Optional Arduino Lab: Joystick

Goal: Create a project using the analog joystick.

 

Circuit Setup

• Materials
  • 1x Arduino
  • 1x Joystick
  • Other components
• Setup
  • Joystick
    • GND - Ground connection
    • +5V - 5V connection
    • VRx - analog voltage value between 0V and 5V giving you the relative x position
    • VRy - analog voltage value between 0V and 5V giving you the relative x position
    • SW - pushbutton switch, click in to press

 

Lab Instructions

• Project must use an analog joystick to control some other component. Here are some ideas:
  • Use it to control the brightness of an LED.
  • Use it to color mix an RGB LED.
  • Use it to control which LED in a sequence of LEDs is lit up.
• Use analogRead() to determine the x and y position of the joystick.
  • Remember: analogRead() returns a value between 0-1023
  • The midpoint is ~512.
• To control the brightness of the LED, we will use a new function called analogWrite().
  • A technique for getting pseudo-analog results with digital means. Does not write a true analog value.
  • Digital control is used to create a square wave (signal switched between on & off).
  • Reduces average power by pulsing a voltage at a very fast rate. Used to control intensity like the speed of motors or brightness of LEDs.
  • Use analogRead() to read a value from the joystick and analogWrite() to write a value to an LED.
  • analogWrite(pin, value) - sends a PWM wave only works on pins with tilde ~ (pins 3, 5, 6, 9, 10, 11)
    • pin: the Arduino pin to write to.
    • value: the duty cycle: between 0 (always off) and 255 (always on).

• Stretch Goal: Use digitalRead() to determine whether or not the switch is pressed.
  • Configure pin like so: pinMode(SW, INPUT_PULLUP)
  • Switch is pressed when digitalRead(SW) == LOW