arduino_car/car.ino

/* Define you pins here */
const int left_wheel_1  = 0;
const int left_wheel_2  = 1;
const int right_wheel_1 = 2;
const int right_wheel_2 = 3;

/* The counter */
int i;

/* Array bellow contains all the wheels */
int Wheels[] = {left_wheel_1, left_wheel_2, right_wheel_1, right_wheel_2};

void setup() {
  /* Setup pins */
  for (i = 0; i < sizeof(Wheels) - 1; i++) {
    pinMode(Wheels[i], OUTPUT);
  }
}

/* Wheel actions */

/* Forward */
void move_forward_wheel_left() {
  digitalWrite(left_wheel_1, HIGH);
  digitalWrite(left_wheel_2, LOW);
}

void move_forward_wheel_right() {
  digitalWrite(right_wheel_1, HIGH);
  digitalWrite(right_wheel_2, LOW);
}

void move_forward() {
  move_forward_wheel_left();
  move_forward_wheel_right();
}

/* Backward */
void move_backward_wheel_left() {
  digitalWrite(left_wheel_1, LOW);
  digitalWrite(left_wheel_2, HIGH);
}

void move_backward_wheel_right() {
  digitalWrite(right_wheel_1, LOW);
  digitalWrite(right_wheel_2, HIGH);
}

void move_backward() {
  move_backward_wheel_left();
  move_backward_wheel_right();
}

/* Stops */
void stop_all() {
  for (i = 0; sizeof(Wheels) - 1; i++) {
    digitalWrite(Wheels[i], LOW);
  }
}

void stop_left() {
  digitalWrite(left_wheel_1, LOW);
  digitalWrite(left_wheel_2, LOW);
}

void stop_right() {
  digitalWrite(right_wheel_1, LOW);
  digitalWrite(right_wheel_2, LOW);
}

/* Turns */
void turn_left(int delayMS) {
  stop_left();
  move_forward_wheel_right();
  delay(delayMS);
}

void turn_right(int delayMS) {
  stop_right();
  move_forward_wheel_left();
  delay(delayMS);
}

/* Main code */
void loop() {
  move_forward();
  delay(1000);
  turn_left(500);
  move_backward();
  delay(1000);
  turn_right(500);
  move_forward();
  turn_left(500);
  turn_left(500);
  turn_left(500);
  move_forward();
  delay(1000);
}