Objective: In this activity you'll learn how to use the left-right action of a joystick to turn on a red LED when the joystick is pushed to the left and a green LED when it's pushed to the right (or vice versa, depending on how you have the joystick oriented).

The Code:

1. Set up digital pins 12 and 13 (the green and red LEDs) for output, and digital pin 2 (the joystick's B pin) and analog pin A1 (the joystick's X pin) for input. 
2. Start a loop that reads the joystick's B pin until it gets a nonzero "high" or "1" signal, indicating that the joystick button was pushed. 
3. Inside the loop use two conditional "if-else" statements to check the state of the joystick's X value:
   1. Get the current X value from the joystick. The value ranges from 0 (joystick pushed completely left) to 1023 (pushed completely right). The middle "neutral" value is 512, although the joystick calibration may be slightly off, so that the neutral value is around but not exactly equal to 512.
   2. Use an "if-else" statement to check if the X value is greater than 712. If so, turn on the green LED. If not, make sure the green LED is off.
   3. Use another "if-else" statement to check if the X value is less than 312. If so, turn on the red LED. If not, make sure the red LED is off.
   4. Note: The 712 and 312 values are 512 plus or minus 200, but other values could be used.

Connections (see diagram below):
The joystick has five pins: Y, X, B, VCC, and GND.

1. Using male-to-female wires, connect the VCC and GND pins to the 5V and one of the GND pins, respectively, in the Power section of the Arduino.
2. Connect the B (button) pin to digital pin 2 on the Arduino.
3. Connect the X pin to analog pin A1. For this activity we don't need the Y pin (the green wire).
4. For the LED module (not shown on the diagram), plug in its B, G, and R pins to digital pins 11, 12, and 13, respectively, on the Arduino, with the module's "-" pin going in the GND pin.