary

One .EC25/20 4G Module introduction

  EC25 It is a series of with diversity receiving function LTE-FDD/LTE-TDD/WCDMA/GSM Wireless communication module .
1. Power supply ：
VBAT Supply voltage range ：3.3V~4.3V
Typical supply voltage ：3.8V
2. Network protocol characteristics ：
Support TCP/UDP/PPP/FTP/FTPS/HTTP/HTTPS/NTP/PING/
QMI/NITZ/SMTP/SSL/MQTT/CMUX/SMTPS/MMS*/FILE* agreement
Support PAP (Password Authentication Protocol) and CHAP (Challenge Handshake Authentication Protocol) agreement .
3. Main serial port ：
 be used for AT Command transmission and data transmission .
 The maximum baud rate is 921600bps, The default is 115200bps（ It can be done by AT Instruction configuration modifies baud rate ）.
 Support RTS and CTS Hardware flow control .
4. Switch on and reset ：
Turn it on ： You can pull it down PWRKEY At least 500ms Turn on the module .
To turn it off ： adopt PWRKEY Pin control module shutdown .
    send out AT+QPOWD Command shutdown .
Reset ：RESET_N Pin can be used for module reset . Pull it down RESET_N Pin 150ms~460ms After that, the module can be reset .

Two .AT Summary of instructions

1. Universal AT Instructions

 AT： Test instruction , return OK.
 ATE0： Close back display , return OK.
 AT+CCLK?： Get network time , See the reference manual for the return format .（ Note that the time returned here is the local time of the base station , You may need to convert it to Beijing time ）
 AT+QCCID： obtain SIM Card number . See the reference manual for the return format .
 AT+CSQ： Get the signal strength , return 0-31, return 99 For no signal .
 AT+QPOWD： Module shutdown .

2. establish TCP/UDP Connection correlation AT Instructions

 AT+CPIN?： Judge SIM Whether the state is normal , Normal return READY.
 AT+CREG?： Check whether the network registration is successful , Successfully returns OK.
 AT+QICSGP=1,1,“MOBILE”,"","",1： To configure TCP/IP Environmental Science , Successfully returns OK.
 AT+QIACT=1： Activate TCP/IP Environmental Science , Successfully returns OK.
 AT+QIOPEN=1,0,“TCP”,“ip”,port,0,2： establish TCP Connect （ Passthrough mode ）, among ip and port Replace with the actual network value to be connected . Connection successful return CONNECT.（ So far, we have established TCP Connect , Data can be transmitted directly ）
 AT+QIOPEN=1,2,“UDP SERVICE”,“127.0.0.1”,0,3030,1： establish UDP The server . Successfully returns OK.（ So far, it has not been established UDP Connect , You can't send data ）
 AT+QISEND=2,len,“ip”,port ：UDP Prepare to send data instructions , The length of data sent here len, Purpose ip Address and port number port It should be given according to the actual , received ">" Then send the data , Sent successfully received SEND OK.
 +++ ： sign out TCP Passthrough mode （ Exit transparent transmission after sending data ）.
 AT+QICLOSE=0/2 ： Close the connection （ Here 0/2 Is the connection number , By the previous AT+QIOPEN Command on ）.

3、 ... and .TCP Data transmission process

1.POWERKEY Turn it on ----->2. Module networking ----->3. establish TCP Connect ----->4.TCP send data ----->5. Wait for the data to be returned and processed ----->6. Module shutdown （POWERKEY or AT Instructions ）.
Detailed procedure ：

 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 fg_printf(char* fmt,...)  
{
      
	u16 i=0;
	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 
}

//4G_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* fg_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 4G_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 fg_send_cmd(u8 *data,u8 *ack,u16 waittime)
{
    
    waittime=waittime*100;
    fg_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(fg_send_check_cmd(ack))
                {
    
                   printf("%s ack: %s\r\n",data,(u8*)ack);
				   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
}

//1.4G Turn it on 
void FourG_Power_On(void)
{
    
    POWERKEY(1);
    delay_ms(600);
    POWERKEY(0);
}
//2. Module networking 
/** * @brief 4G Module networking  * * @param void * * @return 0: Successful connection  * 1: The connection fails  */
u8 FourG_Connect_To_Internet(void)
{
    
    u8 i=0;
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT",(u8 *)"OK",100)==0)break;
    if(i==3)
    {
    
        printf(" Module status is abnormal ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" The module status is normal ...\r\n\r\n");
    
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"ATE0",(u8 *)"OK",100)==0)break;
    if(i==3)
    {
    
        printf(" Failed to close echo ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Closing echo succeeded ...\r\n\r\n");
    
