Voiture commandée avec Arduino et Processing

int ComuD1 = 1; 
int ComuD2 = 2; 
int ComuG1 = 3; 
int ComuG2 = 4; 

int key = 0; 

void setup() 
{ 
  pinMode(ComuD1, OUTPUT); 
  pinMode(ComuD2, OUTPUT); 
  pinMode(ComuG1, OUTPUT); 
  pinMode(ComuG2, OUTPUT); 

  Serial.begin(9600); 
} 

void loop() 
{ 
  if (Serial.available()) 
  { 
    key = Serial.read(); 
    switch (key) 
    { 
    case 113: 
      digitalWrite(ComuD1, LOW); 
      digitalWrite(ComuG1, HIGH); 
      digitalWrite(ComuD2, LOW); 
      digitalWrite(ComuG2, LOW); 
      break; 
       
    case 100: 
      digitalWrite(ComuG1, LOW); 
      digitalWrite(ComuD1, HIGH); 
      digitalWrite(ComuD2, LOW); 
      digitalWrite(ComuG2, LOW); 
      break; 
       
    case 97: 
      digitalWrite(ComuD1, LOW); 
      digitalWrite(ComuG1, HIGH); 
      digitalWrite(ComuD2, HIGH); 
      digitalWrite(ComuG2, LOW); 
      break; 
       
    case 101: 
      digitalWrite(ComuD1, HIGH); 
      digitalWrite(ComuG1, LOW); 
      digitalWrite(ComuD2, LOW); 
      digitalWrite(ComuG2, HIGH); 
      break; 
       
    case 115: 
      digitalWrite(ComuD1, LOW); 
      digitalWrite(ComuG1, LOW); 
      digitalWrite(ComuD2, LOW); 
      digitalWrite(ComuG2, LOW); 
      break; 
       
    case 122: 
      digitalWrite(ComuD1, HIGH); 
      digitalWrite(ComuG1, HIGH); 
      digitalWrite(ComuD2, LOW); 
      digitalWrite(ComuG2, LOW); 
      break; 
       
    default: 
      Serial.print("commande ");   
      Serial.print(key);   
      Serial.println(" non reconnue."); 
      break; 
    } 
  } 
}

import processing.serial.*; 

int SendValue=0; 

Serial MySerialPort; 

void setup(){ 

  size(250,500); 
  println(Serial.list()); 
   
  MySerialPort = new Serial(this, Serial.list()[1], 9600); 
  delay (100);    

  background (255,255,255); 
  stroke(255,0,0); 
   
  MySerialPort.write(0); 
  delay (100); 
   
  PFont font; 
  textFont(loadFont("comicbd.ttf")); 
   
  text("appuyer sur z pour avancer", 15, 30); 
  text("appuyer sur s pour arrêter", 15, 60); 
  text("appuyer sur q pour tourner brusquement à gauche", 15, 90); 
  text("appuyer sur d pour tourner brusquement à droite", 15, 120); 
  text("appuyer sur a pour tourner lentement à gauche", 15, 150); 
  text("appuyer sur e pour tourner lentement à droite", 15, 180); 
   
} 

void  draw() { 

  if (keyPressed)  { 
    if (key == 'z' || key == 'Z')  { 
      SendValue = 122; 
    } 
    else if (key == 's' || key == 'S')  { 
      SendValue = 115; 
    } 
    else if (key == 'q' || key == 'Q')  { 
      SendValue = 113; 
    } 
    else if (key == 'd' || key == 'D')  { 
      SendValue = 100; 
    } 
    else if (key == 'a' || key == 'A')  { 
      SendValue = 97; 
    } 
    else if (key == 'e' || key == 'E')  { 
      SendValue = 115; 
    } 
  } 
   
  MySerialPort.write(SendValue); 
}