Controlling GPIO's

This short tutorial describes how to get GPIO working. For this you need tool called gpioctl.

• Type make menucongfig
• Under Utilities select package gpioctl and build carambola firmware (although you can do it directly on carambola typing opkg update; opkg install gpioctl)
• In latest OpenWrt revisions gpioctl become deprecated.

gpioctl dirout 1;  gpioctl dirout 2

gpioctl set 1; gpioctl set 2

gpioctl clear 1; gpioctl clear 2

gpioctl dirin 1; gpioctl dirin 2; gpioctl get 1; gpioctl get 2

Another method for controlling gpios using files instead of commands:

cd /sys/class/gpio
echo 1 > export 

this will make the virtual directory "gpio1" available in /sys/class/gpio/gpio1 inside "gpio1" you will find, among others:

• direction ("in" or "out")
• value (0 or 1)

Just write/read those file to do I/O. For example

echo out > direction
echo 1 > value

will put the pin in output mode and high

echo in > direction
cat value

will read the pin instead