"Galaga" With Arduino - Cayla Kennedy and Ananya Tandel

This project is an improvement of a prior project where one of our group members created Galaga using analog sensors, LED strips, and an Arduino board. The project serves to make a meaningful interaction by encouraging people to make noise and truly play. Unlike the arcade version of Galaga, this version is much smaller and uses LED strips to create a pixel grid, and the user controls the game with a knob and sound, whether that sound comes from their own voice or general noise level in the room.

As the LED strips offer a very limited range of graphics, the game is visually represented as simply as possible. The player's ship is represented by one purple pixel on the bottom row of the screen, the beam shot by the player's ship is represented by a line of blue pixels, and the attacking ship is represented by a single red pixel.

• Arduino Nano Every
• Breadboard
• 5 Neopixel LED strips
• Jumper cables/wires
• Pull-Down Resistors
• 1 Button
• 1 Microphone
• 1 Radial Potentiometer

For ease of assembly, a breadboard was used to make electrical connections between the components. Since breadboards tend to not be the most reliable when it comes to maintaining wired connections, hot glue was used in order to keep each wire in place, and insulate between wires in the case where it is possible for movement and touching. This project utilized mostly stranded wires, as they fit into the compact design of the enclosure far better than solid core wires did. The schematic above shows the general circuitry, with each Neopixel strip (not all are shown) being wired the same, just connected to different pins.

Coding for this project was completed in the language c++ in the Arduino IDE. The Adafruit Neopixel library is needed to properly operate the LED strips. The code is made up mostly of if-else statements, and has comments throughout which explain what each function does, and the code is as follows:

#include <Adafruit_NeoPixel.h>
#include <stdlib.h>
#ifdef __AVR__
  #include <avr/power.h>
#endif


#define ROW1PIN 21
#define ROW2PIN 3
#define ROW3PIN 4
#define ROW4PIN 5
#define ROW5PIN 6


//declare global variables (pin vals, etc)
  //initialize pins
  const int knobPin = A0;
  const int screamPin = A5;
  const int pausePin = 17;

  int baseSound = 0;
  int knobNum = 0;
  int screamNum = 0;
  int pauseNum = 0;
  int cnum = 0;
  int rnum = 0;
  int r1c = 0;
  int count = 0;
  int count2 = 0;
  int power = 0;
  int interval = 1000;
  bool noAttack = true;
  bool isPause = true;
  int range = 0;
  int i = 0;


  //neopixel strip
  Adafruit_NeoPixel row1 = Adafruit_NeoPixel(5, ROW1PIN, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row2 = Adafruit_NeoPixel(5, ROW2PIN, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row3 = Adafruit_NeoPixel(5, ROW3PIN, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row4 = Adafruit_NeoPixel(5, ROW4PIN, NEO_GRB + NEO_KHZ800);
  Adafruit_NeoPixel row5 = Adafruit_NeoPixel(5, ROW5PIN, NEO_GRB + NEO_KHZ800);

void setup() {


  // put your setup code here, to run once:
  Serial.begin(9600);
  pinMode(pausePin, INPUT);


  //initialize neopixels
  row1.begin();
  row1.show();


  row2.begin();
  row2.show();


  row3.begin();
  row3.show();


  row4.begin();
  row4.show();


  row5.begin();
  row5.show();


}


void loop() {


  //read numbers from the pins
  knobNum = analogRead(knobPin);
  screamNum = analogRead(screamPin);
  pauseNum = digitalRead(pausePin);


  //take baseline if this is the beginning of the game
  if (count == 0)
  {
    baseSound = takeSound();
  }


  //pause or unpause if the pause button is pressed
  if (pauseNum == 1)
  {
    pause();
  }

//prints to the serial monitor for testing purposes
  // Serial.print(baseSound);
  // Serial.print(',');
  // Serial.print(screamNum);
  // Serial.print(',');
  // Serial.print(knobNum);
  // Serial.print(',');
  // Serial.println(pauseNum);


  //only run if the game is not paused
  if (isPause == false)
    {


      count++;
      
      //bottom LED strip will be the "ship," controlled by the potentiometer
      steerShip();

      //attackers: in random columns
      if (noAttack == true)
      {
        generateEnemy();
      }
      
      //attackers: descend at a certain time interval
      if (count%interval == 0)
      {
        descend();
      }


      //shoot: light up the column the ship is in, controlled by sound sensor, higher sound reading = higher row
      if (screamNum != baseSound)
      {
        shoot();
      }
      
      if (screamNum <= baseSound)
      {
        row5.setPixelColor(r1c,0,0,0);
        row4.setPixelColor(r1c,0,0,0);
        row3.setPixelColor(r1c,0,0,0);
        row2.setPixelColor(r1c,0,0,0);
        row2.show();
        row3.show();
        row4.show();
        row5.show();
        power = 0;
        displayEnemy();
      }


      //on hit: green screen
      if (r1c == cnum && power >= rnum)
      {
        hit();
      }


      //on fail: red screen
      if (rnum == 1)
      {
        fail();
      }
    }
}


