Đồng hồ số dùng DS1307

[HueDN]

Đây là code của đồng hồ 6 digit của TMdùng để học tập. Tuy nhiên vì mới học PIC nên chưa hiểu được. Nhất là chổ MAP đó. Các cao thủ giải thích dùm nhé

/****************************************************************   
* Real time Clock DS1307 
* Dong ho so su dung DS1307 hien thi tren 6 LED 7-segment hh.mm.ss
* Sofware: Compiler CCS Ver 4.018
* Harware: TMe - EasyPIC: (www.tme.com.vn)
   - Pull up PORTD, Pull-down Switches, connect PORTD to Switches
   - Switches: T1 - Mode, T2 - set time, T3 - clean status
   - DIP Swich SW2 all ON (Enable 7-segment and RTC DS1307)
*****************************************************************/

#include <16F877A.h>
#include <def_877a.h> //file header do nguoi dung dinh nghia
#include <ds1307.c>
#fuses   HS,NOWDT,NOPROTECT,NOLVP
#use     delay(clock=12000000)

byte sec,min,hour;
byte const MAP[10] = {0xC0,0xF9,0xA4,0xB0,0x99,0x92,0x82,0xF8,0x80,0x90};//Cathode
byte DIS1,DIS2,DIS3,DIS4,DIS5,DIS6;
byte key,mode;
int1 ampm,blink,blink_sec,blink_min,blink_hour;
int1 on_off;
int16 count;

#bit SW1   = 0x8.0  // D0 - mode
#bit SW2   = 0x8.1  // D1 - set_time 
#bit SW3   = 0x8.2  // D2 - Clear_status

void set_blink();
void change_time();
void update_1307();
void keyscan();
void set_sec();
void set_min();
void set_hour();
void clear_status();
void read_time();
void update_time();
void display();

//===============================================


void set_blink()
{

   switch (mode)
   {
      case 1:  blink_sec=1;   break;
      case 2: {blink_min=1;blink_sec=0;}   break;
      case 3: {blink_hour=1;blink_min=0;} break;
      case 4:
      {
         blink=0;mode = 0;blink_sec=0;
         blink_min=0;blink_hour=0;
      }
      break;
   }
}

void change_time(){ //Ham chon che do, giong nhu o dong ho CASIO, nhan 1 lan la phut, 2 lan la gio....

   if(mode == 1) {blink_sec=1;set_sec();}
   if(mode == 2) {blink_min=1;set_min();}
   if(mode == 3) {blink_hour=1;set_hour();}
   if(mode == 4)
   {
      blink=0;mode = 0;
      blink_sec=0; blink_min=0; blink_hour=0;
   } 
}


void update_1307() 
{
   write_DS1307(0,sec);
   write_DS1307(1,min);
   bit_set(hour,6);
   if (ampm == 0) {bit_clear(hour,5); write_DS1307(2,hour);} // AM
   if (ampm == 1) {bit_set  (hour,5); write_DS1307(2,hour);} // PM
   
}
void keyscan() {
   RD0=1;RD1=1;RD2=1;RD3=1;
   if(SW1 != 1)   { key=0;SW1=1;delay_ms(150);}
   if(SW2 != 1)   { key=1;SW2=1;delay_ms(150);}
   if(SW3 != 1)   { key=2;SW3=1;delay_ms(150);}
   if(key != 5)
     {
      switch (key)
      {
         case 0: {mode++;key = 5;blink=1;set_blink();}
         break;
         case 1: {change_time();key = 5;update_1307();}
         break;
         case 2: {clear_status();key = 5;}
         break;  
      }
    }
}

void set_sec()
{
       sec=read_ds1307(0);
       if (sec>=0x30) {sec=0; min++; write_ds1307(1,min);}
       else sec=0;
       write_ds1307(0,sec);
}
void set_min()
{ byte j;
 
            min=read_ds1307(1);
            min++;
            j=min & 0x0F;
            if (j>=0x0A) min=min+0x06;
            if (min>=0x60) min=0;
            write_ds1307(1,min);
}
void set_hour()
{  
   hour= hour & 0x1F;
   hour++;
   if(hour== 0x0a) hour = hour+0x06;
   if(hour == 0x13)
   { hour = 0x00;
     if (ampm == 0) ampm = 1;
     else ampm = 0;
   }
}

