// setting integer variables to keep track of the number of seconds, tens of seconds, minutes, and tens of minutes that have passed
// setting a float variable counts to keep track of the number of oscillations measured from the circuit
int secondsOnes = 0;
int secondsTens = 0;
int minutesOnes = 0;
int minutesTens = 0;
float counts = 0;

// defining the setup function to run once at the start
void setup() {
  // setting the pins 13, 12, 11, 10, 9, 8, and 7 as outputs for the seven-segment display
  pinMode(13, OUTPUT);
  pinMode(12, OUTPUT);
  pinMode(11, OUTPUT);
  pinMode(10, OUTPUT);
  pinMode(9, OUTPUT);
  pinMode(8, OUTPUT);
  pinMode(7, OUTPUT);
  // setting pin 2 as an input to track oscillations from the circuit
  pinMode(2, INPUT);
  // calling the setSegment() function for segments 0, 1, 2, and 3 with value 0 to zero the display at the start
  setSegment(0, 0);
  setSegment(1, 0);
  setSegment(2, 0);
  setSegment(3, 0);
}

// setting up the main loop of the program to run repeatedly
void loop() {
  // setting an if statement to check when a high-voltage signal reaches Pin 2 then increasing counts by 1
  if (digitalRead(2) == HIGH){
    counts ++;
  }
  // setting a second if statement to check when the number of counts has reached the threshold for 1 second.
  // This value may differ based on latency in your circuit
  // The ones digit of the seconds is then increased by 1 and the setTime() function is called to set the time 
  // counts is then set back to zero to count the next second
  if (counts == 45000){
    secondsOnes ++;
    setTime();
    counts = 0;
  }
}

// defining the setTime() function that sets the time using the current values in each of the time variables from above
void setTime() {
  // making an if statement that increases the tens digit in the seconds if the ones digit is equal to 10 then resets the ones digit to 0
  if (secondsOnes >= 10) {
    secondsTens ++;
    secondsOnes = 0;
  }
  // making an if statement that increases the ones digit in the minutes if the tens digit of seconds is equal to 6 then resets the tens digit to 0
  if (secondsTens >= 6) {
    minutesOnes ++;
    secondsTens = 0;
  }
  // making an if statement that increases the tens digit in the minutes if the ones digit is equal to 10 then resets the ones digit to 0
  if (minutesOnes >= 10) {
    minutesTens ++;
    minutesOnes = 0;
  }
  // making an if statement that resets the tens digit of the minutes if the tens digit of seconds is equal to 6 
  if (minutesTens >= 6) {
    minutesTens = 0;
  }
  // running the setSegment() function for each of the display segments (0, 1, 2, 3) with values for the tens of minutes, minutes, tens of seconds, and seconds
  // values respectively 
  setSegment(0, minutesTens);
  setSegment(1, minutesOnes);
  setSegment(2, secondsTens);
  setSegment(3, secondsOnes);
}

// defining the setSegment() function that takes in the segment number, s, and the time value, v, as its arguments and sets the seven segment outputs\
// to display the current time
void setSegment(int s, int v){
  // setting pin 13 to high to enable a change in the values on the seven segment
  digitalWrite(13, HIGH);
  // having multiple if/else if statements to check which display we want to change
  // if s = 0 we change the left-most display (tens of minutes)
  // if s = 1 we change the second from the left display (minutes)
  // if s = 2 we change the second from the right display (tens of seconds)
  // if s = 3 we change the right-most display (seconds)
  if (s == 0){
    digitalWrite(12, HIGH);
    digitalWrite(11, HIGH);
  }
  else if (s == 1){
    digitalWrite(12, LOW);
    digitalWrite(11, HIGH);
  }
  else if (s == 2){
    digitalWrite(12, HIGH);
    digitalWrite(11, LOW);
  }
  else if (s == 3){
    digitalWrite(12, LOW);
    digitalWrite(11, LOW);
  }
  // multiple if/else if statements that check what value we assign to the chosen display then setting the pins 10, 9, 8, and 7 to some combination of highs
  // and lows to display the correct value on the display
  if (v == 0){
    digitalWrite(10, LOW);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
    digitalWrite(7, LOW);
  }
  else if (v == 1){
    digitalWrite(10, HIGH);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
    digitalWrite(7, LOW);
  }
  else if (v == 2){
    digitalWrite(10, LOW);
    digitalWrite(9, HIGH);
    digitalWrite(8, LOW);
    digitalWrite(7, LOW);
  }
  else if (v == 3){
    digitalWrite(10, HIGH);
    digitalWrite(9, HIGH);
    digitalWrite(8, LOW);
    digitalWrite(7, LOW);
  }
  else if (v == 4){
    digitalWrite(10, LOW);
    digitalWrite(9, LOW);
    digitalWrite(8, HIGH);
    digitalWrite(7, LOW);
  }
  else if (v == 5){
    digitalWrite(10, HIGH);
    digitalWrite(9, LOW);
    digitalWrite(8, HIGH);
    digitalWrite(7, LOW);
  }
  else if (v == 6){
    digitalWrite(10, LOW);
    digitalWrite(9, HIGH);
    digitalWrite(8, HIGH);
    digitalWrite(7, LOW);
  }
  else if (v == 7){
    digitalWrite(10, HIGH);
    digitalWrite(9, HIGH);
    digitalWrite(8, HIGH);
    digitalWrite(7, LOW);
  }
  else if (v == 8){
    digitalWrite(10, LOW);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
    digitalWrite(7, HIGH);
  }
  else if (v == 9){
    digitalWrite(10, HIGH);
    digitalWrite(9, LOW);
    digitalWrite(8, LOW);
    digitalWrite(7, HIGH);
  }
  // setting pin 13 back to low to stop changes from being made
  digitalWrite(13, LOW);
}