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以下shell命令切換Leopardboard GPIO 31就好:如何控制embedded-linux gpio?
echo 31 > /sys/class/gpio/export
echo out > /sys/class/gpio/gpio31/direction
echo 0 > /sys/class/gpio/gpio31/value
echo 1 > /sys/class/gpio/gpio31/value
echo 0 > /sys/class/gpio/gpio31/value
This被用作用於以下的代碼的例子。 任何想法爲什麼下面的.vala代碼不會切換gpio 31?
public void sync() {
int fd = -1;
fd = open("/sys/class/gpio/export", O_WRONLY);
if (fd < 0) {
GLib.stdout.printf("Error sync export\n");
return;
}
write(fd, "31", 3);
close(fd);
fd = open("/sys/class/gpio/gpio31/direction", O_WRONLY);
if (fd < 0) {
GLib.stdout.printf("Error sync direction\n");
return;
}
write(fd, "out", 4);
close(fd);
fd = open("/sys/class/gpio/gpio31/value", O_WRONLY);
if (fd < 0) {
GLib.stdout.printf("Error sync value\n");
return;
}
write(fd, "0", 2);
write(fd, "1", 2);
Thread.usleep (1000); /* 1ms */
write(fd, "0", 2);
close(fd);
}