void clear_status() {

 mode=4;  set_blink();
}
void read_time() 
{
     sec  = read_DS1307(0);
     min  = read_DS1307(1);
     hour = read_DS1307(2);
     update_time();
}

void update_time()
{
  
   ampm = bit_test(hour,5);   //test AM PM
   if(ampm == 0)  {RD4 = 0;RD5=1;}   //AM
   if(ampm == 1)  {RD4 = 1;RD5=0;}   // PM
    DIS1= sec & 0x0F;
    DIS2=(sec & 0xF0)>>4; //convert to BCD SEC
    DIS3= min & 0x0F;
    DIS4=(min & 0xF0)>>4; //convert to BCD MIN
    DIS5= hour & 0x0F;
    DIS6=(hour & 0x10)>>4; //convert to BCD HOUR
   
}
void display() {
TRISB=0x00;TRISA=0x00;
   if(blink==0) goto norm;
   if(on_off==0) goto led_blink;
norm:
// sec - min - hour
      PortB=MAP[DIS1];  RA5=0;//DIS1
      delay_ms(1);         RA5=1;
      PortB=MAP[DIS2];  RA4=0;  //DIS2
      delay_ms(1);         RA4=1;
      PortB=MAP[DIS3];output_low(PIN_B7);RA3=0;//DIS3
      delay_ms(1);         RA3=1;
      PortB=MAP[DIS4];  RA2=0;//DIS4
      delay_ms(1);         RA2=1;
      PortB=MAP[DIS5];output_low(PIN_B7);  RA1=0;//DIS5
      delay_ms(1);         RA1=1;
      PortB=MAP[DIS6];if (portb==0xC0) RA0=1; else RA0=0;//DIS6
      delay_ms(1);         RA0=1;//*/
      
      if(count!=0) goto exit;
      else
      {
         count=15;
         on_off=0;
      }
      goto exit;
      
led_blink:
      PortB=MAP[DIS1];
      if (blink_sec==1) RA5=1;//DIS1
      else RA5=0;
      delay_ms(3);         RA5=1;
      PortB=MAP[DIS2];
      if (blink_sec==1) RA4=1;//DIS2
      else RA4=0;
      delay_ms(3);         RA4=1;
      PortB=MAP[DIS3];output_low(PIN_B7);
      if(blink_min==1)     RA3=1;//DIS3
      else RA3=0;//DIS3
      delay_ms(3);         RA3=1;
      PortB=MAP[DIS4];
      if(blink_min==1)     RA2=1;//DIS4
      else RA2=0;//DIS4
      delay_ms(3);         RA2=1;
      PortB=MAP[DIS5];output_low(PIN_B7);
      if(blink_hour==1)    RA1=1;//DIS5
      else RA1=0;//DIS5
      delay_ms(3);         RA1=1;
      PortB=MAP[DIS6];
      if(blink_hour==1)    RA0=1;//DIS6
      else {if (portb==0xC0) RA0=1; else RA0=0;}//DIS6
      delay_ms(3);         RA0=1;//*/
      if(count==0) {count=15;on_off=1;}
      
exit:
      count--;
}
void main() {
byte u;
 Delay_ms(5);
 Trisd = 0x0F;
 Trisb = 0x00;//output
 Trisa = 0x00;
 RD4=1;RD5=1;
 init_ds1307();
 u=read_ds1307(0);
 sec=u & 0x7F;// enable RTC
 write_ds1307(0,sec);// set second to 00 and enable clock(bit7=0)

//Xoa tat ca cac co dieu khien
 key=5;mode=0;blink=0;
 blink_sec=0;blink_min=0;blink_hour=0;
 count=15;on_off=1;
   ampm = bit_test(hour,5);// test AM_PM
   if(ampm==0)  {RD4 = 0;RD5=1;}   //LED AM 
   if(ampm==1)  {RD4 = 1;RD5=0;}   //LED PM
while(true) 
   {
   read_time();
   display();
   keyscan();
   }
}//end of main program