ESP32 Multi-Sensor Environment Monitoring: ระบบตรวจสอบสิ่งแวดล้อมครบวงจร

/*
 * ESP32 Multi-Sensor Environment Monitor
 * เชื่อมต่อ CynoIoT Platform
 * 
 * Components:
 * - DHT22: Temperature & Humidity
 * - BMP280: Pressure
 * - BH1750: Light
 * - MQ135: Air Quality
 */

#include <WiFi.h>
#include <HTTPClient.h>
#include <DHT.h>
#include <Adafruit_BMP280.h>
#include <Wire.h>
#include <BH1750.h>

// ===== WiFi Credentials =====
const char* ssid = "YOUR_WIFI_SSID";
const char* password = "YOUR_WIFI_PASSWORD";

// ===== CynoIoT Configuration =====
const char* cynoiot_server = "api.cynoiot.com"; // แก้ไขตาม server จริง
const String device_id = "YOUR_DEVICE_ID";
const String api_key = "YOUR_API_KEY";

// ===== Sensor Configuration =====
// DHT22 - Temperature & Humidity
#define DHTPIN 4
#define DHTTYPE DHT22
DHT dht(DHTPIN, DHTTYPE);

// BMP280 - Pressure (I2C)
Adafruit_BMP280 bmp;
// I2C: SDA = GPIO 21, SCL = GPIO 22

// BH1750 - Light (I2C)
BH1750 lightMeter;

// MQ135 - Air Quality (Analog)
#define MQ135_PIN 34

// ===== Timing Configuration =====
unsigned long lastReadTime = 0;
const long readInterval = 5000; // อ่านทุก 5 วินาที

unsigned long lastUploadTime = 0;
const long uploadInterval = 30000; // อัปโหลดทุก 30 วินาที

// ===== Data Storage =====
struct SensorData {
  float temperature;
  float humidity;
  float pressure;
  float light;
  int airQuality;
  bool valid;
};

SensorData currentData;

void setup() {
  Serial.begin(115200);
  Serial.println("\n=== ESP32 Environment Monitor ===");
  
  // Initialize WiFi
  setupWiFi();
  
  // Initialize Sensors
  setupSensors();
  
  Serial.println("Setup complete! Starting monitoring...");
}

void loop() {
  unsigned long currentTime = millis();
  
  // อ่านเซ็นเซอร์ทุก 5 วินาที
  if (currentTime - lastReadTime >= readInterval) {
    lastReadTime = currentTime;
    readSensors();
    printData();
  }
  
  // อัปโหลดไป CynoIoT ทุก 30 วินาที
  if (currentTime - lastUploadTime >= uploadInterval) {
    lastUploadTime = currentTime;
    if (currentData.valid) {
      uploadData();
    } else {
      Serial.println("Skipping upload - invalid data");
    }
  }
}

// ===== WiFi Setup =====
void setupWiFi() {
  Serial.print("Connecting to WiFi");
  
  WiFi.begin(ssid, password);
  
  int attempts = 0;
  while (WiFi.status() != WL_CONNECTED && attempts < 20) {
    delay(500);
    Serial.print(".");
    attempts++;
  }
  
  if (WiFi.status() == WL_CONNECTED) {
    Serial.println("\nWiFi connected!");
    Serial.print("IP address: ");
    Serial.println(WiFi.localIP());
  } else {
    Serial.println("\nFailed to connect to WiFi");
  }
}

// ===== Sensor Setup =====
void setupSensors() {
  Serial.println("Initializing sensors...");
  
  // DHT22
  dht.begin();
  Serial.println("✓ DHT22 initialized");
  
  // BMP280
  if (bmp.begin(0x76)) {
    Serial.println("✓ BMP280 initialized (0x76)");
  } else if (bmp.begin(0x77)) {
    Serial.println("✓ BMP280 initialized (0x77)");
  } else {
    Serial.println("✗ BMP280 not found!");
  }
  
  // BH1750
  Wire.begin();
  if (lightMeter.begin(BH1750::ONE_TIME_HIGH_RES_MODE)) {
    Serial.println("✓ BH1750 initialized");
  } else {
    Serial.println("✗ BH1750 not found!");
  }
  
  // MQ135 (Analog - no init needed)
  pinMode(MQ135_PIN, INPUT);
  Serial.println("✓ MQ135 initialized");
  
