simple_test_driver.c

Linux环境下的嵌入式编程,即实现led的按时间亮

#include <stdio.h>
#include <string.h>
#include <stdlib.h>

#include <fcntl.h>      // open() close()
#include <unistd.h>     // read() write()


#define DEVICE_NAME "/dev/led_ary_ctl"


//------------------------------------- main ----------------------------------------------------------------
int main(void)
{
	int fd;
	int ret;
	unsigned char buf[2] ;
	unsigned char c,r;
	int i,j;
	
	// begin of led ary
	c = 1;
	r = 1;

        printf("\nstart led_driver test\n\n");

        fd = open(DEVICE_NAME, O_RDWR);
	
	printf("fd = %d\n",fd);
	
        if (fd == -1) {
		printf("open device %s error\n",DEVICE_NAME);
        }
        else {
		for (i=1;i<=8;i++) {
			buf[0]=c;
			buf[1]=~r; // row
			for (j=1;j<=8;j++) {
				write(fd,buf,2);
				printf ("buf[0],buf[1]: [%x,%x]\n",buf[0],buf[1]);
				usleep(200000); // sleep 0.2 second
				c = c<<1;
                                c = c<<1;
				buf[0]=c; // column 
	    		}
			c = 1;
	  		r = r<<1;
	  	}
		// close 
		ret = close(fd);
		printf ("ret=%d\n",ret);
		printf ("close led_driver test\n");
	}

        return 0;
}// end main