/* Push button and seven segment display

Circuit Connections:
Seven segment common Cathode = > Gnd
PIN_0 => Resistor 220Ω => Segment a
PIN_1 => Resistor 220Ω => Segment b
PIN_2 => Resistor 220Ω => Segment c
PIN_3 => Resistor 220Ω => Segment f
PIN_4 => Resistor 220Ω => Segment g
PIN_5 => Resistor 220Ω => Segment d
PIN_6 => Resistor 220Ω => Segment e
PIN_7 => Pull-up resistor (built in) => push-button (Gnd)
*/

#define A_pin 0  //give the name “A_pin” to PIN_0
#define B_pin 1 //give the name “B_pin” to PIN_1
#define C_pin 2 //give the name “C_pin” to PIN_2
#define D_pin 5 //give the name “D_pin” to PIN_5
#define E_pin 6 //give the name “E_pin” to PIN_6
#define F_pin 3 //give the name “F_pin” to PIN_3
#define G_pin 4 //give the name “G_pin” to PIN_4
#define pb_pin 7          //give the name “pb_pin” to PIN_7

boolean pressAndReleased=false;     //flag for push-button

//The setup() function initializes and sets the initial values
//It will only run once after each powerup or reset
void setup() {
  pinMode(A_pin, OUTPUT);  //Configure the PIN_0 to behave as output
  pinMode(B_pin, OUTPUT);  //Configure the PIN_1 to behave as output
  pinMode(C_pin, OUTPUT);  //Configure the PIN_2 to behave as output
  pinMode(D_pin, OUTPUT);  //Configure the PIN_5 to behave as output
  pinMode(E_pin, OUTPUT);  //Configure the PIN_6 to behave as output
  pinMode(F_pin, OUTPUT);  //Configure the PIN_3 to behave as output
  pinMode(G_pin, OUTPUT);  //Configure the PIN_4 to behave as output
  //Configure PIN_7 to behave as input with activated pull-up resistor
  pinMode(pb_pin, INPUT_PULLUP);
}

//This function loops consecutively
void loop() {
  if (digitalRead(pb_pin)==0){ //push-button pressed
    delay(25);  //debounce
      while(digitalRead(pb_pin)==0){;}
      //push-button released
      delay(25);    //debounce
      //set the flag to true
      pressAndReleased=true;
  }
  //check the flag for push-button press and release
  if (pressAndReleased == true){
      //call the function “sevenSegment” and display the numbers from 0 to 9
      for (int i=0; i<10; i++){
         sevenSegment(i);
         delay(500);     //wait for 0.5 second
      }  
      //set the flag to false
      pressAndReleased =false;
      //deactivate every segment 
      digitalWrite(A_pin, LOW);
      digitalWrite(B_pin, LOW);
      digitalWrite(C_pin, LOW);
      digitalWrite(D_pin, LOW);
      digitalWrite(E_pin, LOW);
      digitalWrite(F_pin, LOW);
      digitalWrite(G_pin, LOW);
  }    
}

//This function activates and deactivates the segments 
//so the numbers appear on the display
void sevenSegment (int selection){
  switch(selection){
  case 0:
  /* display 0
        -
       |  |
       |  |
        -
    */
    digitalWrite(A_pin, HIGH);  //activate segment A
    digitalWrite(B_pin, HIGH);  //activate segment B
    digitalWrite(C_pin, HIGH);  //activate segment C
  digitalWrite(D_pin, HIGH);  //activate segment D
    digitalWrite(E_pin, HIGH);  //activate segment E
    digitalWrite(F_pin, HIGH);  //activate segment F
    digitalWrite(G_pin, LOW);   //deactivate segment G
    break;
    
  case 1:
 /* display 1
      
         |
         |
        
    */
  digitalWrite(A_pin, LOW);   //deactivate segment A
  digitalWrite(B_pin, HIGH);  //activate segment B
  digitalWrite(C_pin, HIGH);  //activate segment C
  digitalWrite(D_pin, LOW);   //deactivate segment D
  digitalWrite(E_pin, LOW);   //deactivate segment E
    digitalWrite(F_pin, LOW);     //deactivate segment F
    digitalWrite(G_pin, LOW);   //deactivate segment G
    break;
    
