Sweaty palms…

// Luv-o-meter
// simple at first, just checking for the buttons and switching on the LED as necessary

int switch1 = 2;
int switch2 = 3;

int led1Pin = 5;
int led2Pin = 6;

int ledMeter[] = {
  8,9,10,11,12};

int gsrPin = 0; // analog pin
// the GSR sensor that I'm using reports fluxuations +10 when the MacBook is connected to AC power

// for comparing the start and end values of the GSR
int readGSR = 0;
int gsrBegin = 0;
int gsrEnd = 0;
int clickCount = 0; // counter for the button presses

int gameState = 0; // store the current state of the sketch

int gameScore = 0; // to tally the final score

int buttonPressed = 0;

// various timing vars
long timer = 0;
long gameDur = 10 * 1000; // the length of the game
long thinkDur = 3 * 1000; // the time for the game to "think" about the results
long resultsDur = 5 * 1000; // the duration of the results display before the sketch results
long timeout = 5 * 1000; // the timeout to return to the initial state
long gsrSmoothDur = 3 * 1000; // average the GSR readings at the beginning and end

void setup() {
  pinMode(switch1,INPUT);
  pinMode(switch2,INPUT);
  pinMode(led1Pin,OUTPUT);
  pinMode(led2Pin,OUTPUT);

  for(int i=0;i<5;i++){
    pinMode(ledMeter[i],OUTPUT);
  }

  Serial.begin(9600);
}

void loop() {
  int read1 = digitalRead(switch1);
  int read2 = digitalRead(switch2);

  // readGSR = analogRead(gsrPin);
  // Serial.println(readGSR);

  /*
  Serial.print("button 1: ");
   Serial.println(read1);
   Serial.print("button 2: ");
   Serial.println(read2);
   */
  switch(gameState){
  case 0: // waiting to start the game

    // begin if either button is pressed:
    if(read1 == LOW || read2 == LOW) {
      gameState = 1; // set the approriate game state
      clickCount = 0; // rest the counter variable

      // turn on the button LEDs to acknowledge the press:
      digitalWrite(led1Pin,HIGH);
      digitalWrite(led2Pin,HIGH);

      countDown(); // display the starting sequence

      // turn off the button LEDs to begin:
      digitalWrite(led1Pin,LOW);
      digitalWrite(led2Pin,LOW);

      timer = millis(); // reset the timer

      // read the start value of the GSR.
      // need to do this better to smooth the results:
      gsrBegin = analogRead(gsrPin);
    }
    break;

  case 1: // playing the game
    if(millis() - timer > gameDur){ // the game is over.
      digitalWrite(led1Pin,LOW);
      digitalWrite(led2Pin,LOW);

      // need to do this better. need to smooth the GSR values
      // now being done at the end of the game state, using a timer.
      //gsrEnd = analogRead(gsrPin);

      gameState = 2; // change the game state to calculate the results
      timer = millis();
    }
    else {
      // do the game stuff:
      // instant feedback - illuminate the button LEDs:
      if(read1 == LOW || read2 == LOW) {
        // ensure that one press / release is counted:
        if(!buttonPressed){
          digitalWrite(led1Pin,1-read1);
          digitalWrite(led2Pin,1-read2);

          clickCount++;
          buttonPressed = 1;
        }
      }
      else {
        digitalWrite(led1Pin,LOW);
        digitalWrite(led2Pin,LOW);
        buttonPressed = 0;
      }

      // use the meter as a game progress:
      int progress = (int) map(millis()-timer,0,gameDur,0,5);
      levelMeterNoDelay(progress);

      readGSR = analogRead(gsrPin);

      //smooth the beginning of the GSR:
      if(millis()-timer < gsrSmoothDur) {
        gsrBegin = (gsrBegin+readGSR)/2;
      }

      //smooth the end GSR readings:
      if(millis()-timer+gsrSmoothDur > gameDur){
        gsrEnd = (gsrEnd+readGSR)/2;
      }

      // send data only when asked for data:
      if (Serial.available() > 0) {
        // read the incoming byte:
        int incomingByte = Serial.read();

        // wait for the 'A' char
        if(incomingByte == 65){
          // return the GSR:
          Serial.println(readGSR);
        }
      }
    }
    break;

  case 2: // display the results of the game
    gameScore = calculateScore();
    displayThink(); // for testing the circuit
    levelMeter(gameScore);
    gameState = 3;
    timer = millis();
    break;

  case 3: // the game has ended, hold on the score display
    if(millis() - timer > resultsDur) {
      gameState = 0;
      meterOff();
      timer = millis();
    }
    break;

  }

}

void blinkOn(int led) {
  digitalWrite(led,HIGH);
  delay(100);
  digitalWrite(led,LOW);
  delay(50);
  digitalWrite(led,HIGH);
  delay(100);
}

void blinkOff(int led) {
  digitalWrite(led,LOW);
  delay(50);
  digitalWrite(led,HIGH);
  delay(100);
  digitalWrite(led,LOW);
  delay(50);
}

void displayThink() {
  // run some kind of blinking rhythm
  // cycle through the array of LEDs
  // assuming that the array is 5 units long
  for(int j=0;j<2;j++){
    for (int i =0;i<5;i++){
      blinkOn(ledMeter[i]);
      delay(10);
    }

    for (int i =0;i<5;i++){
      blinkOff(ledMeter[i]);
      delay(10);
    }
    delay(5);
  }

}

void levelMeter(int units){
  units = constrain(units,0,5);

  for (int i =0;i<units;i++){
    blinkOn(ledMeter[i]);
    delay(50);
  }
}

void levelMeterNoDelay(int units){
  units = constrain(units,0,5);

  meterOff();
  for (int i =0;i<units;i++){
    digitalWrite(ledMeter[i],HIGH);
  }
}

void meterOff() {
  // turn them all off, immediately
  for (int i =0;i<5;i++){
    digitalWrite(ledMeter[i],LOW);
  }
}

void meterOn() {
  // turn them all on, immediately
  for (int i =0;i<5;i++){
    digitalWrite(ledMeter[i],HIGH);
  }
}

void meterBlink() {
  meterOff();
  delay(50);
  meterOn();
  delay(50);
}

int calculateScore() {
  // calculate the score based on the number of presses and the GSR difference:
  int theScore = 0;

  // simple for the initial test, just work out a range based on the number of clicks
  // give a score of at least 1
  // theScore = (int) map(clickCount,0,100,1,5);

  // using GSR:
  int gsrDiff = gsrEnd - gsrBegin; // assuming that the GSR will increase over the test
  theScore = (int) map(gsrDiff,0,clickCount,1,5);
  if(theScore < 1) theScore = 1;

  Serial.print("GSR begin: ");
  Serial.println(gsrBegin);
  Serial.print("GSR end: ");
  Serial.println(gsrEnd);
  Serial.print("GSR diff: ");
  Serial.println(gsrDiff);
  Serial.print("Click count: ");
  Serial.println(clickCount);
  Serial.print("Score: ");
  Serial.println(theScore);
  Serial.println("---");

  return theScore;
}

void countDown() {
  meterBlink();
  delay(100);
  meterBlink();
  delay(100);
  meterBlink();
  delay(100);

  // countdown to the start
  for (int i=4;i>=0;i--){
    blinkOff(ledMeter[i]);
    delay(50);
  }
}