4.4.c

来自「MSP430单片机的经典C语言例子」· C语言 代码 · 共 49 行

#include <msp430x14x.h>
char Key_Pressed(void);
void Led_Flash(void);

void main(void)
{
   unsigned char time ,delay,i;
   WDTCTL  =  WDTPW+WDTHOLD;
   P1DIR  &=~BIT2;
   P1DIR  |= BIT0;
   while(1)
     {
       if(Key_Pressed())
         time=(time+1)%4;
       switch (time)
           {
             case 0:delay  =  2;
                    break;
             case 1:delay  =  3;
                    break;       
             case 2:delay  =  5;
                    break;
             case 3:delay  =  7;
                    break;  
             default:break;            
           }  
        for(i=0;i<delay*2;i++)
           Led_Flash();   
     }

}

void Led_Flash(void)
{
  unsigned int i;
  for(i=0;i<20000;i++);
  P1OUT^=BIT0; 
}

char Key_Pressed(void)
{
  unsigned int i;
  while(!(P1IN&BIT2));
  for(i=0;i<8000;i++);
  if(P1IN&BIT2)
     return 1;
  else
     return 0;   
}