const int LEFT_DIR_PIN = 7;
const int LEFT_SPEED_PIN = 6;
const int RIGHT_DIR_PIN = 4;
const int RIGHT_SPEED_PIN = 5;
const int FORWARD = HIGH;
const int BACKWARD = (FORWARD == HIGH) ? LOW : HIGH;

int speed = 100;

void drive(int leftDir, int leftSpeed, int rightDir, int rightSpeed) {
  digitalWrite(LEFT_DIR_PIN, leftDir);
  digitalWrite(RIGHT_DIR_PIN, rightDir);
  analogWrite(LEFT_SPEED_PIN, leftSpeed);
  analogWrite(RIGHT_SPEED_PIN, rightSpeed);
}

void forward(int ms) {
  drive(FORWARD, speed, FORWARD, speed);
  delay(ms);
}

void backward(int ms) {
  drive(BACKWARD, speed, BACKWARD, speed);
  delay(ms);
}

void stopMotors() {
  analogWrite(LEFT_SPEED_PIN, 0);
  analogWrite(RIGHT_SPEED_PIN, 0);
}

void setup() {
  pinMode(LEFT_DIR_PIN, OUTPUT);
  pinMode(LEFT_SPEED_PIN, OUTPUT);
  pinMode(RIGHT_DIR_PIN, OUTPUT);
  pinMode(RIGHT_SPEED_PIN, OUTPUT);
  stopMotors();
  delay(2000); // время убрать руки от робота

  forward(1000);
  stopMotors();
  delay(500);
  backward(1000);
  stopMotors();
}

void loop() {
}