#define BLYNK_TEMPLATE_ID "TMPL6FIf8b1oa"
#define BLYNK_TEMPLATE_NAME "tewgwsb"
#define BLYNK_AUTH_TOKEN "bvekCkco2myGQpdvucWh2yb9yqUa80Tm"

#define BLYNK_PRINT Serial

#include <WiFi.h>
#include <BlynkSimpleEsp32.h>
#include <Wire.h>
#include <Adafruit_GFX.h>
#include <Adafruit_SSD1306.h>

// WiFi
const char* WIFI_SSID = "Wokwi-GUEST";
const char* WIFI_PASS = "";

// OLED
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, -1);

// Ultrasonic
#define TRIG 14
#define ECHO 33

// RGB
#define RED   27
#define GREEN 26
#define BLUE  25

long duration;
float distance;

void setup() {
  Serial.begin(115200);

  pinMode(TRIG, OUTPUT);
  pinMode(ECHO, INPUT);

  pinMode(RED, OUTPUT);
  pinMode(GREEN, OUTPUT);
  pinMode(BLUE, OUTPUT);

  // ✅ บังคับระบุขา SDA=21, SCL=22 (ค่า default ESP32)
  Wire.begin(21, 22);

  // ✅ เริ่มต้น OLED ที่ address 0x3C
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    for (;;);
  }

  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(0, 0);
  display.println("Natakorn 15297");
  display.display();
  delay(2000);

  // ✅ เชื่อม WiFi แบบ debug
  Serial.print("Connecting to WiFi: ");
  Serial.println(WIFI_SSID);
  WiFi.begin(WIFI_SSID, WIFI_PASS);

  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\n✅ WiFi Connected!");
  Serial.print("IP Address: ");
  Serial.println(WiFi.localIP());

  // ✅ เชื่อม Blynk
  Blynk.begin(BLYNK_AUTH_TOKEN, WIFI_SSID, WIFI_PASS);
}

void loop() {
  Blynk.run();

  // Ultrasonic
  digitalWrite(TRIG, LOW);
  delayMicroseconds(2);
  digitalWrite(TRIG, HIGH);
  delayMicroseconds(10);
  digitalWrite(TRIG, LOW);

  duration = pulseIn(ECHO, HIGH);
  distance = duration * 0.034 / 2;

  // ✅ แสดงผลบน OLED
  display.clearDisplay();
  display.setTextSize(1);
  display.setCursor(0, 0);
  display.println("Natakorn 15297");

  display.setTextSize(2);
  display.setCursor(0, 20);
  display.print("Dist:");
  display.print(distance, 1);
  display.println(" cm");
  display.display();

  // Blynk
  Blynk.virtualWrite(V0, distance);

  // RGB LED
  if (distance < 20) {
    digitalWrite(RED, HIGH);
    digitalWrite(GREEN, HIGH);
    digitalWrite(BLUE, HIGH);
  } else if (distance >= 20 && distance <= 30) {
    digitalWrite(RED, HIGH);
    digitalWrite(GREEN, HIGH);
    digitalWrite(BLUE, HIGH);
    delay(200);
    digitalWrite(RED, LOW);
    digitalWrite(GREEN, LOW);
    digitalWrite(BLUE, LOW);
    delay(200);
  } else {
    digitalWrite(RED, LOW);
    digitalWrite(GREEN, LOW);
    digitalWrite(BLUE, LOW);
  }

  delay(100);
}
.