////////////////////////////////
// 4 Digit 7 Segment Display  //
//                            //
// This program allows the    //
// user to set-up a 4 digit 7 //
// segment display.           //
//                            // 
// Codes by:                  //
// eGizmo Mechatronix Central //
// Taft, Manila Philippines   //
// http://www.egizmo.com      //
// April 18, 2013             //
////////////////////////////////

// Constants
const int DataIN =  5;   // Connect data IN to MCU pin 5
const int StrIN =   6;   // Connect str IN to MCU pin 6
const int ClkIN =   7;   // Connect clk IN to MCU pin 7
// This pins are located on the left side of the
// display
// Data in 5th pin 
// Str in 4th pin
// Clk in 3rd pin

// Timer numbers
const byte numbersTimer[10]={
  B10111111,             //0
  B10000110,             //1
  B11011011,             //2
  B11001111,             //3
  B11100110,             //4
  B11101101,             //5
  B11111101,             //6
  B10100111,             //7
  B11111111,             //8
  B11101111};            //9

// NOTE: Use an external supply more than 5V so that
// the display will be more clear.


void setup()
{
  pinMode(DataIN, OUTPUT); // Pin 5 as output
  pinMode(ClkIN, OUTPUT); // Pin 6 as output
  pinMode(StrIN, OUTPUT); // Pin 7 as output
}


void loop()
{

  // This following codes are for testing:

  for(int i = 0; i<=6; i++)
  {
    shiftOut(numbersTimer[0+i]); // 4th digit
    digitalWrite(StrIN, HIGH);
    digitalWrite(StrIN,LOW);

    shiftOut(numbersTimer[1+i]); // 3rd digit
    digitalWrite(StrIN, HIGH);
    digitalWrite(StrIN,LOW);
    
    shiftOut(numbersTimer[2+i]); // 2nd digit
    digitalWrite(StrIN, HIGH);
    digitalWrite(StrIN,LOW);
    
    shiftOut(numbersTimer[3+i]); // 1st digit
    digitalWrite(StrIN, HIGH);
    digitalWrite(StrIN,LOW);

    delay(1000);      // Delay per display
  }
  
  
  
}

void shiftOut(byte DataOUT) // Sets a byte called DataOUT
{
  boolean state;

  // Sets the cycle for data in and clock in
  digitalWrite(DataIN, LOW);
  digitalWrite(ClkIN, LOW);

  for (int i=0; i<=7; i++) 
    // This is set for 8bit binary.
  {
    digitalWrite(ClkIN, LOW);
    if (DataOUT&(1<<i)) 
    {
      state = HIGH;
    }
    else 
    {
      state = LOW;
    }

    digitalWrite(DataIN, state);
    digitalWrite(ClkIN, HIGH);
  }

  digitalWrite(ClkIN,LOW);
}