Learning   Examples | Foundations | Hacking | Links

Examples > Joystick

Joystick Mouse Control

Using the Mouse library, you can controls a computer's onscreen cursor with an Arduino Leonardo, Micro, or Due. This particular example uses a pushbutton to turn on and off mouse control with a joystick.

Cursor movement from the Arduino is always relative. So every time the analog input is read, the cursor's position is updated relative to it's current position.

Two analog inputs ranging from 0 to 1023 are translated to ranges of -12 to 12. The sketch assumes that the joystick resting values are around the middle of the range, but that they vary within a threshold.

The pushbutton allows you to toggle mouse control on and off. A status LED connected to pin 5 lights when the Arduino is controlling the mouse.

NB: When you use the Mouse.move() command, the Arduino takes over your computer's cursor! To insure you don't lose control of your computer while running a sketch with this function, make sure to set up a controller before you call Mouse.move(). This sketch includes a pushbutton to toggle the mouse control state, so you can turn on and off mouse control.

Hardware Required

  • Arduino Leonardo, Micro, or Due board
  • 2 axis joystick
  • momentary pushbutton
  • One 10-kilohm resistor (if needed)

Software Required

  • none

Circuit

Connect your Leonardo board to your computer with a micro-USB cable. The pushbutton is connected to pin 6. If you're using a part like the Joystick shield pictured below, you may not need a pulldown resistor. The x-axis on the joystick is connected to analog in 0, the y-axis is on analog in 1.

click the images to enlarge

image developed using Fritzing. For more circuit examples, see the Fritzing project page

Code

/*
  JoystickMouseControl
 
 Controls the mouse from a joystick on an Arduino Leonardo or Micro.
 Uses a pushbutton to turn on and off mouse control, and
 a second pushbutton to click the left mouse button
 
 Hardware:
 * 2-axis joystick connected to pins A0 and A1
 * pushbuttons connected to pin D2 and D3
 
 The mouse movement is always relative. This sketch reads
 two analog inputs that range from 0 to 1023 (or less on either end)
 and translates them into ranges of -6 to 6.
 The sketch assumes that the joystick resting values are around the
 middle of the range, but that they vary within a threshold.
 
 WARNING:  When you use the Mouse.move() command, the Arduino takes
 over your mouse!  Make sure you have control before you use the command.
 This sketch includes a pushbutton to toggle the mouse control state, so
 you can turn on and off mouse control.
 
 created 15 Sept 2011
 updated 28 Mar 2012
 by Tom Igoe
 
 this code is in the public domain
 
 */


// set pin numbers for switch, joystick axes, and LED:
const int switchPin = 2;      // switch to turn on and off mouse control
const int mouseButton = 3;    // input pin for the mouse pushButton
const int xAxis = A0;         // joystick X axis  
const int yAxis = A1;         // joystick Y axis
const int ledPin = 5;         // Mouse control LED

// parameters for reading the joystick:
int range = 12;               // output range of X or Y movement
int responseDelay = 5;        // response delay of the mouse, in ms
int threshold = range/4;      // resting threshold
int center = range/2;         // resting position value

boolean mouseIsActive = false;    // whether or not to control the mouse
int lastSwitchState = LOW;        // previous switch state

void setup() {
  pinMode(switchPin, INPUT);       // the switch pin
  pinMode(ledPin, OUTPUT);         // the LED pin  
 // take control of the mouse:
  Mouse.begin();
}

void loop() {
  // read the switch:
  int switchState = digitalRead(switchPin);
  // if it's changed and it's high, toggle the mouse state:
  if (switchState != lastSwitchState) {
    if (switchState == HIGH) {
      mouseIsActive = !mouseIsActive;
      // turn on LED to indicate mouse state:
      digitalWrite(ledPin, mouseIsActive);
    }
  }
  // save switch state for next comparison:
  lastSwitchState = switchState;

  // read and scale the two axes:
  int xReading = readAxis(A0);
  int yReading = readAxis(A1);

  // if the mouse control state is active, move the mouse:
  if (mouseIsActive) {
    Mouse.move(xReading, yReading, 0);
  }  

  // read the mouse button and click or not click:
  // if the mouse button is pressed:
  if (digitalRead(mouseButton) == HIGH) {
    // if the mouse is not pressed, press it:
    if (!Mouse.isPressed(MOUSE_LEFT)) {
      Mouse.press(MOUSE_LEFT);
    }
  }
  // else the mouse button is not pressed:
  else {
    // if the mouse is pressed, release it:
    if (Mouse.isPressed(MOUSE_LEFT)) {
      Mouse.release(MOUSE_LEFT);
    }
  }

  delay(responseDelay);
}

/*
  reads an axis (0 or 1 for x or y) and scales the
 analog input range to a range from 0 to <range>
 */


int readAxis(int thisAxis) {
  // read the analog input:
  int reading = analogRead(thisAxis);

  // map the reading from the analog input range to the output range:
  reading = map(reading, 0, 1023, 0, range);

  // if the output reading is outside from the
  // rest position threshold,  use it:
  int distance = reading - center;

  if (abs(distance) < threshold) {
    distance = 0;
  }

  // return the distance for this axis:
  return distance;
}

See Also

Share