One of the simplest way to interact with the GoPiGo (a nice little robotics platform for the Raspberry Pi) is to use the two LED's in the front of it .
With a very simple command, you can make the GoPiGo give signals or just do a simple blink.
Step 1: What You Need
Step 2: Running the Example
Just power on the GoPiGo and go to the LED example folder:
cd GoPiGo/Software/Python/Examples/LED\ Blink
and run the example:
sudo python led_blink.py
As soon as the code is run, you can see the LED's blinking in the Front of the GoPiGo.
You can use this anyway you like in your own robotics Projects with the GoPiGo.