leddemo.c

一个在uClinux下做的最简单的控制led的程序

#include <stdio.h>

/*
 * LED blink function. 
 *     this function blink the led
 */
void led_blink(void)
{
	static int led_status = 0;
	
	led_status += 1;
	if(led_status % 2 == 0)
		*(char *)0x02000000 = 0xff;
	else
		*(char *)0x02000000 = 0x00;			
}

/*
 * LED blink function. 
 *     this function blink the led
 */
void seg_blink(void)
{
	static unsigned char seg_value[] = { 0xc0, 0xf9, 0xa4, 0xb0, 0x99, 0x92, 0x82, 0xf8, 0x80, 0x90, 0x88, 0x83, 0xc6, 0xa1, 0x86, 0x8e };		   
	static int seg_status = 0;
	
	*((unsigned char *)0x02000004) = seg_value[seg_status];
	seg_status += 1;
	if(seg_status > 15)
		seg_status = 0;
}

int main()
{
	int loopcnt;
	printf("hello world!!!\n");

	*((unsigned char *)0x02000006) = 0x3e;
	while(1)
	{
		led_blink();
		seg_blink();
		sleep(1);
	}
	return 0;
}