Make an Arduino Memory Game

#define PLAYER_WAIT_TIME 2000 // The time allowed between button presses - 2s 

byte sequence[100];           // Storage for the light sequence
byte curLen = 0;              // Current length of the sequence
byte inputCount = 0;          // The number of times that the player has pressed a (correct) button in a given turn 
byte lastInput = 0;           // Last input from the player
byte expRd = 0;               // The LED that's suppose to be lit by the player
bool btnDwn = false;          // Used to check if a button is pressed
bool wait = false;            // Is the program waiting for the user to press a button
bool resetFlag = false;       // Used to indicate to the program that once the player lost

byte soundPin = 5;            // Speaker output

byte noPins = 4;              // Number of buttons/LEDs (While working on this, I was using only 2 LEDs)
                              // You could make the game harder by adding an additional LED/button/resistors combination.
byte pins[] = {2, 13, 10, 8}; // Button input pins and LED ouput pins - change these vaules if you wwant to connect yourbuttons to other pins
                              // The number of elements must match noPins below
                              
long inputTime = 0;           // Timer variable for the delay between user inputs

void setup() {
  delay(3000);                // This is to give me time to breathe after connection the arduino - can be removed if you want
  Serial.begin(9600);         // Start Serial monitor. This can be removed too as long as you remove all references to Serial below
  Reset();
}

///
/// Sets all the pins as either INPUT or OUTPUT based on the value of 'dir'
///
void setPinDirection(byte dir){
  for(byte i = 0; i < noPins; i++){
    pinMode(pins[i], dir); 
  }
}

//send the same value to all the LED pins
void writeAllPins(byte val){
  for(byte i = 0; i < noPins; i++){
    digitalWrite(pins[i], val); 
  }
}

//Makes a (very annoying :) beep sound
void beep(byte freq){
  analogWrite(soundPin, 2);
  delay(freq);
  analogWrite(soundPin, 0);
  delay(freq);
}

///
/// Flashes all the LEDs together
/// freq is the blink speed - small number -> fast | big number -> slow
///
void flash(short freq){
  setPinDirection(OUTPUT); /// We're activating the LEDS now
  for(int i = 0; i < 5; i++){
    writeAllPins(HIGH);
    beep(50);
    delay(freq);
    writeAllPins(LOW);
    delay(freq);
  }
}

///
///This function resets all the game variables to their default values
///
void Reset(){
  flash(500);
  curLen = 0;
  inputCount = 0;
  lastInput = 0;
  expRd = 0;
  btnDwn = false;
  wait = false;
  resetFlag = false;
}

///
/// User lost
///
void Lose(){
  flash(50);  
}

///
/// The arduino shows the user what must be memorized
/// Also called after losing to show you what you last sequence was
///
void playSequence(){
  //Loop through the stored sequence and light the appropriate LEDs in turn
  for(int i = 0; i < curLen; i++){
      Serial.print("Seq: ");
      Serial.print(i);
      Serial.print("Pin: ");
      Serial.println(sequence[i]);
      digitalWrite(sequence[i], HIGH);
      delay(500);
      digitalWrite(sequence[i], LOW);
      delay(250);
    } 
}

///
/// The events that occur upon a loss
///
void DoLoseProcess(){
  Lose();             // Flash all the LEDS quickly (see Lose function)
  delay(1000);
  playSequence();     // Shows the user the last sequence - So you can count remember your best score - Mine's 22 by the way :)
  delay(1000);
  Reset();            // Reset everything for a new game
}

///
/// Where the magic happens
///
void loop() {  
  if(!wait){      
                            //****************//
                            // Arduino's turn //
                            //****************//
    setPinDirection(OUTPUT);                      // We're using the LEDs
    
    randomSeed(analogRead(A0));                   // https://www.arduino.cc/en/Reference/RandomSeed
    sequence[curLen] = pins[random(0,noPins)];    // Put a new random value in the next position in the sequence -  https://www.arduino.cc/en/Reference/random
    curLen++;                                     // Set the new Current length of the sequence
    
    playSequence();                               // Show the sequence to the player
    beep(50);                                     // Make a beep for the player to be aware
    
    wait = true;                                  // Set Wait to true as it's now going to be the turn of the player
    inputTime = millis();                         // Store the time to measure the player's response time
  }else{ 
                            //***************//
                            // Player's turn //
                            //***************//
    setPinDirection(INPUT);                       // We're using the buttons

    if(millis() - inputTime > PLAYER_WAIT_TIME){  // If the player takes more than the allowed time,
      DoLoseProcess();                            // All is lost :(
      return;
    }      
        
    if(!btnDwn){                                  // 
      expRd = sequence[inputCount];               // Find the value we expect from the player
      Serial.print("Expected: ");                 // Serial Monitor Output - Should be removed if you removed the Serial.begin above
      Serial.println(expRd);                      // Serial Monitor Output - Should be removed if you removed the Serial.begin above
      
      for(int i = 0; i < noPins; i++){           // Loop through the all the pins
        if(pins[i]==expRd)                        
          continue;                               // Ignore the correct pin
        if(digitalRead(pins[i]) == HIGH){         // Is the buttong pressed
          lastInput = pins[i];
          resetFlag = true;                       // Set the resetFlag - this means you lost
          btnDwn = true;                          // This will prevent the program from doing the same thing over and over again
          Serial.print("Read: ");                 // Serial Monitor Output - Should be removed if you removed the Serial.begin above
          Serial.println(lastInput);              // Serial Monitor Output - Should be removed if you removed the Serial.begin above
        }
      }      
    }

    if(digitalRead(expRd) == 1 && !btnDwn)        // The player pressed the right button
    {
      inputTime = millis();                       // 
      lastInput = expRd;
      inputCount++;                               // The user pressed a (correct) button again
      btnDwn = true;                              // This will prevent the program from doing the same thing over and over again
      Serial.print("Read: ");                     // Serial Monitor Output - Should be removed if you removed the Serial.begin above
      Serial.println(lastInput);                  // Serial Monitor Output - Should be removed if you removed the Serial.begin above
    }else{
      if(btnDwn && digitalRead(lastInput) == LOW){  // Check if the player released the button
        btnDwn = false;
        delay(20);
        if(resetFlag){                              // If this was set to true up above, you lost
          DoLoseProcess();                          // So we do the losing sequence of events
        }
        else{
          if(inputCount == curLen){                 // Has the player finished repeating the sequence
            wait = false;                           // If so, this will make the next turn the program's turn
            inputCount = 0;                         // Reset the number of times that the player has pressed a button
            delay(1500);
          }
        }
      }
    }    
  }
}