//a1,a2 = LOW,HIGH --->clockwise
//a1,a2 = HIGH,LOW --->anti-clockwise
//b1,b2 = LOW,HIGH --->anti-clockwise
//b1,b2 = HIGH,LOW --->clockwise
//a1,a2,b1,b2 = LOW,LOW,LOW,LOW --->brake
//int a_enable=2;// uncomment it if your enable pins are connected to the microcontroller
//int b_enable=5;
#define a1 2
#define a2 3
#define b2 4
#define b1 5
void setup ()
{
  for(int i=2;i<6;i++)
    pinMode(i,OUTPUT);
  //digitalWrite(a_enable,HIGH);// uncomment it if your enable pins are connected to the microcontroller
  //digitalWrite(b_enable,HIGH);
}
void motor_left() // Test,for the left wheel
{
  digitalWrite(b1,LOW);       //anti-clockwise
  digitalWrite(b2,HIGH);
  delay(2500);
  
  digitalWrite(b1,LOW);        //brake
  digitalWrite(b2,LOW);
  delay(1000);
  
  digitalWrite(b1,HIGH);       //clockwise
  digitalWrite(b2,LOW);
  delay(2500);
  
  digitalWrite(b1,LOW);        //brake
  digitalWrite(b2,LOW);
  delay(1000);
}

void motor_right() // Test,for the right wheel
{
  digitalWrite(a1,LOW);       //clockwise
  digitalWrite(a2,HIGH);
  delay(2400);
  
  digitalWrite(a1,LOW);       //brake
  digitalWrite(a2,LOW);
  delay(1000);
  
  digitalWrite(a1,HIGH);      //anti-clockwise
  digitalWrite(a2,LOW);
  delay(2400);
  
  digitalWrite(a1,LOW);       //brake
  digitalWrite(a2,LOW);
  delay(1000);
}

void motor_both()// Test,for both the wheel working simultaneously 
{
  //To Turn LEFT
  digitalWrite(b1,HIGH);       //clockwise
  digitalWrite(b2,LOW);

  digitalWrite(a1,LOW);       //clockwise
  digitalWrite(a2,HIGH);
  delay(2500);
  
  //To BRAKE
  digitalWrite(b1,LOW);       //left brake
  digitalWrite(b2,LOW);

  digitalWrite(a1,LOW);       //right brake
  digitalWrite(a2,LOW);
  delay(1000);
  
 //To Turn RIGHT
  digitalWrite(b1,LOW);       //anti-clockwise
  digitalWrite(b2,HIGH);

  digitalWrite(a1,HIGH);       //anti-clockwise
  digitalWrite(a2,LOW);
  delay(2500);
  
  //To BRAKE AGAIN
  digitalWrite(b1,LOW);       //left brake
  digitalWrite(b2,LOW);

  digitalWrite(a1,LOW);       //right brake
  digitalWrite(a2,LOW);
  delay(1000);
}
void loop()
{
  motor_left();             //Quite sensible to understand..........
  motor_right();
  motor_both();
}