I need help please

[marianspy]

Please help me solve the following problem: I got the code on your website at this address

http://www.engineersgarage.com/microcontroller/8051projects/countdown-timer-using-AT89C51-circuit

 

If you can tell me how to do my work throughout the buzzer on and off when the timer reaches zero.
What needs to change in this code?

 

 

// Program to make a timer similar to the timer in microwave. This countdown timer counts backwards from a set value and raise an alarm when the counting is complete.It also has a feature of pause.

#include<reg51.h>

sbit dig_ctrl_4=P1^0; //Declare the control pins for the seven segment
sbit dig_ctrl_3=P1^1;
sbit dig_ctrl_2=P1^2;
sbit dig_ctrl_1=P1^3;

sbit reset=P1^7;   //Reset pin to reset the timer.
sbit start=P1^6;  //Start pin to start the clock after the time is set.
sbit incr=P1^5;  //Increment pin to increase the digits for time setting.
sbit set=P1^4;  // Set pin to set the time.
sbit pause=P3^3; // Pause pin to pause the operation
sbit buzzer_pin=P3^7;

int sel_seg_to_incr=0;
int ret_seg_to_incre=0;
int recent_incr_seg;
int begin;
unsigned char dig_disp=0;
int min2=0;
int min1=0;
int sec2=0;
int sec1=0;
int p;
int avi=0;

char dig_val[10]={0x40,0xF9,0x24,0x30,0x19,0x12,0x02,0xF8,0x00,0x10};// Hex values corresponding to digits 0 to 9

void delay(int a)  // Function to provide a time delay of approx. one second using Timer 1.
{
int i;
  for(i=0;i<a;i++)
    {
  TL1=0xFD;
     TH1=0x4B;
     TR1=1;
   while(TF1==0);
   TR1=0;
   TF1=0;
}       
}

int setfn()  // Function to select minute and seconds digit to set value.
{     
while(set==0)
{

  switch(recent_incr_seg)
  {
   case 1:
   if(set==0)//select the min2 digit
   {
    dig_ctrl_4=1;
    dig_ctrl_3=0;
    dig_ctrl_2=0;
    dig_ctrl_1=0;
    recent_incr_seg=1;
    ret_seg_to_incre=1;
    P2=dig_val[min2];
    delay(15);
   }

   case 2:
   if(set==0)//select the min1 digit
   {
    dig_ctrl_4=0;
    dig_ctrl_3=1;
    dig_ctrl_2=0;
    dig_ctrl_1=0;
    recent_incr_seg=2;
    ret_seg_to_incre=2;
    P2=dig_val[min1];
    delay(15);
   }

   case 3:
   if(set==0)//select the sec 2 digit
   {
    dig_ctrl_4=0;
    dig_ctrl_3=0;
    dig_ctrl_2=1;
    dig_ctrl_1=0;
    recent_incr_seg=3;
    ret_seg_to_incre=3;
    P2=dig_val[sec2];
    delay(15);
   }

   case 4:
   if(set==0)//select the sec1 digit
   {
    recent_incr_seg=1;
    dig_ctrl_4=0;
    dig_ctrl_3=0;
    dig_ctrl_2=0;
    dig_ctrl_1=1;
    ret_seg_to_incre=4;
    P2=dig_val[sec1];
    delay(15);
    recent_incr_seg=1;
   }
  }
}
return(ret_seg_to_incre);
}

void increase(int a) //Function to set the minutes or seconds digit
{
while(incr==0)
{
  switch(a)
  {
   case 1: // Set the min2 digit.
   P2=dig_val[min2];
   delay(15);
   min2++;
   if(min2==6)
   min2=0;
   P2=dig_val[min2];
   delay(5);
   break;

   case 2: //Set the min1 digit.
   P2=dig_val[min1];
   delay(15);
   min1++;
   if(min1==10)
   min1=0;
   P2=dig_val[min1];
   delay(5);
   break;
 
   case 3:// Set the sec2 digit.
   P2=dig_val[sec2];
   delay(15);
   sec2++;
   if(sec2==6)
   sec2=0;
   P2=dig_val[sec2];
   delay(5);
   break;

   case 4://Set the sec1 digit.
   P2=dig_val[sec1];
   delay(15);
   sec1++;
   if(sec1==10)
   sec1=0;
   P2=dig_val[sec1];
   delay(5);
   break;
  }
}
}

void resetfn() // This function brings the clock to reset or set mode.
{

IE=0x84; // Disable Timer0 interrupt to stop the display of the clock
sel_seg_to_incr=1;
recent_incr_seg=1;
if(begin==0)
{
  dig_ctrl_4=1; //Enable the min2 digit and disable others
  dig_ctrl_3=0;
  dig_ctrl_2=0;
  dig_ctrl_1=0;
}
begin=0;
P2=dig_val[min2];
delay(5);
while(1)
{  
  if(start==0) //Check if start pin is pressed
  {
   TMOD=0x11; //Reset the Timer0
   TL0=0xf6;
   TH0=0xFf;
   IE=0x86;
   TR0=1;
   break;
  }

  if(set==0)
  sel_seg_to_incr=setfn();

  if(incr==0)
  increase(sel_seg_to_incr);
}
}

void display() interrupt 1  // Function to display the digits on seven segment using multiplexing.
{
TL0=0x36;//Reload Timer0
    TH0=0xf6;
P2=0xFF;
dig_ctrl_1 = dig_ctrl_3 = dig_ctrl_2 = dig_ctrl_4 = 0;
dig_disp++;
dig_disp=dig_disp%4;

switch(dig_disp)
{
  case 0:
  P2=dig_val[sec1];
  dig_ctrl_1 = 1;
  break;
  case 1:
  P2= dig_val[sec2];
  dig_ctrl_2 = 1;
  break;

  case 2:
  P2= dig_val[min1];
  dig_ctrl_3 = 1;
  break;

  case 3:
  P2= dig_val[min2];
  dig_ctrl_4 = 1;
  break;
}

}

void pauselock() interrupt 2//Function for pause mode
{
avi=1;
}

void main()
{
pause=1;
set=1; //Delaring set, reset, start and incr as input pins
reset=1;
start=1;
incr=1;
recent_incr_seg=1;
begin=1;
TMOD=0x11; //Intialize Timer0
TL0=0x36;
TH0=0xF6;
IE=0x86;
TR0=1;   //Trigger Timer0
  while(1) // Back counting.
  {
    while(min2>=0)
    {        
      while(min1>=0)
       {
     while(sec2>=0)
    {
     while(sec1>=0)
     {
     p=1;
       while(min2==0&&min1==0&&sec2==0&&sec1==0&&reset!=0&&begin==0)
       {
       if(p==1)
       {
       buzzer_pin=0;
       delay(50);
       buzzer_pin=1;
       p++;
       }
      }
    
     if(reset==0 || begin==1)
      {
       dig_ctrl_4=1;//Enable all segments
     dig_ctrl_3=1;
     dig_ctrl_2=1;
     dig_ctrl_1=1;
      resetfn();
     }
 
     while(avi==1&&start==1);
     avi=0;
     delay(20);
     sec1–;
    }
    sec1=9;
    sec2–;
   }
   sec1=9;
   sec2=5;
   min1–;
  }
  sec1=9;
  sec2=5;
  min1=9;
  min2–;
}
min2=5;
}
}

 

[marianspy]

Nobody can help me even with an opinion?

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