42 Bots

In one of my rather frequent eBay visits, I came across a nifty little joystick module, much similar to the analog thumb-stick on the PlayStation 2 controllers. The module is very easy to use with an Arduino uno and only costs a few dollars. Several different versions are available from eBay, Adafruit, Sparkfun and other vendors, but they essentially work the same.

Overview

The module has 5 pins: Vcc, Ground, X, Y, Key. Note that the labels on yours may be slightly different, depending on where you got the module from. The thumbstick is analog and should provide more accurate readings than simple ‘directional’ joysticks tat use some forms of buttons, or mechanical switches. Additionally, you can press the joystick down (rather hard on mine) to activate a ‘press to select’ push-button.

We have to use analog Arduino pins to read the data from the X/Y pins, and a digital pin to read the button. The Key pin is connected to ground, when the joystick is pressed down, and is floating otherwise. To get stable readings from the Key /Select pin, it needs to be connected to Vcc via a pull-up resistor. The built in resistors on the Arduino digital pins can be used. For a tutorial on how to activate the pull-up resistors for Arduino pins, configured as inputs, see this..

Arduino Joystick Module Demo

Wiring Diagram

Sample Code

int xPin = A1;
int yPin = A0;
int buttonPin = 2;

int xPosition = 0;
int yPosition = 0;
int buttonState = 0;

void setup() {
  // initialize serial communications at 9600 bps:
  Serial.begin(9600); 
  
  pinMode(xPin, INPUT);
  pinMode(yPin, INPUT);

  //activate pull-up resistor on the push-button pin
  pinMode(buttonPin, INPUT_PULLUP); 
  
  // For versions prior to Arduino 1.0.1
  // pinMode(buttonPin, INPUT);
  // digitalWrite(buttonPin, HIGH);
  
}

void loop() {
  xPosition = analogRead(xPin);
  yPosition = analogRead(yPin);
  buttonState = digitalRead(buttonPin);
  
  Serial.print("X: ");
  Serial.print(xPosition);
  Serial.print(" | Y: ");
  Serial.print(yPosition);
  Serial.print(" | Button: ");
  Serial.println(buttonState);

  delay(100); // add some delay between reads
}