const byte IN1 = 6;
const byte IN2 = 7;
const byte ENA = 5;

void setup() {
    pinMode(IN1, OUTPUT);
    pinMode(IN2, OUTPUT);
    pinMode(ENA, OUTPUT);
    digitalWrite(IN1, HIGH);
    digitalWrite(IN2, LOW);
    Serial.begin(9600);
}

void loop() {
    Serial.println("Begin!");
    analogWrite(ENA, 150);
    delay(1000);
    Serial.println("Stop!");
    analogWrite(ENA, 0);
    delay(1000);
}