Two way serial communication with raspberry Pi (radio project)

Projects Interfacing w/ Software on the Computer
22

Problem solved:

I skipped Arduino Uno and work with Raspberry's gpio pins only. No serial communication needed any more ... XD

The following declares gpio pin 7 to be an input pin:

echo "7" > /sys/class/gpio/export
echo "in" > /sys/class/gpio/gpio7/direction

Whenever I press a button, variable BUTTON gets value 1, otherwise 0

BUTTON=$(cat /sys/class/gpio/gpio7/value)

So after booting my radio starts playing with station 1; pressing the button produces a switch to the next station.
When the end of the list is reached, we start again with station 1.