linux中应用程序控制led

1sch.高电平点亮

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2驱动设备节点

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3控制代码

#include <stdio.h>



//文件操作函数头文件
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <unistd.h>
#include <string.h>
#include <stdlib.h>

#define LED_NUM  2
#define LED_CMD  2

/*
cmd:0--->led off 1--->led on
io: 00-->靠近蜂鸣器的led  1---》靠近按键的led
*/
int main(int argc ,char **argv)
{
    
    int fd,led_num,led_cmd;
    char *led_path="/dev/leds";
    printf("\n argv1 is cmd,argv2 is io\n");
    printf("\ncmd:0--->led off 1--->led on\no: 00-->靠近蜂鸣器的led  1---》靠近按键的led\n");
    printf("app name:%s\n",argv[0]);
    led_cmd = atoi(argv[1]);
    led_num =atoi(argv[2]);
    if(led_cmd>LED_CMD)
    {
    printf("para1 len cmd err \n");
    exit(1);      

    }
    if(led_num>LED_NUM)
    {
    printf("para2 led err \n");
    exit(1);      

    }
    if((fd = open(led_path,O_RDWR|O_NOCTTY|O_NDELAY))<0)
    {
        
      printf("open path %s  err \n",led_path);
      exit(1);       
    }
        
    if((ioctl(fd,led_cmd,led_num))<0)
    {
         printf("led ioctl err \n");
        
    }else
    {
        
         printf("led ioctl success \n");
    }
    
    close(fd);
    return 0;
    
}

4控制命令

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