#define numsLeds 9
void gauche();
void droite();
void fast();
void slow();
volatile int sens=1;

volatile int tempo=1;
#define Deltatempo 100
#define Mintempo 100
#define Maxtempo 3000 

int NumPinLed[numsLeds]={4,5,6,7,8,9,10,11,12};
const byte Btn_bgg=2;
const byte Btn_bdd=3;
const byte Btn_bg=18;
const byte Btn_bd=19;

void setup() {
  Serial.begin(115200);
  for(int i=0;i<numsLeds;i++) 
  {
    pinMode(NumPinLed[i], OUTPUT);
    digitalWrite(NumPinLed[i], LOW); 
  }
  pinMode(Btn_bgg, INPUT_PULLUP);
  pinMode(Btn_bdd, INPUT_PULLUP);
  
  attachInterrupt(digitalPinToInterrupt(Btn_bgg),fast , RISING);
  attachInterrupt(digitalPinToInterrupt(Btn_bdd),slow , RISING);
  attachInterrupt(digitalPinToInterrupt(Btn_bg),gauche , FALLING);
  attachInterrupt(digitalPinToInterrupt(Btn_bd),droite , FALLING);
}

int indice=0;
void loop() {
    digitalWrite(NumPinLed[indice], HIGH);   
    delay(tempo);                      
    digitalWrite(NumPinLed[indice], LOW); 
  indice=indice+sens;
  if (indice>=numsLeds) indice=0;  
  if (indice<0) indice=(numsLeds-1);
Serial.println(indice);
//Serial.println(sens);
  /// autre chose à faire   
}

void gauche()
 {
  sens=1;
  }
void droite()
 {
  sens=-1;
  }
void fast()
 {
  tempo=tempo-Deltatempo;
  if (tempo < Mintempo) tempo=Mintempo;
  }
void slow()
 {
  tempo=tempo+Deltatempo;
  if (tempo > Maxtempo) tempo=Maxtempo;
  }