static int
GPIOUnexport(int pin)
{
char buffer[BUFFER_MAX];
ssize_t bytes_written;
int fd;
fd = open("/sys/class/gpio/unexport", O_WRONLY);
if (-1 == fd) {
fprintf(stderr, "Failed to open unexport for writing!\n");
return(-1);
}
bytes_wri
我正在使用pyudev来检测何时将usb设备放置在raspberry pi中。但是我需要得到它的文件目录,以便在我检测到它后将excel文件保存在usb中 代码为: import pyudev
import RPi.GPIO as GPIO
import time
from time import sleep
from os import path
#FUNCION PARA DETECTAR USB Y GUARDAR DATOS
def guardarUSB():
context = pyudev.Context()
monitor = pyudev.Monitor.fro
我使用Python 3.7.3在我的Raspberry Pi 4B上运行以下代码: from time import sleep
import RPi.GPIO as GPIO
import math
from watchgod import watch
g=open("/home/pi/Desktop/Int2/DesHeight.txt","r")
DesHeight = g.readline()
DesHeight1=float(DesHeight)
print(DesHeight1)
GPIO.cleanup()
DIR = 20
STEP =
我想知道“gpio索引”的含义是什么。
这就是我在of_gpio.h中看到的
/**
* of_get_named_gpio() - Get a GPIO number to use with GPIO API
* @np: device node to get GPIO from
* @propname: Name of property containing gpio specifier(s)
* @index: index of the GPIO
*
* Returns GPIO number to use with Linux generic GPIO API, o
我在和pi3B玩的时候发现了一件奇怪的事情。我想在/sys/class/gpio中创建一个文件(只是随便找找,没有具体的原因),但是我的Permission被拒绝了。下面是一些信息。
pi@raspberrypi:/sys/class/gpio $ groups
pi adm dialout cdrom sudo audio video plugdev games users input netdev gpio i2c spi
pi@raspberrypi:/sys/class/gpio $ ls -ld .
drwxrwx--- 2 root gpio 0 May 6 00:28 .
pi