/*
   Forum: https://forum.arduino.cc/t/4-digit-7-segment-display-not-increasing/1215547
   Wokwi: https://wokwi.com/projects/387907551042549761
*/

/*
 * Author: SMRAZA KEEN
 * Date:2016/6/29
 * IDE V1.6.9
 * Email:[email protected]
 * Function:
 */
int ASeg = 9;
int BSeg = 13;
int CSeg = 4;
int DSeg = 6;
int ESeg = 7;
int FSeg = 10;
int GSeg = 3;

int a1 = 8;
int a2 = 11;
int a3 = 12;
int a4 = 2;
// set variable
long n = 1;
int x = 1;

int del = 500; // fine adjustment for clock

void setup()
{
  pinMode(a1, OUTPUT);
  pinMode(a2, OUTPUT);
  pinMode(a3, OUTPUT);
  pinMode(a4, OUTPUT);
  pinMode(ASeg, OUTPUT);
  pinMode(BSeg, OUTPUT);
  pinMode(CSeg, OUTPUT);
  pinMode(DSeg, OUTPUT);
  pinMode(ESeg, OUTPUT);
  pinMode(FSeg, OUTPUT);
  pinMode(GSeg, OUTPUT);
}

unsigned long lastCount = 0;

void loop()
{
   printToSeg();
   if (millis()-lastCount > 100){
      lastCount = millis();
      n++;    
   }
  }

void printToSeg(){
  long divider = 1000;
  for (int digit = 1;digit < 5; digit++){
   clearLEDS();  // Eliminating ghost
   pickDigit(digit);  // Display position digit
   pickNumber((n/divider)%10); // Display number
   delayMicroseconds(del);  // Time adjustment
   divider = divider/10;
  }
}

// Select display position
void pickDigit(int x) 
{
  digitalWrite(a1, LOW);
  digitalWrite(a2, LOW);
  digitalWrite(a3, LOW);
  digitalWrite(a4, LOW);

  switch(x)
  {
  case 1:
    digitalWrite(a1, HIGH);
    break;
  case 2:
    digitalWrite(a2, HIGH);
    break;
  case 3:
    digitalWrite(a3, HIGH);
    break;
  case 4:
    digitalWrite(a4, HIGH);
    break;  
  }
}
// select display number 
void pickNumber(int x) 
 {
   switch(x) {
    
   case 1: one(); break;
   case 2: two(); break;
   case 3: three(); break;
   case 4: four(); break;
   case 5: five(); break;
   case 6: six(); break;
   case 7: seven(); break;
   case 8: eight(); break;
   case 9: nine(); break;
   default: zero(); break;
 }
}

void clearLEDS()  // clear the screen
{
   digitalWrite(ASeg, HIGH);
   digitalWrite(BSeg, HIGH);
   digitalWrite(CSeg, HIGH);
   digitalWrite(DSeg, HIGH);
   digitalWrite(ESeg, HIGH);
   digitalWrite(FSeg, HIGH);
   digitalWrite(GSeg, HIGH);
}

//Display function ‘0-9’
void zero() {
  digitalWrite(ASeg, LOW);
  digitalWrite(BSeg, LOW);
  digitalWrite(CSeg, LOW);
  digitalWrite(DSeg, LOW);
  digitalWrite(ESeg, LOW);
  digitalWrite(FSeg, LOW);
  digitalWrite(GSeg, HIGH);
}

void one() { 
  digitalWrite(ASeg, HIGH);
  digitalWrite(BSeg, LOW);
  digitalWrite(CSeg, LOW);
  digitalWrite(DSeg, HIGH);
  digitalWrite(ESeg, HIGH);
  digitalWrite(FSeg, HIGH);
  digitalWrite(GSeg, HIGH);
}

void two() {
  digitalWrite(ASeg, LOW);
  digitalWrite(BSeg, LOW);
  digitalWrite(CSeg, HIGH);
  digitalWrite(DSeg, LOW);
  digitalWrite(ESeg, LOW);
  digitalWrite(FSeg, HIGH);
  digitalWrite(GSeg, LOW);
}

void three() {
  digitalWrite(ASeg, LOW);
  digitalWrite(BSeg, LOW);
  digitalWrite(CSeg, LOW);
  digitalWrite(DSeg, LOW);
  digitalWrite(ESeg, HIGH);
  digitalWrite(FSeg, HIGH);
  digitalWrite(GSeg, LOW);
}
void four() {
  digitalWrite(ASeg, HIGH);
  digitalWrite(BSeg, LOW);
  digitalWrite(CSeg, LOW);
  digitalWrite(DSeg, HIGH);
  digitalWrite(ESeg, HIGH);
  digitalWrite(FSeg, LOW);
  digitalWrite(GSeg, LOW);
}
void five() {
  digitalWrite(ASeg, LOW);
  digitalWrite(BSeg, HIGH);
  digitalWrite(CSeg, LOW);
  digitalWrite(DSeg, LOW);
  digitalWrite(ESeg, HIGH);
  digitalWrite(FSeg, LOW);
  digitalWrite(GSeg, LOW);
}
void six() {
  digitalWrite(ASeg, LOW);
  digitalWrite(BSeg, HIGH);
  digitalWrite(CSeg, LOW);
  digitalWrite(DSeg, LOW);
  digitalWrite(ESeg, LOW);
  digitalWrite(FSeg, LOW);
  digitalWrite(GSeg, LOW);
}

void seven() {
  digitalWrite(ASeg, LOW);
  digitalWrite(BSeg, LOW);
  digitalWrite(CSeg, LOW);
  digitalWrite(DSeg, HIGH);
  digitalWrite(ESeg, HIGH);
  digitalWrite(FSeg, HIGH);
  digitalWrite(GSeg, HIGH);
}

void eight() {
  digitalWrite(ASeg, LOW);
  digitalWrite(BSeg, LOW);
  digitalWrite(CSeg, LOW);
  digitalWrite(DSeg, LOW);
  digitalWrite(ESeg, LOW);
  digitalWrite(FSeg, LOW);
  digitalWrite(GSeg, LOW);
}

void nine() {
  digitalWrite(ASeg, LOW);
  digitalWrite(BSeg, LOW);
  digitalWrite(CSeg, LOW);
  digitalWrite(DSeg, LOW);
  digitalWrite(ESeg, HIGH);
  digitalWrite(FSeg, LOW);
  digitalWrite(GSeg, LOW);
}