int latchPin = 5;  // Latch pin of 74HC595 is connected to Digital pin 5
int clockPin = 6;  // Clock pin of 74HC595 is connected to Digital pin 6
int dataPin = 4;
int digitSelect2Pin = 7;
int digitSelect1Pin = 12;
int digitSelect3Pin = 11;
int digitSelect4Pin = 10;
// Data pin of 74HC595 is connected to Digital pin 4
int t = 0;
int s = 0;
int x = 0;
int f = 0;
byte leds1 = 0;
byte leds2 = 0;
byte leds3 = 0;
byte leds4 = 0;
int analogpin = A0;
int speed = 0;                                  // Higher = slower count
                                                // Variable to hold the pattern of which LEDs are currently turned on or off
int num1[10][7] = { { 1, 1, 1, 1, 1, 1, 0 },    // 0
                    { 0, 1, 1, 0, 0, 0, 0 },    // 1
                    { 1, 1, 0, 1, 1, 0, 1 },    // 2
                    { 1, 1, 1, 1, 0, 0, 1 },    // 3
                    { 1, 1, 1, 0, 0, 1, 0 },    // 4
                    { 1, 0, 1, 1, 0, 1, 1 },    // 5
                    { 1, 0, 1, 1, 1, 1, 1 },    // 6
                    { 1, 1, 0, 0, 0, 1 },       // 7
                    { 1, 1, 1, 1, 1, 1, 1 },    // 8
                    { 1, 1, 1, 0, 0, 1, 1 } };  // 9

int num[16][1] = {
  { 63 },   // 0  Add 128 to turn decimal point
  { 48 },   // 1
  { 109 },  // 2
  { 121 },  // 3
  { 114 },  // 4
  { 91 },   // 5
  { 95 },   // 6
  { 49 },   // 7
  { 127 },  // 8
  { 115 },  // 9
  { 119 },  //A
  { 94 },   //b
  { 15 },   //C
  { 124 },  //D
  { 79 },   //E
  { 71 },   //F
};

int test[5][5]{ 1, 2, 3, 4, 5, 67, 8, 9, 10 };

/*
 * setup() - this function runs once when you turn your Arduino on
 * We initialize the serial connection with the computer
 */
void setup() {
  // Set all the pins of 74HC595 as OUTPUT
  pinMode(latchPin, OUTPUT);
  pinMode(dataPin, OUTPUT);
  pinMode(clockPin, OUTPUT);
  pinMode(digitSelect1Pin, OUTPUT);
  pinMode(digitSelect2Pin, OUTPUT);
  pinMode(digitSelect3Pin, OUTPUT);
  pinMode(digitSelect4Pin, OUTPUT);
  Serial.begin(9600);
  digitalWrite(digitSelect1Pin, 0);
  digitalWrite(digitSelect2Pin, 1);
  digitalWrite(digitSelect3Pin, 1);
  digitalWrite(digitSelect4Pin, 1);
}

void loop() {
  d1();
}

void d1() {
  for (x = 0; x < 10; x++) {

    leds4 = num[x][0];

    if (f < 9)
      leds4 = 0;

    if (x == 0)
      leds4 = 0;
    d2();
  }
}

void d2() {
  for (t = 0; t < 10; t++) {

    leds3 = num[t][0];

    if (f < 9)
      leds3 = 0;
    if (t == 0 && x == 0) {
      leds3 = 0;
    }
    d3();
  }
}
void d3() {
  for (s = 0; s < 10; s++) {

    leds2 = num[s][0];
    if (f < 9)
      leds2 = 0;
    if (t == 0 && x == 0 && s == 0) {
      leds2 = 0;
    }
    d4();
  }
}
void d4() {
  for (f = 0; f < 10; f++) {
    leds1 = num[f][0];

    speed = analogRead(A0);
    if (speed == 0)
      speed = 1;
    //Serial.println(speed);
    for (int w = 0; w < speed; w++) {  //Dislplays the same output "speed" times Higher= slower
      digitalWrite(digitSelect1Pin, 0);
      updateShiftRegister1();            // this togles the digit on and off very fast so it looks like
      digitalWrite(digitSelect1Pin, 1);  //it is on all the time.

      digitalWrite(digitSelect2Pin, 0);
      updateShiftRegister2();
      digitalWrite(digitSelect2Pin, 1);

      digitalWrite(digitSelect3Pin, 0);
      updateShiftRegister3();
      digitalWrite(digitSelect3Pin, 1);

      digitalWrite(digitSelect4Pin, 0);
      updateShiftRegister4();
      digitalWrite(digitSelect4Pin, 1);

    }  //w for loop
  }
}

/*
 * updateShiftRegister() - This function sets the latchPin to low, then calls the Arduino function
  'shiftOut' to shift out contents of variable 'ledsx' in the shift register before putting the
   'latchPin' high again.
 */
void updateShiftRegister1() {

  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, LSBFIRST, leds1);
  digitalWrite(latchPin, HIGH);
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, LSBFIRST, 0);
  digitalWrite(latchPin, HIGH);
}

void updateShiftRegister2() {

  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, LSBFIRST, leds2);
  digitalWrite(latchPin, HIGH);
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, LSBFIRST, 0);
  digitalWrite(latchPin, HIGH);
}

void updateShiftRegister3() {

  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, LSBFIRST, leds3);
  digitalWrite(latchPin, HIGH);
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, LSBFIRST, 0);
  digitalWrite(latchPin, HIGH);
}

void updateShiftRegister4() {

  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, LSBFIRST, leds4);
  digitalWrite(latchPin, HIGH);
  digitalWrite(latchPin, LOW);
  shiftOut(dataPin, clockPin, LSBFIRST, 0);
  digitalWrite(latchPin, HIGH);
}