int pin                 = 5;     //      D7 D7 D7
const int MIDDLE        = pin++; //    D6         D8
const int TOP_LEFT      = pin++; //    D6         D8
const int TOP           = pin++; //    D6         D8
const int TOP_RIGHT     = pin++; //       D5 D5 D5
const int BOTTOM_LEFT   = pin++; //    D9         D11
const int BOTTOM        = pin++; //    D9         D11
const int BOTTOM_RIGHT  = pin++; //    D9         D11
const int DOT           = pin++; //     D10 D10 D10    D12


void setup() {
  int pin = MIDDLE;
  pinMode( pin++, OUTPUT );
  pinMode( pin++, OUTPUT );
  pinMode( pin++, OUTPUT );
  pinMode( pin++, OUTPUT );
  pinMode( pin++, OUTPUT );
  pinMode( pin++, OUTPUT );
  pinMode( pin++, OUTPUT );
  pinMode( pin++, OUTPUT );

  // ground pins
  pinMode( A0, OUTPUT ); // 10s digit
  pinMode( A1, OUTPUT ); // 1s digit 

}

void select1s() {
  digitalWrite( A0, HIGH );
  digitalWrite( A1, LOW );
}
void select10s() {
  digitalWrite( A0, LOW );
  digitalWrite( A1, HIGH );
}

void loop() {
  
  int dwell = 100; // max 100ms avoids flicker on wokwi

  blank();
  select10s(); // apply ground to unit 0
  draw2();
  delay( dwell );

  blank();
  select1s(); // apply ground to unit 1
  draw3();
  delay( dwell );

}

// illuminate each segment in turn
void test() {
  long seconds = 1000 * 1; // seconds

  digitalWrite( A0, LOW );
  digitalWrite( A1, LOW );

  pin = MIDDLE;

  digitalWrite( pin, HIGH ); delay( seconds );
  digitalWrite( ++pin, HIGH ); delay( seconds );
  digitalWrite( ++pin, HIGH ); delay( seconds );
  digitalWrite( ++pin, HIGH ); delay( seconds );
  digitalWrite( ++pin, HIGH ); delay( seconds );
  digitalWrite( ++pin, HIGH ); delay( seconds );
  digitalWrite( ++pin, HIGH ); delay( seconds );
  digitalWrite( ++pin, HIGH ); delay( seconds );




}

void blank() {

  pin = MIDDLE;
  digitalWrite( pin, LOW );
  digitalWrite( ++pin, LOW );
  digitalWrite( ++pin, LOW );
  digitalWrite( ++pin, LOW );
  digitalWrite( ++pin, LOW );
  digitalWrite( ++pin, LOW );
  digitalWrite( ++pin, LOW );
  digitalWrite( ++pin, LOW );
}

void draw0() {
  blank();
  digitalWrite( TOP_LEFT, HIGH );
  digitalWrite( TOP, HIGH );
  digitalWrite( TOP_RIGHT, HIGH );
  digitalWrite( BOTTOM_RIGHT, HIGH );
  digitalWrite( BOTTOM, HIGH );
  digitalWrite( BOTTOM_LEFT, HIGH );
}

void draw1() {
  blank();
  digitalWrite( TOP_RIGHT, HIGH );
  digitalWrite( BOTTOM_RIGHT, HIGH );
}

void draw2() {
  blank();
  digitalWrite( TOP, HIGH );
  digitalWrite( TOP_RIGHT, HIGH );
  digitalWrite( MIDDLE, HIGH );
  digitalWrite( BOTTOM_LEFT, HIGH );
  digitalWrite( BOTTOM, HIGH );
}

void draw3() {
  blank();
  digitalWrite( TOP, HIGH );
  digitalWrite( TOP_RIGHT, HIGH );
  digitalWrite( MIDDLE, HIGH );
  digitalWrite( BOTTOM_RIGHT, HIGH );
  digitalWrite( BOTTOM, HIGH );
}

void draw4() {
  blank();
  digitalWrite( TOP_LEFT, HIGH );
  digitalWrite( MIDDLE, HIGH );
  digitalWrite( TOP_RIGHT, HIGH );
  digitalWrite( BOTTOM_RIGHT, HIGH );
}

void draw5() {
  blank();
  digitalWrite( TOP, HIGH );
  digitalWrite( TOP_LEFT, HIGH );
  digitalWrite( MIDDLE, HIGH );
  digitalWrite( BOTTOM_RIGHT, HIGH );
  digitalWrite( BOTTOM, HIGH );
}

void draw6() {
  blank();
  digitalWrite( TOP, HIGH );
  digitalWrite( TOP_LEFT, HIGH );
  digitalWrite( BOTTOM_LEFT, HIGH );
  digitalWrite( BOTTOM, HIGH );
  digitalWrite( BOTTOM_RIGHT, HIGH );
  digitalWrite( MIDDLE, HIGH );
}

void draw7() {
  blank();
  digitalWrite( TOP, HIGH );
  digitalWrite( TOP_RIGHT, HIGH );
  digitalWrite( BOTTOM_RIGHT, HIGH );
}

void draw8() {
  blank();
  digitalWrite( TOP_LEFT, HIGH );
  digitalWrite( TOP, HIGH );
  digitalWrite( TOP_RIGHT, HIGH );
  digitalWrite( MIDDLE, HIGH );
  digitalWrite( BOTTOM_RIGHT, HIGH );
  digitalWrite( BOTTOM, HIGH );
  digitalWrite( BOTTOM_LEFT, HIGH );
}

void draw9() {
  blank();
  digitalWrite( MIDDLE, HIGH );
  digitalWrite( TOP_LEFT, HIGH );
  digitalWrite( TOP, HIGH );
  digitalWrite( TOP_RIGHT, HIGH );
  digitalWrite( BOTTOM_RIGHT, HIGH );
  digitalWrite( BOTTOM, HIGH ); // curly
}