arduino_sketch_01.cpp

// Motor A connections
int enA = 9;
int in1 = 8;
int in2 = 7;

void setup() {
  // Set all the motor control pins to outputs
  pinMode(enA, OUTPUT);
  pinMode(in1, OUTPUT);

  
  // Turn off motors - Initial state
  digitalWrite(in1, LOW);
  digitalWrite(in2, LOW);

}

void loop() {
  directionControl();
  delay(200);
}

// This function lets you control spinning direction of motors
void directionControl() {
  // Set motors to maximum speed
  // For PWM maximum possible values are 0 to 255
  analogWrite(enA, 255);

  // Turn on motor A & B
  digitalWrite(in1, LOW);
  digitalWrite(in2, HIGH);
  delay(1000);
  
  // Now change motor directions
  digitalWrite(in1, HIGH);
  digitalWrite(in2, LOW);
  delay(1000);
  

}