  case 2:
  /* display 2
        -
         |
        -
       | 
        -
    */
    digitalWrite(A_pin, HIGH);  //activate segment A
    digitalWrite(B_pin, HIGH);  //activate segment B
    digitalWrite(C_pin, LOW);     //deactivate segment C
    digitalWrite(D_pin, HIGH);  //activate segment D
    digitalWrite(E_pin, HIGH);  //activate segment E
    digitalWrite(F_pin, LOW);   //deactivate segment F
    digitalWrite(G_pin, HIGH);  //activate segment G
    break;
    
  case 3:
  /* display 3
        -
         |
        -
         | 
        -
    */
    digitalWrite(A_pin, HIGH);  //activate segment A
    digitalWrite(B_pin, HIGH);  //activate segment B
    digitalWrite(C_pin, HIGH);  //activate segment C
    digitalWrite(D_pin, HIGH);  //activate segment D
    digitalWrite(E_pin, LOW);   //deactivate segment E
    digitalWrite(F_pin, LOW);   //deactivate segment F
    digitalWrite(G_pin, HIGH);  //activate segment G
    break;
    
  case 4:
  /* display 4
      
       | |
        -
         | 
        
    */
    digitalWrite(A_pin, LOW);   //deactivate segment A
    digitalWrite(B_pin, HIGH);  //activate segment B
    digitalWrite(C_pin, HIGH);  //activate segment C
  digitalWrite(D_pin, LOW);   //deactivate segment D
    digitalWrite(E_pin, LOW);   //deactivate segment E
    digitalWrite(F_pin, HIGH);    //activate segment F
    digitalWrite(G_pin, HIGH);  //activate segment G
    break;
    
  case 5:
  /* display 5
        -
       | 
        -
         | 
        -
    */
    digitalWrite(A_pin, HIGH);  //activate segment A
    digitalWrite(B_pin, LOW);     //deactivate segment B
    digitalWrite(C_pin, HIGH);  //activate segment C
    digitalWrite(D_pin, HIGH);  //activate segment D
    digitalWrite(E_pin, LOW);   //deactivate segment E
    digitalWrite(F_pin, HIGH);  //activate segment F
    digitalWrite(G_pin, HIGH);  //activate segment G  
    break;
    
  case 6:
  /* display 6
      
       | 
        -
       |  | 
        -
    */
    digitalWrite(A_pin, LOW);   //deactivate segment A
    digitalWrite(B_pin, LOW);   //deactivate segment B
    digitalWrite(C_pin, HIGH);  //activate segment C
    digitalWrite(D_pin, HIGH);  //activate segment D
    digitalWrite(E_pin, HIGH);  //activate segment E
    digitalWrite(F_pin, HIGH);    //activate segment F
    digitalWrite(G_pin, HIGH);  //activate segment G
    break;
    
  case 7:
  /* display 7
       _
         |
         | 
        
    */
    digitalWrite(A_pin, HIGH);  //activate segment A
    digitalWrite(B_pin, HIGH);  //activate segment B
    digitalWrite(C_pin, HIGH);  //activate segment C
    digitalWrite(D_pin, LOW);   //deactivate segment D
    digitalWrite(E_pin, LOW);   //deactivate segment E
    digitalWrite(F_pin, LOW);   //deactivate segment F
    digitalWrite(G_pin, LOW);   //deactivate segment G
    break;
    
  case 8:
  /* display 8
        -
       |  |
        -
       |  |
        -
    */
    digitalWrite(A_pin, HIGH);  //activate segment A
    digitalWrite(B_pin, HIGH);  //activate segment B
    digitalWrite(C_pin, HIGH);  //activate segment C
    digitalWrite(D_pin, HIGH);  //activate segment D
    digitalWrite(E_pin, HIGH);  //activate segment E
    digitalWrite(F_pin, HIGH);    //activate segment F
    digitalWrite(G_pin, HIGH);  //activate segment G
    break;
    
  case 9:
  /* display 9
        -
       |  |
        -
          |
         
    */
    digitalWrite(A_pin, HIGH);  //activate segment A
    digitalWrite(B_pin, HIGH);  //activate segment B
    digitalWrite(C_pin, HIGH);  //activate segment C
    digitalWrite(D_pin, LOW);   //deactivate segment D
    digitalWrite(E_pin, LOW);     //deactivate segment E
    digitalWrite(F_pin, HIGH);  //activate segment F
    digitalWrite(G_pin, HIGH);  //activate segment G
    break;
  }
}