4WD Car Completo

/*
   Marco Cerani
   4WD
   maggio 2018 V3.2 - codice open source
*/
#include <SoftwareSerial.h>
#define bluetooth Serial
SoftwareSerial mySerial(0, 1);
  const int motorA1  = 4;
  const int motorA2  = 5;
  const int motorB1  = 10;
  const int motorB2  = 11;
  const int led  = 12;
  const int clacson = 6 ;
  int i=0;
  int j=0;
  int state;
  int vSpeed=200;

void setup() {
    pinMode(motorA1, OUTPUT);
    pinMode(motorA2, OUTPUT);
    pinMode(motorB1, OUTPUT);
    pinMode(motorB2, OUTPUT);
    pinMode(led, OUTPUT);
    pinMode(clacson,OUTPUT);
    Serial.begin(9600);
}
void loop() {
    if(Serial.available() > 0){
      state = Serial.read();
      Stop();
    }
    if (state == 'A') {
      analogWrite(motorA1, vSpeed);
      analogWrite(motorA2, 0);
      analogWrite(motorB1, vSpeed);
      analogWrite(motorB2, 0);
    }
    else if (state == 'B') {
      analogWrite(motorA1, 0);
      analogWrite(motorA2, vSpeed);
      analogWrite(motorB1, 0);
      analogWrite(motorB2, vSpeed);
    }
    else if (state == 'C') {
      analogWrite(motorA1, 200);
      analogWrite(motorA2, 0);
      analogWrite(motorB1, 0);
      analogWrite(motorB2, 200);
    }
    else if (state == 'D') {
      analogWrite(motorA1, 0);
      analogWrite(motorA2, 200);
      analogWrite(motorB1, 200);
      analogWrite(motorB2, 0);
    }
    else if (state == 'E') {
      if (i==0){
         digitalWrite(led, HIGH);
         i=1;
      }
      else if (i==1){
         digitalWrite(led, LOW);
         i=0;
      }
      state='n';
    }
    else if (state == 'F'){
      if (j==0){
        digitalWrite(clacson, HIGH);
         j=1;
      }
      else if (j==1){
         digitalWrite(clacson, LOW);
         j=0;
      }
      state='n';
    }
    else if (state == 'G'){
        analogWrite(motorA1, 0);
        analogWrite(motorA2, 0);
        analogWrite(motorB1, 0);
        analogWrite(motorB2, 0);
        digitalWrite(clacson, LOW);
    }
}
void Stop() {
  analogWrite(motorA1, 0);
  analogWrite(motorA2, 0);
  analogWrite(motorB1, 0);
  analogWrite(motorB2, 0);
}