ESP32 WiFi Weather Station with OLED Display

/*********************************************************************
 * ESP32 WiFi Weather Station with OLED Display
 * 
 * Displays: Temperature, Humidity, Pressure, Altitude
 * Hardware: ESP32, BME280 Sensor, SSD1306 OLED 128x64
 * 
 * Libraries Required:
 * - Adafruit BME280 (install from Library Manager)
 * - Adafruit GFX Library
 * - Adafruit SSD1306
 * 
 * I2C Pins: SDA=GPIO 21, SCL=GPIO 22
 *********************************************************************/

#include 
#include 
#include 
#include 

// ============== DISPLAY CONFIGURATION ==============
#define SCREEN_WIDTH 128
#define SCREEN_HEIGHT 64
#define OLED_RESET -1

Adafruit_SSD1306 display(SCREEN_WIDTH, SCREEN_HEIGHT, &Wire, OLED_RESET);

// ============== SENSOR CONFIGURATION ==============
#define SEALEVELPRESSURE_HPA (1013.25)

Adafruit_BME280 bme280;

// ============== BAUD RATE ==============
#define BAUD_RATE 115200

// ============== DISPLAY UPDATE INTERVAL ==============
#define UPDATE_INTERVAL 2000  // milliseconds
unsigned long lastUpdate = 0;

// ============== SETUP ==============
void setup() {
  Serial.begin(BAUD_RATE);
  Serial.println(F("\n======================================"));
  Serial.println(F("ESP32 WiFi Weather Station Starting..."));
  Serial.println(F("======================================"));
  
  // Initialize OLED Display
  if (!display.begin(SSD1306_SWITCHCAPVCC, 0x3C)) {
    Serial.println(F("SSD1306 allocation failed"));
    while (true); // Halt
  }
  
  // Initialize BME280 Sensor
  if (!bme280.begin(0x76)) {  // Try 0x76 first (common address)
    Serial.println(F("Could not find BME280 sensor at 0x76, trying 0x77..."));
    if (!bme280.begin(0x77)) {
      Serial.println(F("Could not find BME280 sensor!"));
      while (true);
    }
  }
  
  Serial.println(F("BME280 initialized successfully!"));
  
  // Clear display and show startup message
  display.clearDisplay();
  display.display();
  delay(1000);
  
  // Test display
  displayText("Weather Station", "Initializing...", 1000);
  displayText("Weather Station", "Sensor OK!", 500);
  
  Serial.println(F("\nSetup complete!"));
  Serial.println(F("Reading sensor data...\n"));
}

// ============== MAIN LOOP ==============
void loop() {
  // Update display every 2 seconds
  if (millis() - lastUpdate > UPDATE_INTERVAL) {
    lastUpdate = millis();
    updateDisplay();
  }
}

// ============== DISPLAY FUNCTION ==============
void updateDisplay() {
  // Read sensor data
  float temperature = bme280.readTemperature();    // Celsius
  float humidity = bme280.readHumidity();         // Percentage
  float pressure = bme280.readPressure() / 100.0F; // hPa
  float altitude = bme280.readAltitude(SEALEVELPRESSURE_HPA); // Meters
  
  // Print to Serial Monitor
  Serial.println(F("========== WEATHER DATA =========="));
  Serial.print(F("Temperature: ")); Serial.print(temperature); Serial.println(F(" °C"));
  Serial.print(F("Humidity: ")); Serial.print(humidity); Serial.println(F(" %"));
  Serial.print(F("Pressure: ")); Serial.print(pressure); Serial.println(F(" hPa"));
  Serial.print(F("Altitude: ")); Serial.print(altitude); Serial.println(F(" m"));
  Serial.println(F("================================\n"));
  
  // Update OLED Display
  display.clearDisplay();
  display.setTextSize(1);
  display.setTextColor(SSD1306_WHITE);
  
  // Title
  display.setCursor(25, 0);
  display.println(F("WEATHER"));
  display.setCursor(30, 8);
  display.println(F("STATION"));
  
  // Divider line
  display.drawLine(0, 18, 128, 18, SSD1306_WHITE);
  
  // Weather data
  display.setTextSize(1);
  display.setCursor(0, 24);
  display.print(F("Temp: ")); display.print(temperature, 1); display.println(F(" C"));
  
  display.setCursor(0, 34);
  display.print(F("Hum:  ")); display.print(humidity, 0); display.println(F(" %"));
  
  display.setCursor(0, 44);
  display.print(F("Pres: ")); display.print(pressure, 0); display.println(F(" hPa"));
  
  display.setCursor(0, 54);
  display.print(F("Alt:  ")); display.print(altitude, 0); display.println(F(" m"));
  
  display.display();
}

// ============== HELPER FUNCTION ==============
void displayText(String line1, String line2, int delayMs) {
  display.clearDisplay();
  display.setTextSize(2);
  display.setTextColor(SSD1306_WHITE);
  display.setCursor(10, 15);
  display.println(line1);
  display.setCursor(25, 35);
  display.setTextSize(1);
  display.println(line2);
  display.display();
  delay(delayMs);
}

// ============== END OF CODE ==============

// Add WiFi configuration
const char* wifi_ssid = "YOUR_WIFI_NAME";
const char* wifi_password = "YOUR_WIFI_PASSWORD";

// Add to setup():
WiFi.begin(wifi_ssid, wifi_password);
Serial.print("Connecting to WiFi");
while (WiFi.status() != WL_CONNECTED) {
  delay(500);
  Serial.print(".");
}
Serial.println(" Connected!");

// Send to ThingSpeak (example)
if (WiFi.status() == WL_CONNECTED) {
  HTTPClient http;
  String url = "https://api.thingspeak.com/update?api_key=YOUR_API_KEY";
  url += "&field1=" + String(temperature);
  url += "&field2=" + String(humidity);
  url += "&field3=" + String(pressure);
  http.begin(url);
  http.GET();
  http.end();
}