Split View: 개발자를 위한 전자제어 입문 — 아두이노부터 AI 로봇까지

[Stage 1] Arduino Basics (This article)
    └── LED, Buttons, Sensors, Servo Motors
[Stage 2] ESP32 IoT
    └── WiFi, MQTT, Web Dashboard
[Stage 3] Raspberry Pi + Camera
    └── Computer Vision, Edge AI
[Stage 4] ROS 2 Robotics
    └── Autonomous Driving, Manipulators
[Stage 5] AI + Hardware Fusion
    └── Voice-Controlled Robot, Smart Home

Digital: 0 or 1 (ON/OFF)
  → LED control, button reading
  → Arduino: digitalRead(), digitalWrite()

Analog: Continuous values 0~1023
  → Temperature sensor, light sensor
  → Arduino: analogRead(), analogWrite() (PWM)

V = I × R

V (Voltage) = 5V (Arduino default)
R (Resistance) = 220Ω (LED protection)
I (Current) = 5V / 220Ω = 22.7mA ✅ (Safe range for LED)

Arduino Uno R4:
  Digital Pins: D0~D13 (Input/Output)
  Analog Pins: A0~A5 (Input)
  PWM Pins: D3, D5, D6, D9, D10, D11 (Pseudo-analog output)
  Power: 5V, 3.3V, GND

Arduino D13 ──[220Ω]──[LED(+)]──[LED(-)]── GND

// Blink — The Hello World of Electronics
void setup() {
    pinMode(13, OUTPUT);  // Set D13 as output
}

void loop() {
    digitalWrite(13, HIGH);  // LED ON
    delay(1000);             // Wait 1 second
    digitalWrite(13, LOW);   // LED OFF
    delay(1000);             // Wait 1 second
}

# MicroPython (runs on ESP32)
from machine import Pin
import time

led = Pin(13, Pin.OUT)

while True:
    led.value(1)   # ON
    time.sleep(1)
    led.value(0)   # OFF
    time.sleep(1)

const int buttonPin = 2;
const int ledPin = 13;
int buttonState = 0;

void setup() {
    pinMode(ledPin, OUTPUT);
    pinMode(buttonPin, INPUT_PULLUP);  // Use internal pull-up resistor
}

void loop() {
    buttonState = digitalRead(buttonPin);

    if (buttonState == LOW) {  // Button pressed (LOW because of PULLUP)
        digitalWrite(ledPin, HIGH);
    } else {
        digitalWrite(ledPin, LOW);
    }
}

#include <DHT.h>

#define DHTPIN 2
#define DHTTYPE DHT11

DHT dht(DHTPIN, DHTTYPE);

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

void loop() {
    float humidity = dht.readHumidity();
    float temperature = dht.readTemperature();

    Serial.print("Temperature: ");
    Serial.print(temperature);
    Serial.print("°C / Humidity: ");
    Serial.print(humidity);
    Serial.println("%");

    delay(2000);
}

#include <Servo.h>

Servo myServo;

void setup() {
    myServo.attach(9);  // Connect servo to D9
}

void loop() {
    // Sweep 0° → 180°
    for (int angle = 0; angle <= 180; angle += 10) {
        myServo.write(angle);
        delay(50);
    }
    // Sweep 180° → 0°
    for (int angle = 180; angle >= 0; angle -= 10) {
        myServo.write(angle);
        delay(50);
    }
}

const int ledPin = 9;  // PWM pin

void setup() {
    pinMode(ledPin, OUTPUT);
}

void loop() {
    // Fade in
    for (int brightness = 0; brightness <= 255; brightness += 5) {
        analogWrite(ledPin, brightness);
        delay(30);
    }
    // Fade out
    for (int brightness = 255; brightness >= 0; brightness -= 5) {
        analogWrite(ledPin, brightness);
        delay(30);
    }
}

[Arduino Sensors] → [ESP32 WiFi] → [K8s MQTT Broker]
                                        ↓
                               [AI Inference (GPU Server)]
                                        ↓
                               [Control Commands → Motors/LEDs]