File content as of revision 1:79272efb4415:

#include "mbed.h"
#include "string.h"

Serial pc(SERIAL_TX, SERIAL_RX);
Serial sim808(D1,D0);
DigitalOut myled(LED1);
//Ticker beat;

#define buf_max 200
const char *string = "AT+CIPSTART=\"TCP\",\"116.31.51.113\",9015";
char *content="HELLO ~";
int First_Int = 0;
char sim_buf[buf_max];

void SIM808_IRQHandler(void);
void CLR_Buf(void);
void Wait_CREG(void);
int Find(char *a);
void send_beat(void);

//void getline();

void SIM808_IRQHandler(void)                    
{    
      sim_buf[First_Int] = sim808.getc();
            First_Int++; 
} 

int main()
{
    sim808.attach(&SIM808_IRQHandler,SerialBase::RxIrq);
    
    pc.printf("GPRS Connect Test!");
    wait(1);
    
    sim808.printf("AT");
    sim808.printf("\r\n");
    wait(1);
    pc.printf("%s",sim_buf);
    CLR_Buf(); 

    Wait_CREG();
    pc.printf("Register Succeed!");

    sim808.printf("AT+CIPCLOSE=1");//¹Ø±ÕÁ¬½Ó
    sim808.printf("\r\n");
    wait(1);
    pc.printf("%s",sim_buf);
    CLR_Buf();

    sim808.printf("AT+CIPSHUT");//¹Ø±ÕÒƶ¯³¡¾°
    sim808.printf("\r\n");
    wait(1);
    pc.printf("%s",sim_buf);
    CLR_Buf();

    sim808.printf("AT+CGCLASS=\"B\"");//ÉèÖÃGPRSÒƶ¯Ì¨Àà±ðΪB,Ö§³Ö°ü½»»»ºÍÊý¾Ý½»»» 
    sim808.printf("\r\n");
    wait(1);
    pc.printf("%s",sim_buf);
    CLR_Buf();

    sim808.printf("AT+CGDCONT=1,\"IP\",\"CMNET\"");//ÉèÖÃPDPÉÏÏÂÎÄ,»¥ÁªÍø½ÓЭÒé,½ÓÈëµãµÈÐÅÏ¢
    sim808.printf("\r\n");
    wait(1);
    pc.printf("%s",sim_buf);
    CLR_Buf();

    sim808.printf("AT+CGATT=1");//¸½×ÅGPRSÒµÎñ
    sim808.printf("\r\n");
    wait(1);
    pc.printf("%s",sim_buf);
    CLR_Buf();

    sim808.printf("AT+CIPCSGP=1,\"CMNET\"");//ÉèÖÃΪGPRSÁ¬½Óģʽ
    sim808.printf("\r\n");
    wait(1);
    pc.printf("%s",sim_buf);
    CLR_Buf();
    
    sim808.printf("AT+CIPHEAD=1");//ÉèÖýÓÊÕÊý¾ÝÏÔʾIPÍ·(·½±ãÅжÏÊý¾ÝÀ´Ô´,½öÔÚµ¥Â·Á¬½ÓÓÐЧ)
    sim808.printf("\r\n");
    wait(1);
    pc.printf("%s",sim_buf);
    CLR_Buf();
    
  sim808.printf("%s",(char*)string);
    wait(1);
    pc.printf("%s",sim_buf);
    CLR_Buf();
    
    sim808.printf("AT+CGDCONT=1");
    sim808.printf("\r\n");
    wait(1);
    pc.printf("%s",sim_buf);
    
    while(1)
 {
    if(Find("CONNECT OK")==1)
    {
        sim808.printf("%s",(char*)content);
    }
    else
    {
        pc.printf("Do Not Connected!");
    }
 }
    
//  beat.attach(&send_beat,10);
//  while(1);
}

//void send_beat(void)
//{
//  sim808.printf("AT+CIPSEND");
//  sim808.printf("\r\n");
//  pc.printf("%s",sim_buf);
//  if(Find("<")==1)
//  {
//      sim808.printf("OK");
//      CLR_Buf();
//  }
//  
//}

//void getline() 
//{
//  pc.putc(sim808.getc());
//}

void CLR_Buf(void)
{
    uint16_t k;
    for(k=0;k<buf_max;k++)      //½«»º´æÄÚÈÝÇåÁã
    {
        sim_buf[k] = 0x00;
    }
    First_Int = 0;              //½ÓÊÕ×Ö·û´®µÄÆðʼ´æ´¢Î»ÖÃ
}

int Find(char *a)
{ 
  if(strstr(sim_buf,a)!=NULL)
        return 1;
    else
            return 0;
}

void Wait_CREG(void)
{
    int i;
    int k;
    i = 0;
    CLR_Buf();
  while(i == 0)                 
    {
        CLR_Buf();        
        sim808.printf("AT+CREG?");
        sim808.printf("\r\n");
        wait(1);        
        pc.printf("%s\r\n",sim_buf);
        for(k=0;k<buf_max;k++)                  
        {
            if(sim_buf[k] == ':')
            {
                if((sim_buf[k+4] == '1')||(sim_buf[k+4] == '5'))
                {
                    i = 1;
                  break;
                }
            }
        }
        pc.printf("CREGING.....\r\n");
    }
}