int PinOFmotor = 10; 
// PIN 10 of the Arduino is initialized to the variable
// the pin must be a PWM pin
void setup() 
{
 pinMode(PinOFmotor, OUTPUT);
}
void loop() 
{
 digitalWrite(PinOFmotor, HIGH);
 delay(1000); 
 digitalWrite(PinOFmotor, LOW);
 delay(1000);
}

#define MOTOR_1  11 
// PWM pin 11 
#define MOTOR_A     10
// PWM pin 10 
// we can also connect it to the other PWM pins of the Arduino
#define MOTOR_B     8
// digital I/O pin 
 
#define slow 64
#define normal 128
#define fast 255
 
int Speed; // initialization of speed variable

 // created functions
void Forward_Rev(void)
{
  analogWrite(MOTOR_1, Speed);
  digitalWrite(MOTOR_A, HIGH);
  digitalWrite(MOTOR_B, LOW);
}
void Backward_Rev(void)
{
  analogWrite(MOTOR_1, Speed);
  digitalWrite(MOTOR_A, LOW);
  digitalWrite(MOTOR_B, HIGH);
}
 
void Forward_ramp_up(void)
{
  digitalWrite(MOTOR_A, HIGH);
  digitalWrite(MOTOR_B, LOW);
  for (int i=0; i<255; i++) // loop started
    //value set from 0 to 255
  { 
    analogWrite(MOTOR_A, i); 
    delay(15); // delay time in milliseconds
  } 
} 
void Forward_ramp_down(void)
{ 
  digitalWrite(MOTOR_A, HIGH);
  digitalWrite(MOTOR_B, LOW); 
  
  for (int i=255; i>=0; i--) // loop set in reverse direction
   // value set from 255 to 0 (reverse)
  {
    analogWrite(MOTOR_A, i);
    delay(15);
  }
}
 // same statement but within different function
void Backward_ramp_up(void)
{
  digitalWrite(MOTOR_A, LOW);
  digitalWrite(MOTOR_B, HIGH);
  for (int i=0; i<255; i++) 
  { analogWrite(MOTOR_A, i); 
   delay(15); 
   // we can modify the delay time as per the requirements
  } 
} 
void Backward_ramp_down(void)
{ 
  digitalWrite(MOTOR_A, LOW);
  digitalWrite(MOTOR_B, HIGH); 
  
  for (int i=255; i>=0; i--) 
  {
    analogWrite(MOTOR_A, i);
    delay(15);
  }
}
 
void Brake(void)
{
  digitalWrite(MOTOR_A, HIGH);
  digitalWrite(MOTOR_B, HIGH);
}
 
void setup() 
{
  
  Serial.begin(9600); // bps rate of 9600
  Serial.println("DC motor test using L293D");
 
  pinMode(MOTOR_1, OUTPUT);
  pinMode(MOTOR_A, OUTPUT);
  pinMode(MOTOR_B, OUTPUT);
}
 
void loop() 
{
 
  Speed=slow; // Slow Speed
  // we can modify the value as fast, slow, and normal depending on the required speed
  //the motor will revolve according to the specified speed
  // for example, fast will cause it to move at fast speed
  // we can also add more parameters using #define
 
  Forward_Rev(); 
  delay(1000);
  Brake();
  delay(500);
  Backward_Rev(); 
  delay(1000);
  Brake();
  delay(500);
  Forward_ramp_up();
  Forward_ramp_down();
  Backward_ramp_up();
  Backward_ramp_down();
  // the statement inside the functions will run again and again
  // the motor will revolve in forward and backward direction
}