gpio in arch linux problems

[otniel]

Hello!

I managed to install arch linux on a raspberry pi 3. The problem is i cannot use the GPIO. Whenever i try, for example, echo "18" > /sys/class/gpio/export (and other numbers) it says invalid argument. I am root when executing echo. I cannot find a solution to solve this. What could be the problem?

[bob8889]

I'm no expert but I have this working on a RPi Zero W with this command using sudo:
echo "17" | sudo tee /sys/class/gpio/export
echo "out" | sudo tee /sys/class/gpio/gpio17/direction

[bob8889]

Just noticed that I ran this as root as well:
echo "17" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio17/direction