在bash中控制raspberry pi的GPIO

http://elinux.org/RPi_Low-level_peripherals

# Set up GPIO 4 and set to output
echo "4" > /sys/class/gpio/export
echo "out" > /sys/class/gpio/gpio4/direction
 
# Set up GPIO 7 and set to input
echo "7" > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio7/direction
 
# Write output
echo "1" > /sys/class/gpio/gpio4/value
 
# Read from input
cat /sys/class/gpio/gpio7/value 
 
# Clean up
echo "4" > /sys/class/gpio/unexport
echo "7" > /sys/class/gpio/unexport