without_functions.ino

// Include the Servo library
#include <Servo.h>

// --- Pin Definitions (as variables) ---
// L298N Motor Driver Pins
const int enA = 7;            // Enable A (Left Motor Speed)
const int leftMotorIn1 = 6;   // IN1 (Left Motor)
const int leftMotorIn2 = 5;   // IN2 (Left Motor)
const int rightMotorIn1 = 4;  // IN3 (Right Motor)
const int rightMotorIn2 = 3;  // IN4 (Right Motor)
const int enB = 2;            // Enable B (Right Motor Speed)

// Ultrasonic Sensor Pins
const int trigPin = 9;
const int echoPin = 8;

// Servo Motor Pin
const int servoPin = 10;

// --- STUDENT CALIBRATION VARIABLES ---
int motorSpeed = 180;     // General speed for forward/turning (0-255)
int stopDistance = 20;    // How close to get to a wall before stopping (cm).
int turnDelay = 450;      // How long to run motors for a 90-degree turn (ms)
int servoWaitDelay = 400; // How long to wait for servo to move (ms)
int servoLeftAngle = 130;
int servoCenterAngle = 90;
int servoRightAngle = 50; 

// Create our servo object
Servo headServo;

void setup() {
  Serial.begin(9600);

  // Set all motor pins as OUTPUTs
  pinMode(enA, OUTPUT);
  pinMode(leftMotorIn1, OUTPUT);
  pinMode(leftMotorIn2, OUTPUT);
  pinMode(enB, OUTPUT);
  pinMode(rightMotorIn1, OUTPUT);
  pinMode(rightMotorIn2, OUTPUT);

  // Set sensor pins
  pinMode(trigPin, OUTPUT);
  pinMode(echoPin, INPUT);

  // Attach the servo
  headServo.attach(servoPin);
  headServo.write(servoCenterAngle); // Start facing center

  Serial.println("Procedural Reactive Avoider - Ready.");
  Serial.println("Ensure calibration variables are set!");
  delay(1000);
}


void loop() {

  // --- "Get Distance" Snippet ---
  long duration, frontDistance;
  digitalWrite(trigPin, LOW);
  delayMicroseconds(2);
  digitalWrite(trigPin, HIGH);
  delayMicroseconds(10);
  digitalWrite(trigPin, LOW);
  duration = pulseIn(echoPin, HIGH);
  frontDistance = (duration * 0.0343) / 2; // Calculate distance in cm

  // IF: The path in front is clear
  if (frontDistance > stopDistance) {
  
    // --- "Move Forward" Snippet ---
    digitalWrite(leftMotorIn1, HIGH);
    digitalWrite(leftMotorIn2, LOW);
    analogWrite(enA, motorSpeed);
    digitalWrite(rightMotorIn1, HIGH);
    digitalWrite(rightMotorIn2, LOW);
    analogWrite(enB, motorSpeed);
  
  }
  else {
    
    // --- "Stop Motors" Snippet ---
    digitalWrite(leftMotorIn1, LOW);
    digitalWrite(leftMotorIn2, LOW);
    analogWrite(enA, 0);
    digitalWrite(rightMotorIn1, LOW);
    digitalWrite(rightMotorIn2, LOW);
    analogWrite(enB, 0);

    // 2a. Look Right
    headServo.write(servoRightAngle);
    delay(servoWaitDelay);
    
    // --- "Get Distance" Snippet ---
    long rightDuration, rightDistance;
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);
    rightDuration = pulseIn(echoPin, HIGH);
    rightDistance = (rightDuration * 0.0343) / 2;
    
    // --- "Get Distance" Snippet ---
    long leftDuration, leftDistance;
    digitalWrite(trigPin, LOW);
    delayMicroseconds(2);
    digitalWrite(trigPin, HIGH);
    delayMicroseconds(10);
    digitalWrite(trigPin, LOW);
    leftDuration = pulseIn(echoPin, HIGH);
    leftDistance = (leftDuration * 0.0343) / 2;
    
    // 2c. Make the decision
    if (leftDistance > rightDistance) {  
    
      // --- "Turn Left" Snippet ---
      digitalWrite(leftMotorIn1, LOW);
      digitalWrite(leftMotorIn2, HIGH);
      analogWrite(enA, motorSpeed);
      digitalWrite(rightMotorIn1, HIGH);
      digitalWrite(rightMotorIn2, LOW);
      analogWrite(enB, motorSpeed);
      
    } else {      
    
      // --- "Turn Right" Snippet ---
      digitalWrite(leftMotorIn1, HIGH);
      digitalWrite(leftMotorIn2, LOW);
      analogWrite(enA, motorSpeed);
      digitalWrite(rightMotorIn1, LOW);
      digitalWrite(rightMotorIn2, HIGH);
      analogWrite(enB, motorSpeed);
      
    }
    
    // --- "Stop Motors" Snippet ---
    digitalWrite(leftMotorIn1, LOW);
    digitalWrite(leftMotorIn2, LOW);
    analogWrite(enA, 0);
    digitalWrite(rightMotorIn1, LOW);
    digitalWrite(rightMotorIn2, LOW);
    analogWrite(enB, 0);
    
  }
  
}