button-test.c

2440 下的5*5按键驱动程序.请参看具体代码内容.

#include <stdio.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>

#define NOKEY 0

int main()
{
	int key7_fd;	
        char ret[2]; 
      
        key7_fd = open("/dev/key7", O_RDONLY);
	if(key7_fd<0)
	{
                printf("open key7 device error!\n");
		return 0;
	}
        else{
              printf("key7 is opened!");
           }

	while(1)
	{	
                read(key7_fd,ret,1);

		if (ret[0] != NOKEY)
		{
			printf("key = %c\n",ret[0]);
			
		}
		usleep(100000);
	}	
	close(key7_fd);
	
        return 0;
}