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nid help on LED blinking

i have problem with the led blinking. I using the exmaple program given by keil using uVision3. When i run the program, the LED on the development board didnt blink, it just stay on! wat should i do?

thanks!

Parents

0 james yeo over 16 years ago in reply to james yeo

is there any wrong with this code?

/* BLINKY.C - LED Flasher for the Keil MCBx51 Evaluation Board with 80C51 device*/

#include <REG8252.H>


// When you have enabled the option Stop Program Execution with Serial
// Interrupt, the Monitor-51 uses the serial interrupt of the UART.
// It is therefore required to reserve the memory locations for the interrupt
// vector.  You can do this by adding one of the following code lines:

 //char code reserve [3] _at_ 0x23;   // when using on-chip UART for communication
//char code reserve [3] _at_  0x3;   // when using off-chip UART for communication


void wait (void)  {                   /* wait function */
#define TF0_VECTOR 1

int R7=20;
TR0=0;
TF0=0;

TMOD=TMOD | 0xF0; //Timer 0,16 bit Timer
TMOD=TMOD & 0x01;

TL0=0xAF; //Timer 0, set 1 second
TH0=0x3C;
TR0=1; //start timer

while(R7!=0)
{
if(TF0!=0) //test if the timer overflow
{
TR0=0; //stop timer
TF0=0; //clear the overflow flag
R7--;
TR0=1;
}
}
                             /* only to delay for LED flashes */
}

void main (void)  {
  unsigned int i;                     /* Delay var */
  unsigned char j;                    /* LED var */

  while (1) {                         /* Loop forever */
   for (j=0x01; j< 0x80; j<<=1)  {   /* Blink LED 0, 1, 2, 3, 4, 5, 6 */

          P1 = j;
                    /* Output to LED Port */
      for (i = 0; i < 10; i++)  {  /* Delay for 10000 Counts */
       wait ();                       /* call wait function */
      }
    }

    for (j=0x80; j> 0x01; j>>=1)  {   /* Blink LED 6, 5, 4, 3, 2, 1 */
      P1 = j;
                                /* Output to LED Port */
      for (i = 0; i < 10; i++)  {  /* Delay for 10000 Counts */
       wait ();                       /* call wait function */
      }
    }
  }

}

Reply

0 james yeo over 16 years ago in reply to james yeo

is there any wrong with this code?

/* BLINKY.C - LED Flasher for the Keil MCBx51 Evaluation Board with 80C51 device*/

#include <REG8252.H>


// When you have enabled the option Stop Program Execution with Serial
// Interrupt, the Monitor-51 uses the serial interrupt of the UART.
// It is therefore required to reserve the memory locations for the interrupt
// vector.  You can do this by adding one of the following code lines:

 //char code reserve [3] _at_ 0x23;   // when using on-chip UART for communication
//char code reserve [3] _at_  0x3;   // when using off-chip UART for communication


void wait (void)  {                   /* wait function */
#define TF0_VECTOR 1

int R7=20;
TR0=0;
TF0=0;

TMOD=TMOD | 0xF0; //Timer 0,16 bit Timer
TMOD=TMOD & 0x01;

TL0=0xAF; //Timer 0, set 1 second
TH0=0x3C;
TR0=1; //start timer

while(R7!=0)
{
if(TF0!=0) //test if the timer overflow
{
TR0=0; //stop timer
TF0=0; //clear the overflow flag
R7--;
TR0=1;
}
}
                             /* only to delay for LED flashes */
}

void main (void)  {
  unsigned int i;                     /* Delay var */
  unsigned char j;                    /* LED var */

  while (1) {                         /* Loop forever */
   for (j=0x01; j< 0x80; j<<=1)  {   /* Blink LED 0, 1, 2, 3, 4, 5, 6 */

          P1 = j;
                    /* Output to LED Port */
      for (i = 0; i < 10; i++)  {  /* Delay for 10000 Counts */
       wait ();                       /* call wait function */
      }
    }

    for (j=0x80; j> 0x01; j>>=1)  {   /* Blink LED 6, 5, 4, 3, 2, 1 */
      P1 = j;
                                /* Output to LED Port */
      for (i = 0; i < 10; i++)  {  /* Delay for 10000 Counts */
       wait ();                       /* call wait function */
      }
    }
  }

}

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