Joystick Module

../_images/19_joystick.png

Introduction

A joystick module is a device that can measure the movement of a knob in two directions: horizontal (X-axis) and vertical (Y-axis). A joystick module can be used to control various things such as games, robots, cameras, etc.

Principle

Joystick operates based on the resistance change of two potentiometers (usually 10-kilo ohms). By changing resistance in x and y directions, Arduino receives varying voltages which are interpreted to x and y coordinates. The processor needs an ADC unit to change the joystick’s analog values into digital values and perform necessary processing.

Arduino boards have six 10-bits ADC channels. It means the Arduino’s reference voltage (5 volts) is divided to 1024 segments. When joystick moves along the x-axis, the ADC value rises from 0 to 1023, with the value 512 in the middle. The image below displays the ADC approximate value based on the joystick position.

../_images/19_joystick_xy.png

Usage

Hardware components

  • Arduino Uno R4 or R3 board * 1

  • Joystick Module * 1

  • Jumper Wires

Circuit Assembly

../_images/19_joystick_module_circuit.png

Code



Code explanation

  1. Setting up the joystick pins. Here, we define which analog pins the X and Y axes of the joystick are connected to.

    const int xPin = A0;
    const int yPin = A1;
    
  2. Initialization in the setup() function. This section sets up the serial communication, allowing us to send and receive messages from the Arduino through the serial monitor.

    void setup() {
      Serial.begin(9600);
    }
    
  3. Reading the joystick values in the loop() function. Continuously, the Arduino reads the X and Y values from the joystick and prints them to the serial monitor. There’s a short delay after each print to make the readings more readable and to avoid overwhelming the serial monitor.

    void loop() {
      Serial.print("X: ");
      Serial.print(analogRead(xPin));
      Serial.print(" | Y: ");
      Serial.println(analogRead(yPin));
      delay(50);
    }
    

Additional Ideas

  • Use the joystick values to control a servo motor, making it move in response to joystick movements.