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT+CPIN?",(u8 *)"READY",10)==0)break;
    if(i==3)
    {
    
        printf("SIM Card status is abnormal ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf("SIM The card status is normal ...\r\n\r\n");

    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT+CREG?",(u8 *)"OK",10)==0)break;
    if(i==3)
    {
    
        printf("CS Network registration failed ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf("CS Network registration successful ...\r\n\r\n");
    return 0;
}
//3. establish TCP Connect 
/** * @brief 4G Module building TCP Connect  * * @param ip： Need to connect ip Address  * port： Port to be connected  * * @return 0: establish TCP Successful connection  * 1: establish TCP The connection fails  */
u8 FG_TCP_Connect(const u8* ip,const u8* port)
{
    
    u8 i=0;
    char p[50]={
    0};
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT+QICSGP=1,1,\"MOBILE\",\"\",\"\",1",(u8 *)"OK",10)==0)break;
    if(i==3)
    {
    
        printf(" To configure TCP/IP Environment failure ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" To configure TCP/IP Environment success ...\r\n\r\n");
    
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT+QIACT=1",(u8 *)"OK",10)==0)break;
    if(i==3)
    {
    
        printf(" Activate TCP/IP Environment failure ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Activate TCP/IP Environment success ...\r\n\r\n");
    
    sprintf((char*)p,"AT+QIOPEN=1,0,\"TCP\",\"%s\",%s,0,2",ip,port);
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)p,(u8 *)"CONNECT",10)==0)break;
    if(i==3)
    {
    
        printf(" Set up TCP Transparent mode failed ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Set up TCP Transparent mode succeeded ...\r\n\r\n");
    return 0;    // success , return 0
}
//4.TCP send data 
/** * @brief TCP send data  * * @param data： Data sent  * len： Length of data sent  * * @return void */
void FG_TCP_Send_Data(u8* data,u16 len)
{
    
    /* use DMA Send data by */
    HexArrayToString(data,(char*)USART1_TX_BUF,len);          // First, convert the original data into a string 
    HAL_USART1_DMA_TX(&USART1TxDMA_Handler,DMA_FLAG_TC2,&huart1,USART1_TX_BUF,2*len);// Use DMA send data 
    memset(USART1_TX_BUF,0,sizeof(USART1_TX_BUF));            // Empty cache 
}
//5. Wait for the data to be returned and processed ( Part of the code )
if(USART1_IDLE_FLAG)                     // A serial port 1 Receiving data is over , And NB Module communication 
{
    
       for(i=0;i<USART1_RX_COUNT;i++)   // Print out the received data 
       printf("%x ",USART1_RX_BUF[i]);     
       printf("\r\n");
       memset(USART1_RX_BUF,0,sizeof(USART1_RX_BUF));       // Empty cache , For the next use 
       USART1_RX_COUNT=0;                                   // Clear the number of bytes accepted 
       USART1_IDLE_FLAG=0;                                  // Idle interrupt flag reset 
}
//6. Module shutdown 
//4G To turn it off 
void FourG_Power_Off(void)
{
    
    POWERKEY(1);
    delay_ms(600);
    POWERKEY(0);
// fg_printf("AT+QPOWD\r\n"); // Send shutdown command 
}
EC20/25 4G The default serial port baud rate of the module is 115200, Sometimes you need to modify the baud rate , Function as follows :
/** * @brief FG Module set baud rate  * * @param void * * @return 0: Set up the success  * 1: Setup failed  */
u8 FourG_SET_Bund(void)
{
    
    u8 i=0;
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT",(u8 *)"OK",100)==0)break;
    if(i==3)
    {
    
        printf(" Module status is abnormal ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" The module status is normal ...\r\n\r\n");
 
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT+IPR=9600;&W",(u8 *)"OK",50)==0)break;  // Set the baud rate to 9600 And permanently stored in the module , The baud rate here can be modified as needed 
    if(i==3)
    {
    
        printf(" Set up 9600 Baud rate failed ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Set up 9600 Baud rate succeeded ...\r\n\r\n");
    
    return 0;
}

Four .UDP Data transmission process

1.POWERKEY Turn it on ----->2. Module networking ----->3. establish UDP Connect ----->4.UDP send data ----->5. Wait for the data to be returned and processed ----->6. Module shutdown （POWERKEY or AT Instructions ）.
Detailed procedure ：

