Controlling a DC Motor with an L298N Driver

An Arduino pin can't power a motor directly — it can't supply enough current, and it can't reverse the flow. An L298N H-bridge solves both: the Arduino sends low-power control signals, and the driver switches the motor's own battery to run it forwards, backwards and at any speed. This is the core building block of every wheeled robot.

中级

1-2 hours

说明

Wire the driver, motor and battery

Push the L298N's control header into the breadboard. From the Arduino, jumper pin 8 to IN1, pin 9 to IN2, and pin 10 to ENA. Connect the DC motor's two wires to the OUT1/OUT2 screw terminals, and a 4×AA battery pack to the +12V and GND motor terminals. IMPORTANT: join all the grounds together — Arduino GND, driver GND and battery GND — or the motor won't run.

此步骤所需材料：

Arduino Uno R3 SMD1 个

Full-Bridge Motor Driver Dual - L298N1 个

Hobby Motor - Gear1 个

Battery Holder - 4xAA Square Terminated1 个

Breadboard - Classic1 个

Jumper Wires Premium M/M 20 AWG - 15.5 cm1 包

Connect and open the IDE

Plug the Arduino into your computer with the USB cable, open the Arduino IDE, and select Arduino Uno and its serial port. Leave the motor battery switched off until the code is uploaded.

此步骤所需材料：

SparkFun Cerberus USB Cable - 1.8 meter1 个

所需工具：

Computer with Arduino IDE

Upload the motor sketch

Paste this sketch and upload, then switch on the battery. The motor runs forward, stops, reverses, and stops — on a loop.

dc_motor_l298n.inoarduino

// Control a DC motor's speed and direction with an L298N H-bridge.
// L298N IN1 -> pin 8, IN2 -> pin 9, ENA (PWM speed) -> pin 10.
// The motor is powered by the battery pack through the driver; all grounds are joined.

const int IN1 = 8;
const int IN2 = 9;
const int ENA = 10;   // PWM speed pin (0-255)

void setup() {
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(ENA, OUTPUT);
}

void loop() {
  // forward at medium speed
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  analogWrite(ENA, 180);
  delay(2000);

  // stop
  analogWrite(ENA, 0);
  delay(1000);

  // reverse at full speed
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  analogWrite(ENA, 255);
  delay(2000);

  // stop
  analogWrite(ENA, 0);
  delay(1000);
}

Test and control it

Watch the motor go forward, stop, reverse. IN1/IN2 set the direction (swap which is HIGH to flip it); the number in analogWrite(ENA, ...) sets the speed from 0 (off) to 255 (full). If the motor doesn't spin, check that all three grounds are joined and the battery is on.

Make it a robot

The L298N drives TWO motors. Wire a second motor to OUT3/OUT4 and control it with IN3, IN4 and ENB on three more Arduino pins. Two motors on a chassis with wheels gives you a robot base you can drive — turn by running the wheels at different speeds or directions.