GPS clock 51 single chip microcomputer program

I have collected the GPS clock program I saw on the Internet for reference by electronics enthusiasts. The GPS clock has very simple hardware and the program is not too complicated. It does not require buttons or DS1302 IC. It only requires a GPS module. The advantage is that it does not require time adjustment. As long as there is a satellite signal, the time can be checked.

 

// Author: antlu

#include
#define DataPort P0 // display LED segment
#define DrivePort P2 //display LED digit
//sbit Gok_LED =P1^2; //Receive "$GPRMC," send LED
bit disp_flag;
bit rec; // receive rs232 OK_flag
void DelayUs2x(unsigned char t);//us delay function declaration
void DelayMs(unsigned char t); //ms?Delay?
void Display(unsigned char n,unsigned char Num); // Display the seven-segment display
unsigned char code segment[10]={ 0x3f,0x06,0x5b,0x4f,0x66,0x6d,0x7d,0x07,0x7f,0x6f};// VFD
unsigned char code grid[4]={ 0x01,0x02,0x04,0x08 };
// 10H H 10mm, Bit code 3>>minutes, Bit code 2>>10minutes, Bit code 1>>hours, Bit code 0>>10hours,
unsigned char TempData[4];
//, store the segment data in the buffer to be displayed, and send it to the display using a table-like mapping method. TempData[ ] is where the 7-segment data to be displayed is placed
unsigned char CLCK[6];
//void Display(char n,char Num);
unsigned char count;
void Display_Data_Operation(void) //Using time, minutes and seconds as the common language, convert the numbers into 7-segment display
{
   TempData[3]= segment[CLCK[0]];//?
   // if (CLCK[2]==0)
   // TempData[3]=0;
   TempData[2]= segment[CLCK[1]];//
   TempData[1]= segment[CLCK[2]]; //segment
   TempData[0]= segment[CLCK[3]];//
   //Display(0,4);   
}   
//------------------------------------------------ --------------------------
void Display(unsigned char n,unsigned char Num) // Display the seven-segment display
{
   unsigned char i;
   n=0; //It is no longer useful, but it is still set to 0 due to the previous programming.
   for(i=0;i
   {
      DataPort = TempData; //
      DrivePort = grid;      
      DelayMs(5); //0908 update Change 20 to 10 due to flashing >>5>>2
   }
}
void DelayUs2x(unsigned char t)
{  
   while(--t);
}
void DelayMs(unsigned char t)
{
    while(t--)
    {
       //About 1mS delay
       DelayUs2x(245);
       DelayUs2x(245);
    }
}
///////////////FROM GPS /////////////////////////////////// ///////////////////
unsigned char Gok; // "$GPRMC," confirmation completed
unsigned char REV_DATA; //temporary variable for storing RS232 buffer
void Init_Timer0(void); //Timer initialization
//----- FROM GPS PROG -----
void Init_Timer0(void)
{
    TMOD |= 0x01; //Use mode 1, 16-bit timer, use the "|" symbol to avoid being affected when using multiple timers.            
    EA=1; //? Hit?
    ET0=1; //Timer is on
    TR0=1; //Timer is on
}
void Timer0_isr(void) interrupt 1
{
    // static unsigned int count;
    TH0=(65536-2010)/256; //Reset value 2ms
    TL0=(65536-2010)%6;
    count++;
    if (count==10)
    {
       count=0;
       disp_flag=1;
    }
}
void UART_Init(void)
{
    SCON = 0x50; // SCON: Mode 1, 8-bit UART, receive enabled
    TMOD |= 0x20; // TMOD: timer 1, mode 2, 8-bit heavy?
    TH1 = 0xFA; // TH1: reset to 4800 11.0592MHz
    TR1 = 1; // TR1: timer 1 hit?                        
    EA = 1; // Hit?
    ES = 1; //Open the serial port?
}
void UART_SER (void) interrupt 4 //from serial port clock 1602 program
{
     if(RI) //Judge whether it is receiving
     {
      RI=0; //? Clear the flag
      REV_DATA = SBUF; //Enter the value of
      rec=1;
     //rec_led=1;
     }
     if(TI) //If it is a send flag, clear it
     TI=0;
}
unsigned char GPRMC_K(void)//Compare $GPRMC
{
    unsigned char TT; // conversion
    while(rec==0);
    if(rec==1)
    if(REV_DATA == 'G') //Compare all the way to the same "GPRMC,"
    rec=0;
    else
    return 0;
    while(rec==0);       
    if(rec==1)        
    if(REV_DATA == 'P')          
    rec=0;   
    while(rec==0);       
    if(rec==1)        
    if(REV_DATA == 'R') //Compare all the way to the same "GPRMC,"          
    rec=0;        
    else
    return 0;        
    while(rec==0);       
    if(rec==1)        
    if(REV_DATA == 'M') //Compare all the way to the same "GPRMC,"          
    rec=0;   
    while(rec==0);       
    if(rec==1)        
    if(REV_DATA == 'C') //Compare all the way to the same "GPRMC,"          
    rec=0;
    while(rec==0);    
    if(rec==1)    
    if(REV_DATA == ',') //Compare all the way and all must be the same "GPRMC,"
    rec=0;
    else
    return 0;
    while(rec==0);      
    if(rec==1)                
    CLCK[0]=REV_DATA-0x30;//10hr
    rec=0;                    
    while(rec==0);      
    if(rec==1)                
    CLCK[1]=REV_DATA-0x30;//1hr
    rec=0;                  
    while(rec==0);      
    if(rec==1)                
    CLCK[2]=REV_DATA-0x30;//10min
    rec=0;                  
    while(rec==0);       
    if(rec==1)                
    CLCK[3]=REV_DATA-0x30;//1min
    rec=0;         
    while(rec==0);       
    if(rec==1)                
    CLCK[4]=REV_DATA-0x30;//10sec
    rec=0;         
    while(rec==0);       
    if(rec==1)                
    CLCK[5]=REV_DATA-0x30;//sec        
    TT=CLCK[0]*10+CLCK[1]+8;
    if(TT>23)
    TT-=24;
    CLCK[0]=TT/10;
    CLCK[1]=TT;
    return 1;
}
void Get_Gps(void)
{
    if(rec==1)
    {
       rec=0; //Clear the credit flag
       if(REV_DATA == '$')
       {
          Gok=GPRMC_K(); //Confirm receipt of "GPRMC," character
       }
    }
}
// --------- GPS MAIN PROGRAM -------------
void main(void)
{
    Init_Timer0();
    UART_Init();
    while(1)
    {
        Get_Gps();
        if(Gok==1)
        {
           Display_Data_Operation (); //Convert relevant values ​​to display
        }
 if(disp_flag==1)
        {
           disp_flag=0;
           Display(0,4);
        }
        Display(0,4);
    }
}