Bluetooth control car

/*
Code Name: Arduino Bluetooth Car with Front and Back Light Control 
Code URI: https://circuitbest.com/category/arduino-projects/
Before uploading the code you have to install the "Adafruit Motor Shield" library
Open Arduino IDE >> Go to sketch >> Include Libray >> Manage Librays...  >> Search "Adafruit Motor Shield" >> Install the Library
AFMotor Library: https://learn.adafruit.com/adafruit-motor-shield/library-install
Author: Make DIY
Author URI: https://circuitbest.com/author/admin/
Description: This program is used to control a robot using an app that communicates with Arduino through an HC-05 Bluetooth Module.
App URI: https://bit.ly/3mn6LuZ
Version: 1.0
License: Remixing or Changing this Thing is allowed. Commercial use is not allowed.
*/
  
#include <AFMotor.h>
  
//initial motors pin
AF_DCMotor motor1(1, MOTOR12_1KHZ);
AF_DCMotor motor2(2, MOTOR12_1KHZ);
AF_DCMotor motor3(3, MOTOR34_1KHZ);
AF_DCMotor motor4(4, MOTOR34_1KHZ);
  
int val;
int Speeed = 255;
  
void setup()
{
  Serial.begin(9600);  //Set the baud rate to your Bluetooth module.
}
void loop(){
  if(Serial.available() > 0){
    val = Serial.read();
      
    Stop(); //initialize with motors stoped
      
          if (val == 'F'){
          forward();
          }
  
          if (val == 'B'){
          back();
          }
  
          if (val == 'L'){
          left();
          }
  
          if (val == 'R'){
          right();
          }
          if (val == 'I'){
          topright();
          }
  
          if (val == 'J'){
          topleft();
          }
  
          if (val == 'K'){
          bottomright();
          }
  
          if (val == 'M'){
          bottomleft();
          }
          if (val == 'T'){
          Stop();
          }
  }
}
           
  
            
  
  
  
void forward()
{
  motor1.setSpeed(Speeed); //Define maximum velocity
  motor1.run(FORWARD); //rotate the motor clockwise
  motor2.setSpeed(Speeed); //Define maximum velocity
  motor2.run(FORWARD); //rotate the motor clockwise
  motor3.setSpeed(Speeed);//Define maximum velocity
  motor3.run(FORWARD); //rotate the motor clockwise
  motor4.setSpeed(Speeed);//Define maximum velocity
  motor4.run(FORWARD); //rotate the motor clockwise
}
  
void back()
{
  motor1.setSpeed(Speeed); //Define maximum velocity
  motor1.run(BACKWARD); //rotate the motor anti-clockwise
  motor2.setSpeed(Speeed); //Define maximum velocity
  motor2.run(BACKWARD); //rotate the motor anti-clockwise
  motor3.setSpeed(Speeed); //Define maximum velocity
  motor3.run(BACKWARD); //rotate the motor anti-clockwise
  motor4.setSpeed(Speeed); //Define maximum velocity
  motor4.run(BACKWARD); //rotate the motor anti-clockwise
}
  
void left()
{
  motor1.setSpeed(Speeed); //Define maximum velocity
  motor1.run(BACKWARD); //rotate the motor anti-clockwise
  motor2.setSpeed(Speeed); //Define maximum velocity
  motor2.run(BACKWARD); //rotate the motor anti-clockwise
  motor3.setSpeed(Speeed); //Define maximum velocity
  motor3.run(FORWARD);  //rotate the motor clockwise
  motor4.setSpeed(Speeed); //Define maximum velocity
  motor4.run(FORWARD);  //rotate the motor clockwise
}
  
void right()
{
  motor1.setSpeed(Speeed); //Define maximum velocity
  motor1.run(FORWARD); //rotate the motor clockwise
  motor2.setSpeed(Speeed); //Define maximum velocity
  motor2.run(FORWARD); //rotate the motor clockwise
  motor3.setSpeed(Speeed); //Define maximum velocity
  motor3.run(BACKWARD); //rotate the motor anti-clockwise
  motor4.setSpeed(Speeed); //Define maximum velocity
  motor4.run(BACKWARD); //rotate the motor anti-clockwise
}
  
void topleft(){
  motor1.setSpeed(Speeed); //Define maximum velocity
  motor1.run(FORWARD); //rotate the motor clockwise
  motor2.setSpeed(Speeed); //Define maximum velocity
  motor2.run(FORWARD); //rotate the motor clockwise
  motor3.setSpeed(Speeed/3.1);//Define maximum velocity
  motor3.run(FORWARD); //rotate the motor clockwise
  motor4.setSpeed(Speeed/3.1);//Define maximum velocity
  motor4.run(FORWARD); //rotate the motor clockwise
}
  
void topright()
{
  motor1.setSpeed(Speeed/3.1); //Define maximum velocity
  motor1.run(FORWARD); //rotate the motor clockwise
  motor2.setSpeed(Speeed/3.1); //Define maximum velocity
  motor2.run(FORWARD); //rotate the motor clockwise
  motor3.setSpeed(Speeed);//Define maximum velocity
  motor3.run(FORWARD); //rotate the motor clockwise
  motor4.setSpeed(Speeed);//Define maximum velocity
  motor4.run(FORWARD); //rotate the motor clockwise
}
  
void bottomleft()
{
  motor1.setSpeed(Speeed); //Define maximum velocity
  motor1.run(BACKWARD); //rotate the motor anti-clockwise
  motor2.setSpeed(Speeed); //Define maximum velocity
  motor2.run(BACKWARD); //rotate the motor anti-clockwise
  motor3.setSpeed(Speeed/3.1); //Define maximum velocity
  motor3.run(BACKWARD); //rotate the motor anti-clockwise
  motor4.setSpeed(Speeed/3.1); //Define maximum velocity
  motor4.run(BACKWARD); //rotate the motor anti-clockwise
}
  
void bottomright()
{
  motor1.setSpeed(Speeed/3.1); //Define maximum velocity
  motor1.run(BACKWARD); //rotate the motor anti-clockwise
  motor2.setSpeed(Speeed/3.1); //Define maximum velocity
  motor2.run(BACKWARD); //rotate the motor anti-clockwise
  motor3.setSpeed(Speeed); //Define maximum velocity
  motor3.run(BACKWARD); //rotate the motor anti-clockwise
  motor4.setSpeed(Speeed); //Define maximum velocity
  motor4.run(BACKWARD); //rotate the motor anti-clockwise
}
  
  
void Stop()
{
  motor1.setSpeed(0); //Define minimum velocity
  motor1.run(RELEASE); //stop the motor when release the button
  motor2.setSpeed(0); //Define minimum velocity
  motor2.run(RELEASE); //rotate the motor clockwise
  motor3.setSpeed(0); //Define minimum velocity
  motor3.run(RELEASE); //stop the motor when release the button
  motor4.setSpeed(0); //Define minimum velocity
  motor4.run(RELEASE); //stop the motor when release the button
}