#define BGG 3
#define BG 18
#define BD 19
#define BDD 2
#define nbLED 9

byte ledPins[]={4,5,6,7,8,9,10,11,12};
int tempo=200;
int indice=0;
int sens=1;

void setup()
{
  pinMode(BGG, INPUT_PULLUP);
  pinMode(BG, INPUT_PULLUP);
  pinMode(BD, INPUT_PULLUP);
  pinMode(BDD, INPUT_PULLUP);
  for (int i;i<nbLED;i++)
  {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW);
  }
  attachInterrupt(digitalPinToInterrupt(BGG), pluslent, FALLING);
  attachInterrupt(digitalPinToInterrupt(BDD), plusrapid, FALLING);
  attachInterrupt(digitalPinToInterrupt(BD), allerdroite, FALLING);
  attachInterrupt(digitalPinToInterrupt(BG), allergauche, FALLING);
}

void loop()
{
  digitalWrite(ledPins[indice], HIGH);
  delay(tempo);
  digitalWrite(ledPins[indice], LOW);
  indice=indice+sens;
  if (indice>=nbLED) indice=0;
  if (indice <0) indice =nbLED-1;
}

void allerdroite()
{
  sens=1;
}

void allergauche()
{
  sens=-1;
}

void pluslent()
{
  tempo=tempo+50;
  if (tempo > 5000) tempo=5000;
  // tempo=min(tempo,5000);
}

void plusrapid()
{
  tempo=tempo-50;
  if (tempo < 50) tempo=50;
  // tempo=max(tempo,50);
}