// Related support functions ： ditto TCP
//1.4G Turn it on ： ditto TCP
//2. Module networking ： ditto TCP
//3. establish UDP Connect 
/** * @brief 4G 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:UDP Successful connection  * 1:UDP The connection fails  */
u8 FG_UDP_Connect(void)
{
    
    u8 i=0;
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT+QICSGP=1,1,\"MOBILE\",\"\",\"\",1",(u8 *)"OK",10)==0)break;
    if(i==3)
    {
    
        printf(" To configure TCP/IP Environment failure ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" To configure TCP/IP Environment success ...\r\n\r\n");
    
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT+QIACT=1",(u8 *)"OK",10)==0)break;
    if(i==3)
    {
    
        printf(" Activate TCP/IP Environment failure ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Activate TCP/IP Environment success ...\r\n\r\n");

    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)"AT+QIOPEN=1,2,\"UDP SERVICE\",\"127.0.0.1\",0,3030,1",(u8 *)"OK",10)==0)break;
    if(i==3)
    {
    
        printf(" Set up UDP Transparent mode failed ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Set up UDP Transparent mode succeeded ...\r\n\r\n");
    return 0;    // success , return 0
}
//4.UDP send data 
/** * @brief UDP send data  * * @param ip:ip Address  * port： Port number  * data： Data sent  * len： Length of data sent  * * @return 0:UDP Send successfully  * 1:UDP fail in send  */               
u8 FG_UDP_Send_Data(const u8* ip,const u8* port,u8* data,u16 len)
{
    
    u8 i=0;
    u16 waittime=1000;
    char p[50]={
    0};
    sprintf((char*)p,"AT+QISEND=2,%d,\"%s\",%s",2*len,ip,port);
    for(i=0;i<3;i++)
    if(fg_send_cmd((u8 *)p,(u8 *)">",10)==0)break;
    if(i==3)
    {
    
        printf(" Have not received > Failed to send data ...\r\n\r\n");
        return 1;    // Failure , return 1
    }
    else printf(" Acknowledge receipt of > Start sending data ....\r\n\r\n");
    /* use DMA Send data by */
    HexArrayToString(data,(char*)USART1_TX_BUF,len);          // First, convert the original data into a string 
    HAL_USART1_DMA_TX(&USART1TxDMA_Handler,DMA_FLAG_TC2,&huart1,USART1_TX_BUF,2*len);// Use DMA send data 
    memset(USART1_TX_BUF,0,sizeof(USART1_TX_BUF));            // Empty cache 
    while(--waittime)	                 // Wait for the countdown 
    {
    
        delay_ms(1);
        if(USART1_IDLE_FLAG)             // Received the expected response result 
        {
    
            if(fg_send_check_cmd((u8 *)"SEND OK"))
            {
    
               printf("ack: %s\r\n",(u8*)"SEND OK");
               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 0
            }
            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 1
}
//5. Wait for the data to be returned and processed , because UDP Not through transmission mode , Therefore, we need to process the most received data , You can deal with it yourself 
if(USART1_IDLE_FLAG)                     // A serial port 1 Receiving data is over , And NB Module communication 
{
    
                   received_length=0;
                   printf(" The received UDP The data is ：%s\r\n",USART1_RX_BUF);
                   /* Determine whether there is data from the server */
                   str1=fg_send_check_cmd(portnum);  // Judge whether the received data is +NSONMI:
                   str2=str1+portlen+2;              // Get the first address of the data area 
                   while(str2!=&USART1_RX_BUF[USART1_RX_COUNT-2])   // Not to the penultimate 
                   {
    
                       str2++;                       // Receive buffer goes down one position 
                       received_length++;            // Number of bytes received plus one 
                       if(received_length>180)break; // If the received data is greater than 180, Then it is judged that the reception is wrong , sign out while() loop 
                   }
                   printf("received_length=%d\r\n",received_length);
                   memmove(USART1_RX_BUF,str1+portlen+2,received_length);
                   USART1_RX_COUNT=received_length;
                   USART1_RX_BUF[USART1_RX_COUNT]=0;

               	   for(i=0;i<USART1_RX_COUNT;i++)
                   printf("%x ",USART1_RX_BUF[i]);     
                   printf("\r\n");
}
//6. Module shutdown ： ditto TCP

5、 ... and . summary

4G As the mainstream communication mode nowadays, communication has a very wide range of applications , Moving away from the company's EC20/25 As the mainstream 4G Communication modules are widely used , In addition, this module also has many other powerful functions , Such as low power consumption mode ,GNSS Positioning function , You can develop it yourself .TCP/UDP As a mainstream transmission protocol , This article provides a detailed development process , As a reference .