This discussion has been locked.

You can no longer post new replies to this discussion. If you have a question you can start a new discussion

Timer

HiKarthik Ragunath Gopal over 17 years ago

I want 10 sec delay for the system how to implement
it in keil c. kindly help me.

for example: consider a road signal which has three aspects
and when the aspect changes from green to red it goes to yellow aspect and there is a delay of 5 to 10 sec. how to implement it. I implemented it by using for loops. But there is any way to implement using Hardware timer concepts

Parents

0 HiKarthik Ragunath Gopal over 17 years ago in reply to HiKarthik Ragunath Gopal

what about this program for 10 sec delay without interrupt.

#include<stdio.h>
#include <REG54.H>
#define   S  10                  /*select your time in seconds*/
void delay();
void main()
{
int i;
while(1)
{
P0=~P0;
for(i=0;i<20*S;i++)  /
delay();
}
}

void delay()                            /* delay  subroutine */
{
TMOD &= 0xF0; // Clear all T0 bits (T1 left unchanged)
TMOD |= 0x01; // Set required T0 bits (T1 left unchanged)
ET0 = 0; // No interupts
// Values for 50 ms delay
/*
    calculation for 50 ms
    (50ms/1000ms)*1000000=50000
        65536-50000=15536=3CB0
        TH0=3C
        TL0=B0
*/

TH0 = 0x3C; // Timer 0 initial value (High Byte)
TL0 = 0xB0; // Timer 0 initial value (Low Byte)
TF0 = 0; // Clear overflow flag
TR0 = 1; // Start timer 0
while (TF0 == 0); // Loop until Timer 0 overflows (TF0 == 1)
TR0 = 0; // Stop Timer 0
}

thanks,
vijay

Reply

0 HiKarthik Ragunath Gopal over 17 years ago in reply to HiKarthik Ragunath Gopal

what about this program for 10 sec delay without interrupt.

#include<stdio.h>
#include <REG54.H>
#define   S  10                  /*select your time in seconds*/
void delay();
void main()
{
int i;
while(1)
{
P0=~P0;
for(i=0;i<20*S;i++)  /
delay();
}
}

void delay()                            /* delay  subroutine */
{
TMOD &= 0xF0; // Clear all T0 bits (T1 left unchanged)
TMOD |= 0x01; // Set required T0 bits (T1 left unchanged)
ET0 = 0; // No interupts
// Values for 50 ms delay
/*
    calculation for 50 ms
    (50ms/1000ms)*1000000=50000
        65536-50000=15536=3CB0
        TH0=3C
        TL0=B0
*/

TH0 = 0x3C; // Timer 0 initial value (High Byte)
TL0 = 0xB0; // Timer 0 initial value (Low Byte)
TF0 = 0; // Clear overflow flag
TR0 = 1; // Start timer 0
while (TF0 == 0); // Loop until Timer 0 overflows (TF0 == 1)
TR0 = 0; // Stop Timer 0
}

thanks,
vijay

Children

No data