// by Nissanka MD Weerasinghe SLCOTM
// this has trick to remove visibility of tuning off of some segments
// when display number change.
// This single program can use for both common anode or cathode cases only to 
// change the setting at the begining. 
// Make sure to use transistors at common cathod pin to handle the current
// as micro controller pin itself may be incapable of handling current for 
// multiple segments on.

bool Common_Anode = false; // make this false for common cathod, true for commom anode
bool SegOn = !Common_Anode;

int Common_Pin_No = 13;

void setup() {
  pinMode(Common_Pin_No, OUTPUT);
  digitalWrite(Common_Pin_No,Common_Anode);
 for(int i = 2; i<9;i++)
 {
    pinMode(i, OUTPUT);
    digitalWrite(i, SegOn);
    delay(100);
 }

 delay(300);





}

void loop() {
SSD0();
delay(1000);

SSD1();
delay(1000);

SSD2();
delay(1000);

SSD3();
delay(1000);

SSD4();
delay(1000);

SSD5();
delay(1000);

SSD6();
delay(1000);

SSD7();
delay(1000);

SSD8();
delay(1000);

SSD9();
delay(1000);



/*


*/
}

void clear()
{
    //erase display (turn off All segments) and turn off display by common line
  for(int i = 2; i<9;i++) digitalWrite(i, !SegOn);
  digitalWrite(Common_Pin_No, !Common_Anode); // turn SSD off
}

void SSD_on()
{
  delay(50); // only for wokwi simulation
  digitalWrite(13, Common_Anode);
}


void All()
{
  for(int i = 2; i<9;i++)
 {

  digitalWrite(i, SegOn);
 }

}

void SSD0()   // Display 1
{

  clear();
  All();
  digitalWrite(8,!SegOn);
  SSD_on();

}


void SSD1()   // Display 1
{

  clear();
  digitalWrite(3,SegOn);
  digitalWrite(4,SegOn);
  SSD_on();

}

void SSD2()   // Display 2
{

  clear(); 
  All();
  digitalWrite(4,!SegOn);
  digitalWrite(7,!SegOn);
  SSD_on();

}


void SSD3()
{

  clear(); 
  All();
  digitalWrite(6,!SegOn);
  digitalWrite(7,!SegOn);
  SSD_on();

}

void SSD4()
{

  clear(); 
  All();
  digitalWrite(2,!SegOn);
  digitalWrite(5,!SegOn);
  digitalWrite(6,!SegOn);
  SSD_on();

}

void SSD5()
{

  clear(); 
  All();
  digitalWrite(3,!SegOn);
  digitalWrite(6,!SegOn);
  SSD_on();

}

void SSD6()
{

  clear(); 
  All();
  digitalWrite(3,!SegOn);
  SSD_on();

}

void SSD7()
{

  clear(); 
  digitalWrite(2,SegOn);
  digitalWrite(3,SegOn);
  digitalWrite(4,SegOn);
  SSD_on();

}

void SSD8()
{

  clear(); 
  All();
  SSD_on();

}

void SSD9()
{

  clear(); 
  All();
  digitalWrite(6,!SegOn);
  SSD_on();

}