Arduino - Joystick

Hardware Required

Or you can buy the following sensor kits:

About Joystick Sensor

You probably see the Joystick somewhere such as a game controller, toy controller, or even a big real machine such as an excavator controller.

The joystick is composed of two potentiometers square with each other, and one push button. Therefore, it provides the following outputs:

• An analog value (from 0 to 1023) corresponding to the horizontal position (called X-coordinate)
• An analog value (from 0 to 1023) corresponding to the vertical position (called Y-coordinate)
• A digital value of a pushbutton (HIGH or LOW)

The combination of two analog values can create 2-D coordinates with the center are values when the joystick is in the rest position. The real direction of the coordinates can be identified simply when you run a test code (in the next part).

Some applications may use all three outputs, some applications may use some of three outputs.

Pinout

A Joystick has 5 pins:

• GND pin: needs to be connected to GND (0V)
• VCC pin: needs to be connected to VCC (5V)
• VRX pin: outputs an analog value corresponding to the horizontal position (called X-coordinate).
• VRY pin: outputs an analog value corresponding to the vertical position (called Y-coordinate).
• SW pin: is the output from the pushbutton inside the joystick. It’s normally open. If we use a pull-up resistor in this pin, the SW pin will be HIGH when it is not pressed, and LOW when it is pressed.

How It Works

• When you push the joystick's thump to left/right, the voltage in the VRX pin is changed, The voltage range is from 0 to 5V (0 at left and 5v at right). The voltage value is in proportion to the position of the thump ⇒ The reading value on Arduino's analog pin is from 0 to 1023
• When you push the joystick's thump to up/down, the voltage in the VRY pin is changed, The voltage range is from 0 to 5V (0 at up and 5v at down). The voltage value is in proportion to the position of the thump ⇒ The reading value on Arduino's analog pin is from 0 to 1023
• When you push the joystick's thump to any direction, the voltage in both VRX and VRY pins is changed in proportion to the projection of position on each axis
• When you push the joystick's thump from top to bottom, the pushbutton inside the joystick is closed, If we use a pull-up resistor in the SW pin, the output from SW pin will change from 5V to 0V ⇒ The reading value on Arduino's digital pin is changed from HIGH to LOW

Wiring Diagram

This image is created using Fritzing. Click to enlarge image

How To Program For Joystick

The joystick has two parts: analog (X, Y axis) and digital (pushbutton)

• For the analog parts (X, Y axis), it just need to read the value from analog input pin by using analogRead() function.

• For the digital part (pushbutton): it is a button. The most simple and convenient way is to use ezButton library. This library supports debounce for buttons and also enables an internal pull-up resistor. You can see more about button in Arduino - Button tutorial. The code will be presented in the next session in this tutorial.

After reading the values from analog pins, we may need to convert them to some controllable values. The next part will provide the example codes for this.

Arduino Code

This section will provide the following Arduino example codes:

• Example code: reads analog values from joystick
• Example code: reads analog values and reads the button state from joystick
• Example code: converts analog value to MOVE_LEFT, MOVE_RIGHT, MOVE_UP, MOVE_DOWN commands
• Example code: converts analog values to angles to control two servo motors (e.g. in pan-tilt camera)

Reads analog values from joystick

Quick Steps

• Copy the above code and open with Arduino IDE
• Click Upload button on Arduino IDE to upload code to Arduino
• Push the joystick's thump maximally to the limit, and then rotate it in a circle (clockwise or anti-clockwise)
• See the result on Serial Monitor.

• While rotating the joystick' thump, keep watching the Serial Monitor
• If the X value is 0, mark or memorize the current position as left ⇒ the opposite direction the right
• If the Y value is 0, mark or memorize the current position as up ⇒ the opposite direction the down

