First Steps in Code: Arduino IDE & Wokwi Setup, Blink, Serial, I/O & Sensors

// 1. GLOBAL SCOPE: Pin definitions, variables, and libraries
const int LED_PIN = 13;

void setup() {
  // 2. SETUP: Runs ONCE when power turns on or reset is pressed
  pinMode(LED_PIN, OUTPUT);
  Serial.begin(115200);
  Serial.println("Robot Controller Initialized!");
}

void loop() {
  // 3. MAIN LOOP: Repeats continuously as fast as possible
  digitalWrite(LED_PIN, HIGH); // Turn LED ON (5V)
  delay(500);                  // Wait 500 milliseconds
  digitalWrite(LED_PIN, LOW);  // Turn LED OFF (0V)
  delay(500);                  // Wait 500 milliseconds
}

const int BUTTON_PIN = 2; // Button wired between Pin 2 and GND
const int LED_PIN = 13;

void setup() {
  pinMode(BUTTON_PIN, INPUT_PULLUP); // Button unpressed = HIGH, pressed = LOW
  pinMode(LED_PIN, OUTPUT);
  Serial.begin(115200);
}

void loop() {
  int buttonState = digitalRead(BUTTON_PIN);
  
  if (buttonState == LOW) { // Button is pressed!
    digitalWrite(LED_PIN, HIGH);
    Serial.println("Bumper Switch TRIGGERED: Obstacle Hit!");
  } else {
    digitalWrite(LED_PIN, LOW);
  }
}

const int POT_PIN = A0;  // Center pin of 10k potentiometer
const int MOTOR_PWM = 9; // PWM pin on Arduino Uno (~9)

void setup() {
  pinMode(MOTOR_PWM, OUTPUT);
  Serial.begin(115200);
}

void loop() {
  int sensorValue = analogRead(POT_PIN); // Reads 0 to 1023
  
  // Map 10-bit input (0-1023) to 8-bit PWM speed (0-255)
  int speed = map(sensorValue, 0, 1023, 0, 255);
  
  analogWrite(MOTOR_PWM, speed); // Generates PWM signal for motor driver
  
  Serial.print("Raw Sensor: ");
  Serial.print(sensorValue);
  Serial.print(" -> Calculated Speed: ");
  Serial.println(speed);
  delay(50);
}

Serial.print("Distance: ");
Serial.print(distanceCm);
Serial.print(" cm | State: ");
Serial.println(robotState);

#include <Servo.h>

Servo scanRadar; // Create servo object to control ultrasonic sensor turret

void setup() {
  scanRadar.attach(9); // Connect SG90 signal wire (orange/yellow) to Pin 9
}

void loop() {
  // Sweep from 0 degrees to 180 degrees
  for (int angle = 0; angle <= 180; angle += 15) {
    scanRadar.write(angle);
    delay(100);
  }
  
  // Sweep back from 180 degrees to 0 degrees
  for (int angle = 180; angle >= 0; angle -= 15) {
    scanRadar.write(angle);
    delay(100);
  }
}