Arduino Day 9: Simon(ish) Game

const int BuzzPin = 5;
const int BuzzDuration = 100; 

int ButtonPins[] = { 3, 7 };
int Tones[] = { 2000, 3000, 1000 };
int LedPins[] = { 4, 6, 5 };

void setup() {
  for(int i = 0; i < 3; i++){
    pinMode(LedPins[i], OUTPUT);    
    Ding(i);  // boot test
  }
}

// our main loop will look at the game state to 
// figure out what to do
enum GameState {
  InsertCoin, // waiting for player to start game
  Teach,      // buzzing a random sequence, increasing by one element each time
  Test,       // checking user-entered sequence
  Boo         // you've lost
};

// start in the finished state because that sets up some things for us
GameState State = InsertCoin;

// pick a seed value for the random number generator
// we'll reuse this each time the sequence is played so we get the same sequence
int Seed;

// keeps track of how many tones there are in the sequence
int Taps;

void loop() {
  switch(State){
    case InsertCoin:
      // light up both sides to suggest the user tap one to start
      digitalWrite(LedPins[0], HIGH); 
      digitalWrite(LedPins[1], HIGH); 
      
      GetPress();

      // let's go!
      Taps = 0;
      Seed = analogRead(0); // pick a new sequence seed

      digitalWrite(LedPins[0], LOW); 
      digitalWrite(LedPins[1], LOW); 

      State = Teach;
      delay(1000);
      
      break;
    
    case Teach:
      // add one to the sequence and play what we have so far
      Taps++;

      randomSeed(Seed);
      for(int i = 0; i < Taps; i++){
        Ding(random(0,2));
        delay(100);
      }

      State = Test;
      break;
      
    case Test:
      randomSeed(Seed);
      for(int i = 0; i < Taps; i++){
        int Tap = GetPress();
        int ExpectedTap = random(0,2);
        if(Tap != ExpectedTap){
          // you fail
          State = Boo; 
          return;
        }
      }      
      
      // if we make it through the entire test, good job!
      // add another note
      State = Teach;
      delay(1000);
      break;
      
    case Boo:
      for(int i = 0; i<5; i++){
        Ding(2);
      }
  
      State = InsertCoin;
      delay(1000);
      break;
  }
}

// this function blocks until a button is pressed
int GetPress(){
  int P1; int P2;
  
  do {
    P1 = digitalRead(P1ButtonPin);
    P2 = digitalRead(P2ButtonPin);

  } while(!(P1 || P2));
  
  int Key = P1? 0 : 1;
  Ding(Key);

  return Key;  
}

void Ding(int light){
  // e.g. 1 / 2048Hz = 488uS, or 244uS high and 244uS low
  // to create 50% duty cycle
  // http://www.arduino.cc/cgi-bin/yabb2/YaBB.pl?num=1231194692
  int Osc = 1000000 / Tones[light] / 2; // in microseconds
  
  // compute the number of iterations needed to hold
  // the nfote the desired duration
  int Iterations = Tones[light] * ((float)200 / 1000);
  
  // light on
  digitalWrite(LedPins[light], HIGH);
  
  // play tone
  for (long i = 0; i < Iterations; i++ )
  {
      digitalWrite(BuzzPin, HIGH);
      delayMicroseconds(Osc);
      digitalWrite(BuzzPin, LOW);
      delayMicroseconds(Osc);
  }  
  
  // light off
  digitalWrite(LedPins[light], LOW);
}