Fio Xbee communication

I modified the "lumiere" function according to your recommendations:

void lumiere()
{
  AV = analogRead(photoAV);
  GA = analogRead(photoGA);
  DR = analogRead(photoDR);
  if(AV > GA && AV > DR){ 
    Serial.print('H');
    digitalWrite(led10, LOW);
    digitalWrite(led12, LOW);
    moteur(0, false, 0, false, 500);
  }
  else{
    digitalWrite(led10, HIGH);
    digitalWrite(led12, LOW);
    Serial.print('L');
    while (Serial.available()) {
      // read the oldest byte in the serial buffer:
      incomingByte = Serial.read();
      // if it's a capital H (ASCII 72), turn motors in one direction:
      if (incomingByte == 'H') {
        moteuravance(255, false, 0, true);
      }
      else if (incomingByte == 'L') {
        moteuravance(0, true, 255, false);
      }
    }
  }
}

and it works.... Thanks a lot!