Movimiento del brazo

gistfile1.ino

char val;         
int ledpingreen = 13;
int potPin = 1;
int E1 = 10;
int M1 = 12;
int E2 = 11;
int M2 = 13;
int potLectura = 0;

void setup()
{
  pinMode(ledpingreen, OUTPUT);  
  pinMode(M1, OUTPUT);
  pinMode(M2, OUTPUT);
  pinMode(E1, OUTPUT);
  pinMode(E2, OUTPUT);
  Serial.begin(115200);       
 
}
 
void loop() {
    potLectura = analogRead(potPin);
    Serial.println(potLectura);
    val = Serial.read();        
    Serial.println(val);

  
 if(val == 'D'){               
      Serial.println("entre der");
   if(potLectura >= 600){
    digitalWrite(ledpingreen, HIGH);  
    digitalWrite(M1,HIGH);
    digitalWrite(M2,HIGH); 
    digitalWrite(E1, HIGH);
    digitalWrite(E2, HIGH);
    Serial.println("Derecha");
    delay(2000);
     digitalWrite(M1,LOW); 
      digitalWrite(M2,LOW); 
     digitalWrite(E1, LOW);
     digitalWrite(E2, LOW);
     Serial.println("Apagado");
  }
 }
  
  if(val == 'I'){ 
    Serial.println("entre izq");
    if(potLectura <= 1000){
      
   digitalWrite(ledpingreen, HIGH);   

   digitalWrite(M1,LOW);
  digitalWrite(M2,LOW); 
   digitalWrite(E1, HIGH);
   digitalWrite(E2, HIGH);
   Serial.println("Izquierda");
   delay(2000);
    digitalWrite(M1,LOW); 
      digitalWrite(M2,LOW); 
     digitalWrite(E1, LOW);
     digitalWrite(E2, LOW);
     Serial.println("Apagado");
    }
  }  
  delay(500);
}