Counter SG

//define bit-patterns for 7 segment display
const int  valuesTable[10] = {
                      B11111001, //1
                      B10100100, //2
                      B10110000, //3
                      B10011001, //4
                      B10010010, //5
                      B10000011, //6
                      B11111000, //7
                      B10000000, //8
                      B10011000, //9
                      B11000000  //0
                    };

const int dataPin = 8;   //74HC595  pin 8 DS
const int latchPin = 9;  //74HC595  pin 9 STCP
const int clockPin = 10; //74HC595  pin 10 SHCP


const int display1 = 7; // displays numbered from left to right
const int display2 = 6;
const int display3 = 5;
const int display4 = 4;

int buttonPin = 3;     // the number of the pushbutton pin

int countedNumber = 0;
int currentButtonState = 0;        // current state of the button
int previousButtonState = 0;       // previous button state

void setup() {
  Serial.begin(9600);

  // declare button pin as input
  // latch, clock, data (part of 74HC595, connected to counter) are output
  // each display is an output

  pinMode(buttonPin, INPUT_PULLUP);

  pinMode(latchPin,OUTPUT);
  pinMode(clockPin,OUTPUT);
  pinMode(dataPin,OUTPUT);

  pinMode(display1, OUTPUT);
  pinMode(display2, OUTPUT);
  pinMode(display3, OUTPUT);
  pinMode(display4, OUTPUT);
}


void allDisplaysOff() {
  // turn all cathode drivers off so that no leading zeros show
  digitalWrite(display1, LOW);
  digitalWrite(display2, LOW);
  digitalWrite(display3, LOW);
  digitalWrite(display4, LOW);
}


// function controls the numbers on display
void displayDigit(int whichDisplay, byte valueToDisplay) {

  digitalWrite(latchPin, LOW); // turn off shift register pins while shifting bits

  allDisplaysOff(); // turn off all cathode drivers

  shiftOut(dataPin,clockPin, LSBFIRST, valueToDisplay); //shift the bits out

  digitalWrite(latchPin, HIGH); // set latch high to set segments

  digitalWrite(whichDisplay, HIGH); // drive on cathode low to durn on display

  delay(100);

}


void segmentDisplay(int number){
  int d1, d2, d3, d4; // temp values for thousands, hundreds, tens, ones


  d1 = (int) (number / 1000); // get thousands
  number = number - (d1 * 1000);  // subtract thousands from number

  d2 = (int) (number / 100); // get hundreds
  number = number - (d2 * 100); // subtract hundreds from number

  d3 = (int) (number / 10); // get tens

  d4 = number - (d3 * 10); // subtract tens from number to obtain d4

  displayDigit(display1, byte(valuesTable[d1])); // display thousands
  displayDigit(display2, byte(valuesTable[d2])); // display hundreds
  displayDigit(display3, byte(valuesTable[d3])); // display tens
  displayDigit(display4, byte(valuesTable[d4])); // display ones


}

// function keeps track of number of button presses, saves in variable called countedNumber
void buttonCount() {

  currentButtonState = digitalRead(buttonPin);      //read state of current pushbutton value, being either low or high

  //off is 1, on is 0 for PULLUP

  if(currentButtonState != previousButtonState){  // if previous button state and current button state are not equal
    if(currentButtonState == 0) {                 // and if current button state is ON
      countedNumber++;                            // increase counted number by 1

      if (countedNumber > 9999) {                 // if counted number exceeds 9999, reset number to 0
        countedNumber = 0;
      }

      if (countedNumber < 0) {                    // if counted number is less than 0, make it equal 0
        countedNumber = 0;

      segmentDisplay(countedNumber);

      }
    }
  }
previousButtonState = currentButtonState; // save current state as last state for next time through the loop

delay(200);

}


void loop() {

buttonCount();
Serial.print("Current Button State: ");
Serial.print(currentButtonState);
Serial.print('\t');
Serial.print("Counted Number: ");
Serial.print(countedNumber);
Serial.println('\t');



}