key.c

来自「周立公smartarm开发板gpio例子」· C语言 代码 · 共 80 行

/*
***************************************************************************************************
** GPIO input testing program.
** Press KEY1, LED light on and shutdown if released.
***************************************************************************************************
*/

#define IN_TGPIO
#include "config.h"

#define KEY1    20    //P0.20 connected to KEY1
#define LED     28    //P2.28 controles LED

void delayms(uint32 delay)
{
    uint32 i;
    for( ; delay>0; delay--)
        for(i=0; i<5000; i++);
}
    
int main()
{
    int fd1, fd2;
    uint32 pin = KEY1;
   
    fd1 = open("/dev/P0", O_RDONLY);
    if(fd1 == -1)
    {
        printf("\nCan't open P0!\n");
        return -1;
    }

    fd2 = open("/dev/P2", O_RDONLY);
    if(fd2 == -1)
    {
        printf("\nCan't open P2!\n");
        return -1;
    }
    
    printf("\nTest GPIO input(KEY), P0.20--KEY1\nPress KEY1, LED light on and shut down if released.\n");

    // set IO Direction 
    ioctl(fd1, GPIO_SET_PIN_IN, KEY1);
    ioctl(fd2, GPIO_SET_PIN_OUT, LED);
    
     while(1)
    {
        pin = KEY1;
        ioctl(fd1, GPIO_READ_PIN, &pin);
        while(pin != 0) 
        {// have no key ,continue read pin
            ioctl(fd2, GPIO_SET_PIN, LED);
            pin = KEY1;
            ioctl(fd1, GPIO_READ_PIN, &pin);
        }
        // have key, delay
        delayms(10);    // delay

        // after delay, read pin again 
        pin = KEY1;
        ioctl(fd1, GPIO_READ_PIN, &pin);
        while(pin == 0) // if key released,go on read pin
        {// remain 0, key pressed, 
            ioctl(fd2, GPIO_CLR_PIN, LED);
        //    ioctl(fd2, GPIO_SET_PIN, LED);
            pin = KEY1;
            ioctl(fd1, GPIO_READ_PIN, &pin);
        }
      //  ioctl(fd2, GPIO_CLR_PIN, LED);
    }

//    close(fd);
    return 0;
}


/*********************************************************************************************************
 **                            End Of File
********************************************************************************************************/