Reads analog values and reads the button state from a joystick


/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-joystick */ #include <ezButton.h> #define VRX_PIN A0 // Arduino pin connected to VRX pin #define VRY_PIN A1 // Arduino pin connected to VRY pin #define SW_PIN 2 // Arduino pin connected to SW pin ezButton button(SW_PIN); int xValue = 0; // To store value of the X axis int yValue = 0; // To store value of the Y axis int bValue = 0; // To store value of the button void setup() { Serial.begin(9600) ; button.setDebounceTime(50); // set debounce time to 50 milliseconds } void loop() { button.loop(); // MUST call the loop() function first // read analog X and Y analog values xValue = analogRead(VRX_PIN); yValue = analogRead(VRY_PIN); // Read the button value bValue = button.getState(); if (button.isPressed()) { Serial.println("The button is pressed"); // TODO do something here } if (button.isReleased()) { Serial.println("The button is released"); // TODO do something here } // print data to Serial Monitor on Arduino IDE Serial.print("x = "); Serial.print(xValue); Serial.print(", y = "); Serial.print(yValue); Serial.print(" : button = "); Serial.println(bValue); }

Quick Steps

• Navigate to the Libraries icon on the left bar of the Arduino IDE.
• Search “ezButton”, then find the button library by ArduinoGetStarted.com
• Click Install button to install ezButton library.

• Copy the above code and open with Arduino IDE
• Click Upload button on Arduino IDE to upload code to Arduino
• Push the thump of the joystick to left/right/up/down
• Push the thump of the joystick from the top
• See the result on Serial Monitor.
COM6
Send
Autoscroll Show timestamp
Clear output
9600 baud  
Newline  

Converts analog value to MOVE LEFT/RIGHT/UP/DOWN commands


/* * Created by ArduinoGetStarted.com * * This example code is in the public domain * * Tutorial page: https://arduinogetstarted.com/tutorials/arduino-joystick */ #define VRX_PIN A0 // Arduino pin connected to VRX pin #define VRY_PIN A1 // Arduino pin connected to VRY pin #define LEFT_THRESHOLD 400 #define RIGHT_THRESHOLD 800 #define UP_THRESHOLD 400 #define DOWN_THRESHOLD 800 #define COMMAND_NO 0x00 #define COMMAND_LEFT 0x01 #define COMMAND_RIGHT 0x02 #define COMMAND_UP 0x04 #define COMMAND_DOWN 0x08 int xValue = 0 ; // To store value of the X axis int yValue = 0 ; // To store value of the Y axis int command = COMMAND_NO; void setup() { Serial.begin(9600) ; } void loop() { // read analog X and Y analog values xValue = analogRead(VRX_PIN); yValue = analogRead(VRY_PIN); // converts the analog value to commands // reset commands command = COMMAND_NO; // check left/right commands if (xValue < LEFT_THRESHOLD) command = command | COMMAND_LEFT; else if (xValue > RIGHT_THRESHOLD) command = command | COMMAND_RIGHT; // check up/down commands if (yValue < UP_THRESHOLD) command = command | COMMAND_UP; else if (yValue > DOWN_THRESHOLD) command = command | COMMAND_DOWN; // NOTE: AT A TIME, THERE MAY BE NO COMMAND, ONE COMMAND OR TWO COMMANDS // print command to serial and process command if (command & COMMAND_LEFT) { Serial.println("COMMAND LEFT"); // TODO: add your task here } if (command & COMMAND_RIGHT) { Serial.println("COMMAND RIGHT"); // TODO: add your task here } if (command & COMMAND_UP) { Serial.println("COMMAND UP"); // TODO: add your task here } if (command & COMMAND_DOWN) { Serial.println("COMMAND DOWN"); // TODO: add your task here } }

Quick Steps

• Copy the above code and open with Arduino IDE
• Click Upload button on Arduino IDE to upload code to Arduino
• Push the thump of joystick to left/right/up/down or any direction
• See the result on Serial Monitor.
COM6
Send
Autoscroll Show timestamp
Clear output
9600 baud  
Newline  

※ NOTE THAT:

At a time, there may be no command, one command or two commands (e.g. UP and LEFT at the same time)

Converts analog values to angles to control two servo motors

The detail is presented on Arduino - Joystick controls Servo Motor tutorial

Video Tutorial

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Function References

• pinMode()
• digitalRead()
• analogRead()
• Serial

The Best Arduino Starter Kit

• See the best Arduino kit for beginner

See Also

• Arduino - Joystick - Servo Motor