ddr_pad.ino

#include <Joystick.h>

Joystick_ Joystick(JOYSTICK_DEFAULT_REPORT_ID,JOYSTICK_TYPE_GAMEPAD, //Set up for joystick
  1, 0,                  // button counter values
  true, true, false,     // axes (x,y,z)
  false, false, false,   // no Rx, Ry, or Rz (rotation around respective axis)
  false, false,          // no rudder or throttle
  false, false, false);  // no accelerator, brake, or steering

void setup() {
// initialize button pins
  pinMode(2, INPUT_PULLUP); // pin 2 = UP
  pinMode(3, INPUT_PULLUP); // pin 3 = RIGHT
  pinMode(4, INPUT_PULLUP); // pin 4 = DOWN
  pinMode(5, INPUT_PULLUP); // pin 5 = LEFT

  Joystick.begin();
  Joystick.setXAxisRange(-1, 1);
  Joystick.setYAxisRange(-1, 1);
}

// button state array
int lastButtonState[4] = {0,0,0,0};

void loop() {
  // read in pin values
  for (int index = 0; index < 4; index++){
    int currentButtonState = !digitalRead(index + 2);
    if (currentButtonState != lastButtonState[index]){
      switch (index) {
        case 0: // UP
          if (currentButtonState == 1) {
            Joystick.setYAxis(-1);
          } else {
            Joystick.setYAxis(0);
          }
          break;
        case 1: // RIGHT
          if (currentButtonState == 1) {
            Joystick.setXAxis(1);
          } else {
            Joystick.setXAxis(0);
          }
          break;
        case 2: // DOWN
          if (currentButtonState == 1) {
            Joystick.setYAxis(1);
          } else {
            Joystick.setYAxis(0);
          }
          break;
        case 3: // LEFT
          if (currentButtonState == 1) {
            Joystick.setXAxis(-1);
          } else {
            Joystick.setXAxis(0);
          }
          break;
      }
      lastButtonState[index] = currentButtonState;
    }
  }
  delay(10);
}