void setup()
{
  Serial.begin(115200);
  Serial.println("start");
  pinMode(9, INPUT_PULLUP);
  pinMode(8, INPUT_PULLUP);
  pinMode(7, INPUT_PULLUP);
  pinMode(6, INPUT_PULLUP); 
  pinMode(5, OUTPUT);
  pinMode(4, OUTPUT);
  pinMode(3, OUTPUT);
  pinMode(2, OUTPUT);  

}
void loop()
{
  char var;
  char num;
  if (Serial.available()>0)
  {
  var = Serial.read();
  if( var == 'R' )
  {
    while(Serial.available()<1);
    num = Serial.read();
    byte numpin=num-'0';
    
    if ((numpin>=6) && (numpin<=9))
    {
      byte statusIN=digitalRead(numpin);
      Serial.print("l entree ");
      Serial.print(num);            
      Serial.print(" est a l etat "); 
      Serial.println(statusIN);
     } else Serial.println("erreur PIN");
  } 
   else if( var == 'W')
     {while(Serial.available()<1);
      num = Serial.read();
      byte numpin=num-'0';
      while(Serial.available()<1);
      byte status = Serial.read();
      status=status-'0';
      if ((numpin>=2) && (numpin<=5))
      {
      digitalWrite(numpin,status);
      Serial.print("OK pin ");
      Serial.println(num);
      }else Serial.println("erreur PIN");
     } 
  }
}