BBB板子中的GPIO引脚中断输入，下降沿触发

原创

于 2018-05-17 14:22:06 发布 · 1.7k 阅读

CC 4.0 BY-SA版权

#include<stdlib.h>
#include<stdio.h>
#include<string.h>
#include<unistd.h>
#include<fcntl.h>
#include<poll.h>

#define MSG(args...) printf(args) 

//函数声明
static int gpio_export(int pin);
static int gpio_unexport(int pin);
static int gpio_direction(int pin, int dir);
static int gpio_write(int pin, int value);
static int gpio_read(int pin);
static int gpio_edge(int pin, int edge);


static int gpio_export(int pin)  
{  
    char buffer[64];  
    int len;  
    int fd;  
  
    fd = open("/sys/class/gpio/export", O_WRONLY);  
    if (fd < 0) 
    {  
        MSG("Failed to open export for writing!\n");  
        return(-1);  
    }  
  
    len = snprintf(buffer, sizeof(buffer), "%d", pin);  
    printf("%s,%d,%d\n",buffer,sizeof(buffer),len);
    if (write(fd, buffer, len) < 0) 
    {  
        MSG("Failed to export gpio!");  
        return -1;  
    }  
     
    close(fd);  
    return 0;  
}  
static int gpio