xtest08_5.c

AT91sam7s 256 B/D example

/* ========================================================================== */
/*       Xtest08_5.c : Key Input Count with Debouncing by PIO Interrupt       */
/* ========================================================================== */
/*			  Designed and programmed by Duck-Yong Yoon in 2007.  */

#include "AT91SAM7S256.h"
#include "lib_AT91SAM7S256.h"
#include "OK7S256ads.h"

void LCD_3d(unsigned int number)		/* display 3-digit decimal number */
{ unsigned int i, flag;

  flag = 0;
  i = number/100;				// 10^2
  if(i == 0) LCD_data(' ');
  else {     LCD_data(i + '0');
             flag = 1;
       }

  number = number % 100;			// 10^1
  i = number/10;
  if((i == 0) && (flag == 0))
             LCD_data(' ');
  else {     LCD_data(i + '0');
             flag = 1;
       }

  i = number % 10;				// 10^0
  LCD_data(i + '0');
}

unsigned int key1=0, key2=0;			// key input counter

void PIO_ISR(void)				/* PIO interrupt service routine */
{ unsigned int status;

  Delay_ms(20);					// delay for debouncing
  status = (AT91F_PIO_GetInput(AT91C_BASE_PIOA) >> 7) & 0x00000003;
  if(status == 3)				// if key off, don't count and return
    { status = AT91F_PIO_GetInterruptStatus(AT91C_BASE_PIOA);
      return;
    }
  else						// if key on, beep and count
    Beep();

  status = (AT91F_PIO_GetInterruptStatus(AT91C_BASE_PIOA) >> 7) & 0x00000003;
  if(status == 1)				// if KEY1, display KEY1 count
    { key1++;					// increment and display count
      if(key1 > 999) key1 = 0;
      LCD_command(0x8A);
      LCD_3d(key1);
    }
  else if(status == 2)				// if KEY2, display KEY2 count
    { key2++;
      if(key2 > 999) key2 = 0;
      LCD_command(0xCA);
      LCD_3d(key2);
    }
}

int main(void)
{
  MCU_initialize();				// initialize AT91SAM7S256 & kit
  Delay_ms(50);					// wait for system stabilization
  LCD_initialize();				// initialize text LCD

  LCD_string(0x80,"   KEY1 = 000   ");		// display title on text LCD
  LCD_string(0xC0,"   KEY2 = 000   ");
  Beep();

  AT91F_PIO_InputFilterEnable(AT91C_BASE_PIOA,KEY2|KEY1); // initialize PIO interrupt
  AT91F_PIO_InterruptEnable(AT91C_BASE_PIOA,KEY2|KEY1);
  AT91F_AIC_ConfigureIt(AT91C_BASE_AIC,AT91C_ID_PIOA,7,1,PIO_ISR);
  AT91F_AIC_EnableIt(AT91C_BASE_AIC,AT91C_ID_PIOA);
  
  while(1);					// wait for interrupts
}