struct FLASH {
  public:
    int Duration ;
    int Delay ;
    int Number;
    int FlowTimer ;
};

int Index;
const FLASH Flash[4] = {{0, 0, 0, 0}, {20, 200, 2, 15000}, {20, 100, 3, 3000}, {20, 50, 5, 1000}};

void setup() {
  Serial.begin(115200);
  Index = 0;
  Serial.print("Dans setup, pour index = "); Serial.print(Index);
  Serial.print("\t"); Serial.print(Flash[Index].Duration);
  Serial.print("\t"); Serial.println(Flash[Index].Delay);
}

void loop() {
  Index++;
  if (Index >= 4) while (true); // on meurt ici
  Serial.print("Dans la loop, pour index = "); Serial.print(Index);
  Serial.print("\t"); Serial.print(Flash[Index].Duration);
  Serial.print("\t"); Serial.println(Flash[Index].Delay);
}