/*
    hit - triggered when an attacker ship is hit, lights up the screen green and resets the attacker
*/
void hit()
{
      for (int i = 0; i<5; i++)
    {
      row1.setPixelColor(i,0,255,0);
      row2.setPixelColor(i,0,255,0);
      row3.setPixelColor(i,0,255,0);
      row4.setPixelColor(i,0,255,0);
      row5.setPixelColor(i,0,255,0);
    }


    row1.show();
    row2.show();
    row3.show();
    row4.show();
    row5.show();


    delay(500);


    row1.clear();
    row2.clear();
    row3.clear();
    row4.clear();
    row5.clear();


    row1.show();
    row2.show();
    row3.show();
    row4.show();
    row5.show();


    rnum = 5;
    noAttack = true;
}


/*
    fail - triggered when the attacker ship reaches the first row, lights up the screen red and resets the attacker
*/
void fail()
{
    for (int i = 0; i<5; i++)
    {
      row1.setPixelColor(i,255,0,0);
      row2.setPixelColor(i,255,0,0);
      row3.setPixelColor(i,255,0,0);
      row4.setPixelColor(i,255,0,0);
      row5.setPixelColor(i,255,0,0);
    }


    row1.show();
    row2.show();
    row3.show();
    row4.show();
    row5.show();


    delay(500);


    row1.clear();
    row2.clear();
    row3.clear();
    row4.clear();
    row5.clear();


    noAttack = true;
    rnum = 5;
}


/*
    shoot - reads current sound level and shoots
*/
void shoot()
{
  if (screamNum > (baseSound + i))
  {
    row2.setPixelColor(r1c, 0,0,250);
    row2.show();
    power = 2;
  }
  //up to row 3
  if (screamNum > (baseSound + (2*i)))
  {
    row3.setPixelColor(r1c,0,0,250);
    row3.show();
    power = 3;
  }
  //up to row 4
  if (screamNum > (baseSound + (3*i)))
  {
    row4.setPixelColor(r1c,0,0,250);
    row4.show();
    power = 4;
  }
  //up to row 5
  if (screamNum > (baseSound + (4*i)))
  {
    row5.setPixelColor(r1c,0,0,250);
    row5.show();
    power = 5;
  }
}


/*
    generateEnemy - creates an enemy at a random column on the top row
*/
void generateEnemy()
{
  cnum = rand()%5;
  row5.setPixelColor(cnum, 250, 0, 0);
  row5.show();
  noAttack = false;
}


/*
    steerShip - moves the ship across the bottom row dependent on potentiometer reading
*/
void steerShip()
{
  row1.clear();
  row2.clear();
  row3.clear();
  row4.clear();
  row5.clear();
  //column 1
  if (knobNum >= 0 && knobNum < 204)
  {
    row1.setPixelColor(0, 250,50,50);
    r1c=0;
  }
  //column 2
  else if (knobNum >= 204 && knobNum < 408)
  {
    row1.setPixelColor(1, 250,50,50);
    r1c=1;
  }
  //column 3
  else if (knobNum >= 408 && knobNum < 612)
  {
    row1.setPixelColor(2, 250,50,50);
    r1c=2;
  }
  //column 4
  else if (knobNum >= 612 && knobNum < 816)
  {
    row1.setPixelColor(3, 250,50,50);
    r1c=3;
  }
  //column 5
  else
  {
    row1.setPixelColor(4, 250,50,50);
    r1c=4;
  }


  displayEnemy();
  row1.show();
  row2.show();
  row3.show();
  row4.show();
  row5.show();
}


/*
    descend - make enemy ship descend a row
*/
void descend()
{
    rnum--;
    cnum = rand()%5;
    //go down to row 4
    if (rnum == 4)
    {
      row5.clear();
      row4.setPixelColor(cnum, 255, 0, 0);
      row5.show();
      row4.show();
    }
    //go down to row 3
    else if (rnum == 3)
    {
      row4.clear();
      row3.setPixelColor(cnum, 255, 0, 0);
      row4.show();
      row3.show();
    }
    //go down to row 2 (closest to ship)
    else if (rnum == 2)
    {
      row3.clear();
      row2.setPixelColor(cnum, 255, 0, 0);
    }
}


/*
    pause - pause or unpause the game
*/
void pause(){
  if (isPause == true){
    isPause = false;
  }


  else
  {
    isPause = true;
  }


  count = 1;
}


/*
  displayEnemy - make sure enemy remains displayed when it is not defeated
*/
void displayEnemy(){
  if (rnum == 5){
      row5.setPixelColor(cnum, 255, 0, 0);
    row5.show();
  }
  else if (rnum == 4){
      row4.setPixelColor(cnum, 255, 0, 0);
    row4.show();
  }
  else if (rnum == 3){
      row3.setPixelColor(cnum, 255, 0, 0);
    row3.show();
  }
  else if (rnum == 2){
      row2.setPixelColor(cnum, 255, 0, 0);
    row2.show();
  }


}


/*
    takeSound - takes a baseline sound number and converts it to be a range read by the shoot function


    @return screamNum 
*/
int takeSound(){
  delay(1000);
  range = 1023 - screamNum;
  i = range /5;
  return screamNum;
}

Enclosure design was accomplished through laser-cutting wood pieces to make a pentagon-shaped wooden box that can be handheld. The template was made using MakerCase with a fixed inside diameter of 5.5 inches and fixed height of 2 inches. For making specific cutouts on the lid of the box, Adobe Illustrator was used to make precise cutouts for a button, a knob, a microphone, a USB cable, as well as an acrylic screen. The general box template and the cutouts were then lasered onto wood and wood glue was used to adhere all of the sides together, excluding the lid. Once all of the electronic components of Galaga were added, we glued the acrylic screen and the lid onto the sides of the box and the analog version of Galaga is fully functional.

The finished product was shown off in a showcase where people could experience the game. User testing like this was certainly a learning experience, as after not too long the cap on the potentiometer broke off, the button got stuck, and the acrylic “screen” got somewhat smudged. In the future and if anyone else were to make this project, we would recommend securing the components in the enclosure just a bit better so nothing breaks off.