How to use GPIO Raspberry Pi 2 (Model B v1.1 2014) based on Raspbian OS

How to use GPIO Raspberry Pi 2
(Model B v1.1 2014)
based on Raspbian OS

Basic using GPIO with shell, example with led blink

J8 header connector on Raspberry Pi 2 Model B v1.1 2014

Connect Led between GPIO4 and GND with 1K resistor.

Make sure root to gpio access:
$ sudo su

Command line probe:
# echo "4" > /sys/class/gpio/export
# echo "out" > /sys/class/gpio/gpio4/direction
# echo "1" > /sys/class/gpio/gpio4/value
# echo "0" > /sys/class/gpio/gpio4/value
# echo "4" > /sys/class/gpio/unexport


Create file: "ledblink.sh" with contains:

#---------------------------------------------------------------------------------
# reserve resources export gpio_4
echo "4" > /sys/class/gpio/export
# make gpio_4 to ouput
echo "out" > /sys/class/gpio/gpio4/direction
# set gpio_4 value to logical '1'
echo "1" > /sys/class/gpio/gpio4/value
# wait 2 seconds
sleep 2s
# set gpio_4 value to logical '0'
echo "0" > /sys/class/gpio/gpio4/value
# wait 2 seconds
sleep 2s
# set gpio_4 value to logical '1'
echo "1" > /sys/class/gpio/gpio4/value
# wait 2 seconds
sleep 2s
# set gpio_4 value to logical '0'
echo "0" > /sys/class/gpio/gpio4/value
# wait 2 seconds
sleep 2s
# release reserved resources and unexport gpio_4
echo "4" > /sys/class/gpio/unexport
#---------------------------------------------------------------------------------

Save and close file.

Make file to executable:

chmod +x ledblink.sh

Execute shell script:
./ledblink.sh