学习笔记分享 | 使用C库函数控制ELF 1开发板的LED

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

#define LED1_BRIGHTNESS "/sys/class/leds/led1/brightness" 
#define LED2_BRIGHTNESS "/sys/class/leds/led2/brightness"
#define LED3_BRIGHTNESS "/sys/class/leds/led3/brightness"

int main()
{
	FILE *fd1, *fd2, *fd3;

    fd1 = fopen(LED1_BRIGHTNESS, "w");
    if(fd1 < 0) {
      printf("Fail to Open %s devicen", LED1_BRIGHTNESS);
      exit(1);
   }

   fd2 = fopen(LED2_BRIGHTNESS, "w");
    if(fd2 < 0) {
      printf("Fail to Open %s devicen", LED2_BRIGHTNESS);
      exit(1);
   }

   fd3 = fopen(LED3_BRIGHTNESS, "w");
    if(fd3 < 0) {
      printf("Fail to Open %s devicen", LED3_BRIGHTNESS);
      exit(1);
   }

    while(1) {
      fwrite("1",3,1,fd1);
      fflush(fd1);

      sleep(1);

      fwrite("0",1,1,fd1);
      fflush(fd1);


      fwrite("1",3,1,fd2);
      fflush(fd2);

      sleep(1);

      fwrite("0",1,1,fd2);
      fflush(fd2);

      fwrite("1",3,1,fd3);
      fflush(fd3);

      sleep(1);

      fwrite("0",1,1,fd3);
      fflush(fd3);
    }

    fclose(fd1);
    fclose(fd2);
    fclose(fd3);
    return 0;
}