Bắt đầu với mạch driver L298N

        +---+---+---+---+
        |IN1|IN2|ENA|   |
        +---+---+---+   |
    ↕                   | L298N
        +---+---+---+   |
        |IN3|IN4|ENB|   |
        +---+---+---+---+
         OUT1,OUT2 → Motor A
         OUT3,OUT4 → Motor B
         +12V → nguồn motor (6–35V)
         +5V  → output cấp cho Arduino (nếu dùng jumper 5V)
         GND  → mass chung

// Kết nối
// ENA → Arduino Pin 9 (PWM)
// IN1 → Pin 4, IN2 → Pin 5
// ENB → Arduino Pin 10 (PWM)
// IN3 → Pin 6, IN4 → Pin 7

const int ENA=9, IN1=4, IN2=5;
const int ENB=10, IN3=6, IN4=7;

void setup() {
  for (int p : {ENA, IN1, IN2, ENB, IN3, IN4}) pinMode(p, OUTPUT);
}

void motorA(int speed) {
  speed = constrain(speed, -255, 255);
  if (speed > 0)  { digitalWrite(IN1, HIGH); digitalWrite(IN2, LOW); }
  else if (speed < 0) { digitalWrite(IN1, LOW); digitalWrite(IN2, HIGH); speed = -speed; }
  else { digitalWrite(IN1, LOW); digitalWrite(IN2, LOW); }
  analogWrite(ENA, speed);
}

void motorB(int speed) {
  speed = constrain(speed, -255, 255);
  if (speed > 0)  { digitalWrite(IN3, HIGH); digitalWrite(IN4, LOW); }
  else if (speed < 0) { digitalWrite(IN3, LOW); digitalWrite(IN4, HIGH); speed = -speed; }
  else { digitalWrite(IN3, LOW); digitalWrite(IN4, LOW); }
  analogWrite(ENB, speed);
}

// Robot car: tiến, lùi, rẽ trái, rẽ phải
void forward(int spd=200)  { motorA(spd);  motorB(spd);  }
void backward(int spd=200) { motorA(-spd); motorB(-spd); }
void turnLeft(int spd=160) { motorA(-spd); motorB(spd);  }
void turnRight(int spd=160){ motorA(spd);  motorB(-spd); }
void stop()                { motorA(0);    motorB(0);    }

void loop() {
  forward();  delay(2000);
  turnLeft(); delay(600);
  forward();  delay(2000);
  stop();     delay(1000);
}