int pulsanteA=10;
int pulsanteB=11;
int pulsanteC=12;
int pulsanteD=13;
int releGroup4=6;
int releGroup3=7;
int releGroup2=8;
int releGroup1=9;

int group=1;
int offset=0;
int groupReleIndex[4]={
  0, 0, 0, 0,};
int releIndex=0;
int rele[30]={
  22,23,24,25,26,27,28,29,30,31,32,33,34,35,36,
  37,38,39,40,41};

bool ONS1=false, ONS2=false, ONS3=false, ONS4=false; 
bool resetActive=false, startReset=false;

void setup() {
Serial.begin(9600);

  pinMode(pulsanteB, INPUT_PULLUP);
  pinMode(pulsanteA, INPUT_PULLUP);
  pinMode(pulsanteC, INPUT_PULLUP);
  pinMode(pulsanteD, INPUT_PULLUP);
  pinMode(releGroup1, OUTPUT);
  pinMode(releGroup2, OUTPUT);
  pinMode(releGroup3, OUTPUT);
  pinMode(releGroup4, OUTPUT);
 
  for(int pin=0; pin<30; pin++){
  pinMode(rele[pin], OUTPUT);
  }
}

void loop() {

  if(!digitalRead(pulsanteA) and !ONS1){
    ONS1=true;
    groupReleIndex[group-1]=releIndex;
    group++;
    releIndex=groupReleIndex[group-1];
    offset+=5;
    if(group>4){
    group=4;
    offset=15;
    }
    delay(200);
  }
  if(digitalRead(pulsanteA)){
    ONS1=false;
  }

    if(!digitalRead(pulsanteB) and !ONS2){
    ONS2=true;
    groupReleIndex[group-1]=releIndex;
    group--;
    releIndex=groupReleIndex[group-1];
    offset-=5;
    if(group<1){
    group=1;
    releIndex=groupReleIndex[group-1];
    offset=0;
    }
    delay(200);
  }
  if(digitalRead(pulsanteB)){
    ONS2=false;
  }

  if(!digitalRead(pulsanteC) and !ONS3){
    ONS3=true;
    if(releIndex>4){
      releIndex=4;
    }
    digitalWrite(rele[releIndex+offset], HIGH);
    releIndex++;
    delay(200);
  }
  if(digitalRead(pulsanteC)){
    ONS3=false;
  }

  if(!digitalRead(pulsanteD) and !ONS4){
    ONS4=true;
    releIndex--;
    if(releIndex<0){
      releIndex=0;
    }
    digitalWrite(rele[releIndex+offset], LOW);
  }
  if(digitalRead(pulsanteD)){
    ONS4=false;
  }
  switch (group) {
    case 1:
      digitalWrite(releGroup1, HIGH);
      digitalWrite(releGroup2, LOW);
      digitalWrite(releGroup3, LOW);
      digitalWrite(releGroup4, LOW);
    break;

    case 2:
      digitalWrite(releGroup1, LOW);
      digitalWrite(releGroup2, HIGH);
      digitalWrite(releGroup3, LOW);
      digitalWrite(releGroup4, LOW);
    break;

    case 3:
      digitalWrite(releGroup1, LOW);
      digitalWrite(releGroup2, LOW);
      digitalWrite(releGroup3, HIGH);
      digitalWrite(releGroup4, LOW);
    break;

    case 4:
      digitalWrite(releGroup1, LOW);
      digitalWrite(releGroup2, LOW);
      digitalWrite(releGroup3, LOW);
      digitalWrite(releGroup4, HIGH);
    break;
    
  }
    }