1. Arduino Uno R3.
2. Motor Driver Shield or Driver IC (e.g., L298N, L293D, or a motor driver shield).
3. Two DC Motors.
4. Power Supply (Battery).
5. Wires and Connectors.
6. Optional: Sensors (e.g., Ultrasonic for obstacle detection), LEDs, and other accessories.

1. Stack the Motor Driver Shield onto the Arduino Uno R3.
2. Connect the DC Motors to the motor outputs on the shield:
   • Connect Motor 1's wires to M1 outputs.
   • Connect Motor 2's wires to M2 outputs.
3. Power Connections:
   • Make sure the shield’s power requirements match your battery. Connect the battery’s positive lead to the Vin terminal on the motor shield and the negative lead to the GND terminal.
4. Pin Assignments:
   • On a motor driver shield, pins are often predefined. For example, a commonly used shield might assign pins D3, D5, D6, and D9 for motor control.
5. Other Elements (Sensors or LEDs):
   • For ultrasonic sensor (HC-SR04):
     • VCC to +5V.
     • GND to GND.
     • Trig to, for example, D10.
     • Echo to, for example, D11.

1. Motor Connections:
   • Connect Motor 1’s wires to the OUT1 and OUT2 terminals on the L298N.
   • Connect Motor 2’s wires to the OUT3 and OUT4 terminals.
2. Arduino to L298N Connections:
   • Connect ENA (Enable A) to D10 on the Arduino.
   • Connect IN1 to D6.
   • Connect IN2 to D7.
   • Connect IN3 to D8.
   • Connect IN4 to D9.
   • Connect ENB (Enable B) to D11.
3. Power Connections:
   • Make sure the L298N module is powered properly. Connect the battery's positive lead to the 12V terminal on the L298N and the negative lead to the GND.
4. Powering the Arduino:
   • If the battery is in a suitable range (e.g., a 9V battery), you can use it to power the Arduino via the Vin pin.

Cpp
// Define motor pins
#define ENA 10
#define IN1 6
#define IN2 7
#define IN3 8
#define IN4 9
#define ENB 11

void setup() {
  // Set all motor control pins to output
  pinMode(ENA, OUTPUT);
  pinMode(IN1, OUTPUT);
  pinMode(IN2, OUTPUT);
  pinMode(IN3, OUTPUT);
  pinMode(IN4, OUTPUT);
  pinMode(ENB, OUTPUT);
}

void loop() {
  // Move forward
  digitalWrite(IN1, HIGH);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, HIGH);
  digitalWrite(IN4, LOW);
  analogWrite(ENA, 255); // Full speed
  analogWrite(ENB, 255);
  delay(2000);

  // Move backward
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, HIGH);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, HIGH);
  analogWrite(ENA, 255);
  analogWrite(ENB, 255);
  delay(2000);

  // Stop
  digitalWrite(IN1, LOW);
  digitalWrite(IN2, LOW);
  digitalWrite(IN3, LOW);
  digitalWrite(IN4, LOW);
  analogWrite(ENA, 0);
  analogWrite(ENB, 0);
  delay(1000);
}

1. Motor Driver Shield:
   • Stack the shield onto Arduino.
   • Connect motors to M1 and M2.
   • Connect power to Vin and GND.
2. L298N Motor Driver:
   • Connect Motor 1 to OUT1 and OUT2.
   • Connect Motor 2 to OUT3 and OUT4.
   • Connect ENA to D10, IN1 to D6, IN2 to D7, IN3 to D8, IN4 to D9, ENB to D11.
   • Connect power to 12V and GND.