//https://forum.arduino.cc/t/slot-car-lap-counter/1376016
/*
  SN74HC595/6  PIN Equivalente
  14 DS	   14 SER     SERIAL_IN
  13 OE	   13 OE      GND
  12 STCP	 12 RCLK    LATCH
  11 SHCP	 11 SRCLK   CLOCK
  10 MR	   10 SRCLR   +V
  9 Q7S    9 QH      SERIAL_OUT
  15 Q0  A
   1 Q1  F
   2 Q2  G
   3 Q3  E
   4 Q4  D
   5 Q5  C
   6 Q6  B
   7 Q7  DP

  #define SER 7    //data
  #define RCLK 5  // LATCH
  #define SRCLK 6  //            CLOCK
*/
//  ********************************************************************
//  Select count display mode:
//  4 counter   2 display each  4   Pin 9
//  2 counter   4 display  each 2   Pin 10
//  1 counter   8 display       1   Pin 11
//  ********************************************************************
int SRCLK = 6;//SHcp pin of 74HC595
int RCLK = 5;//STcp pin of 74HC595
int SER = 7;//ds pin of 74HC595
int digit1, digit2, digit3, digit4, digit5, digit6, digit7, digit8;
byte segmentsBits[] =    {B01111011, //0
                          B01100000, //1
                          B01011101, //2
                          B01110101, //3
                          B01100110, //4
                          B00110111, //5
                          B00111111, //6
                          B01100001, //7
                          B01111111, //8
                          B01110111 //9
                         };
byte score1 = 0;
byte score2 = 0;
byte score3 = 0;
byte score4 = 0;
#define sns1 2
#define sns2 3
#define sns3 4
#define sns4 8
#define mode4 9
#define mode2 10
#define mode1 11
//------------------------------------------------------------------
void setup() {
  pinMode(SRCLK, OUTPUT);
  pinMode(RCLK, OUTPUT);
  pinMode(SER, OUTPUT);
  digitalWrite(SRCLK, LOW);
  digitalWrite(RCLK, LOW);
  digitalWrite(SER, LOW);
  pinMode(sns1, INPUT_PULLUP);
  pinMode(sns2, INPUT_PULLUP);
  pinMode(sns3, INPUT_PULLUP);
  pinMode(sns4, INPUT_PULLUP);
  pinMode(mode4, INPUT_PULLUP);
  pinMode(mode2, INPUT_PULLUP);
  pinMode(mode1, INPUT_PULLUP);
}
//------------------------------------------------------------------
void loop() {
  // 4 x 2
if (digitalRead(mode4) == LOW) {
  if (digitalRead(sns1) == LOW) {
    delay(30);
    if (digitalRead(sns1) == LOW) {
      while (digitalRead(sns1) == LOW) {}
      score1++;
      if (score1  > 99 )score1 = 0;
    }
  }
  if (digitalRead(sns2) == LOW) {
    delay(30);
    if (digitalRead(sns2) == LOW) {
      while (digitalRead(sns2) == LOW) {}
      score2++;
      if (score2  > 99 )score2 = 0;
    }
  }
  if (digitalRead(sns3) == LOW) {
    delay(30);
    if (digitalRead(sns3) == LOW) {
      while (digitalRead(sns3) == LOW) {}
      score3++;
      if (score3  > 99 )score3 = 0;
    }
  }
  if (digitalRead(sns4) == LOW) {
    delay(30);
    if (digitalRead(sns4) == LOW) {
      while (digitalRead(sns4) == LOW) {}
      score4++;
      if (score4  > 99 )score4 = 0;
    }
  }
}
  // 2 x 4
if (digitalRead(mode2) == LOW) {
  if (digitalRead(sns1) == LOW) {
    delay(30);
    if (digitalRead(sns1) == LOW) {
      while (digitalRead(sns1) == LOW) {}
      score2++;
      if (score2  > 99 ) {
        score2 = 0;
        score1++;
        if (score1  > 99 )score1 = 0;
      }
    }
  }
  if (digitalRead(sns2) == LOW) {
    delay(30);
    if (digitalRead(sns2) == LOW) {
      while (digitalRead(sns2) == LOW) {}
      score4++;
      if (score4  > 99 ) {
        score4 = 0;
        score3++;
        if (score3  > 99 )score3 = 0;
      }
    }
  }
}
  // 1 x 8
if (digitalRead(mode1) == LOW) {
  if (digitalRead(sns1) == LOW) {
    delay(30);
    if (digitalRead(sns1) == LOW) {
      while (digitalRead(sns1) == LOW) {}
      score4++;
      if (score4  > 99 ) {
        score4 = 0;
        score3++;
        if (score3  > 99 ) {
          score3 = 0;
          score2++;
        }
        if (score2  > 99 ) {
          score2 = 0;
          score1++;
        }
        if (score1  > 99 ) {
          score1 = 0;
        }
      }
    }
  }
}
  digit1 = score1 % 10 ; // gets dec
  showDig(digit1, 0xFD);
  digit2 = (score1 / 10) % 10 ; //gets unit
  showDig(digit2, 0xFE);
  digit3 = score2 % 10 ; //gets dec
  showDig(digit3, 0xFB);
  digit4 = (score2 / 10) % 10 ; //gets unit
  showDig(digit4, 0xF7);
  digit5 = score3 % 10 ; //gets dec
  showDig(digit5, 0xEF);
  digit6 = (score3 / 10) % 10 ; //gets unit
  showDig(digit6, 0xDF);
  digit7 = score4 % 10 ; //gets dec
  showDig(digit7, 0xBF);
  digit8 = (score4 / 10) % 10 ; //gets unit
  showDig(digit8, 0x7F);
}
//---------------------------------------------------------------------
void showDig(int digit, byte digitBits) {
  digitalWrite(RCLK, LOW);
  shiftOut(SER, SRCLK, MSBFIRST, digitBits);
  shiftOut(SER, SRCLK, MSBFIRST, segmentsBits[ digit]);
  digitalWrite(RCLK, HIGH);
  delay(1);
}