Hackidemia Activity 2 and 3

#include <Servo.h> 
#include <math.h>
 
Servo myservo;  // create servo object to control a servo 
 
int potVal = 0;    // variable to read the value from the analog pin 
int processedPotVal = 0;
int photoVal;  // variable to read the value from the photoresistor

const int ledPin1 = 3;
const int ledPin2 = 4;
const int ledPin3 = 5;
const int ledPin4 = 6;

const int servoPin = 9;
const int buzzerPin = 10;

const int potAPin = A0;
const int photoAPin = A1;

const int songLength = 20;
const int tempo = 20;
//int notes[] = {  'C',  'b',  'g',  'C',  'b',   'e',  'R',  'C',  'c', 'g', 'a', 'C' };
char notes[21] = "dafcdadcfdacdafcdaag";

//int beats[]  = { 16, 16, 16,  8,  8,  16, 32, 16, 16, 16, 8, 8 }; 
int beats[] = {8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8};


int lightState = 0;

void setup() {
  pinMode(ledPin1, INPUT);
  pinMode(ledPin2, INPUT);
  pinMode(ledPin3, INPUT);
  pinMode(ledPin4, INPUT);

  pinMode(potAPin, INPUT);
  myservo.attach(servoPin);
  Serial.begin(14400);
}

void loop() {
  
  randomSequence();
  potVal = analogRead(potAPin);
  potVal = map(potVal, 0, 1023, 0, 179);
  potVal = (potVal / 5 ) * 5;
  if (potVal != processedPotVal) {
      Serial.print("Potentiometer: ");
      Serial.println(potVal);
      processedPotVal = potVal;
      myservo.write(processedPotVal);
  }
  
  photoVal = analogRead(photoAPin);
  //Serial.print("Photo resistor: ");
  //Serial.println(photoVal);
  
  if (photoVal > 1000) {
    for (int i = 0; i < songLength; i++) { // step through the song arrays
      int duration = beats[i] * tempo;     // length of note/rest in ms
    
      if (notes[i] == ' ') {      // is this a rest? 
        delay(duration);               // then pause for a moment
      } else {
        tone(buzzerPin, frequency(notes[i]), duration);
        delay(duration);               // wait for tone to finish
      }
      delay(tempo/10);                 // brief pause between notes
    }
  } else {
    delay(500);
  }
}

void randomSequence() {
  if (lightState == 0) {
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, HIGH);
    digitalWrite(ledPin3, HIGH);
    digitalWrite(ledPin4, HIGH);

    lightState++;
  } else if (lightState == 1) {
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, LOW);
    digitalWrite(ledPin3, HIGH);
    digitalWrite(ledPin4, LOW);

    lightState += 1;
  } else if (lightState == 2) {
    digitalWrite(ledPin1, HIGH);
    digitalWrite(ledPin2, HIGH);
    digitalWrite(ledPin3, LOW);
    digitalWrite(ledPin4, LOW);
    lightState += 1;
  }  else if (lightState == 3) {
    digitalWrite(ledPin1, LOW);
    digitalWrite(ledPin2, HIGH);
    digitalWrite(ledPin3, LOW);
    digitalWrite(ledPin4, HIGH);

    lightState = 0;  
  }
}

int frequency(char note) 
{
  // This function takes a note character (a-g), and returns the
  // corresponding frequency in Hz for the tone() function.
  int i;
  const int numNotes = 8;  // number of notes we're storing
  
  // For the "char" (character) type, we put single characters
  // in single quotes.
  char names[] = { 'c', 'd', 'e', 'f', 'g', 'a', 'b', 'C'};
  int frequencies[] = {262, 294, 330, 349, 392, 440, 494, 523};
  
  // Now we'll search through the letters in the array, and if
  // we find it, we'll return the frequency for that note.
  for (i = 0; i < numNotes; i++) {  // Step through the notes
    if (names[i] == note) {         // Is this the one?
      return(frequencies[i]);       // Yes! Return the frequency
    }
  }
  return(0);  // We looked through everything and didn't find it,
              // but we still need to return a value, so return 0.
}