  Serial.println("All sensors initialized!");
}

// ===== Read All Sensors =====
void readSensors() {
  // DHT22 - Temperature & Humidity
  float temp = dht.readTemperature();
  float hum = dht.readHumidity();
  
  // BMP280 - Pressure
  float press = bmp.readPressure() / 100.0F; // hPa
  
  // BH1750 - Light
  float lux = lightMeter.readLightLevel();
  
  // MQ135 - Air Quality
  int airQ = analogRead(MQ135_PIN);
  
  // Validate data
  currentData.temperature = temp;
  currentData.humidity = hum;
  currentData.pressure = press;
  currentData.light = lux;
  currentData.airQuality = airQ;
  
  // Check if valid
  currentData.valid = !isnan(temp) && !isnan(hum) && !isnan(press) && !isnan(lux);
  
  if (!currentData.valid) {
    Serial.println("Warning: Some sensor readings are invalid!");
  }
}

// ===== Print Data to Serial =====
void printData() {
  Serial.println("\n=== Sensor Readings ===");
  Serial.printf("Temperature: %.2f °C\n", currentData.temperature);
  Serial.printf("Humidity: %.2f %%\n", currentData.humidity);
  Serial.printf("Pressure: %.2f hPa\n", currentData.pressure);
  Serial.printf("Light: %.2f Lux\n", currentData.light);
  Serial.printf("Air Quality: %d PPM\n", currentData.airQuality);
  
  // Air quality status
  if (currentData.airQuality < 200) {
    Serial.println("Air Quality: GOOD");
  } else if (currentData.airQuality < 400) {
    Serial.println("Air Quality: MODERATE");
  } else {
    Serial.println("Air Quality: POOR");
  }
  Serial.println("========================\n");
}

// ===== Upload to CynoIoT =====
void uploadData() {
  if (WiFi.status() != WL_CONNECTED) {
    Serial.println("WiFi not connected - skipping upload");
    return;
  }
  
  HTTPClient http;
  
  // Build JSON payload
  String jsonPayload = "{";
  jsonPayload += "\"temperature\":" + String(currentData.temperature) + ",";
  jsonPayload += "\"humidity\":" + String(currentData.humidity) + ",";
  jsonPayload += "\"pressure\":" + String(currentData.pressure) + ",";
  jsonPayload += "\"light\":" + String(currentData.light) + ",";
  jsonPayload += "\"air_quality\":" + String(currentData.airQuality);
  jsonPayload += "}";
  
  // Send HTTP POST
  String url = "http://" + String(cynoiot_server) + "/api/devices/" + device_id + "/data";
  
  http.begin(url);
  http.addHeader("Content-Type", "application/json");
  http.addHeader("X-API-Key", api_key);
  
  int httpResponseCode = http.POST(jsonPayload);
  
  if (httpResponseCode > 0) {
    Serial.print("Upload successful. Response code: ");
    Serial.println(httpResponseCode);
  } else {
    Serial.print("Upload failed. Error code: ");
    Serial.println(httpResponseCode);
  }
  
  http.end();
}

// ฟังก์ชันสอบเทียบ MQ135 (เพิ่มลงในโค้ดหลัก)
void calibrateMQ135() {
  Serial.println("Calibrating MQ135...");
  Serial.println("Please ensure the sensor is in fresh air");
  
  int sensorValue = 0;
  int samples = 100;
  
  // อ่านค่าเฉลี่ย 100 ครั้ง
  for (int i = 0; i < samples; i++) {
    sensorValue += analogRead(MQ135_PIN);
    delay(10);
  }
  
  sensorValue = sensorValue / samples;
  
  Serial.print("Baseline value: ");
  Serial.println(sensorValue);
  
  // ค่า R0 = Rs ในอากาศสะอาด (จะใช้ในการคำนวณ)
  float r0 = (float)sensorValue;
  // ... เก็บ r0 ไว้ใช้ในการคำนวณค่า PPM จริง
  
  Serial.println("Calibration complete!");
}

// แก้ไขใน readSensors()
float tempOffset = 0.0; // ปรับค่านี้หากค่าที่ได้สูง/ต่ำไป
float temp = dht.readTemperature() + tempOffset;

// เพิ่มบรรทัดนี้ใน setup()
// ตั้งเวลาให้ตื่นทุก 5 นาที (300 วินาที)
esp_sleep_enable_timer_wakeup(300 * 1000000);

// ใน loop() - อ่านเซ็นเซอร์และอัปโหลด แล้วเข้า Deep Sleep
void loop() {
  readSensors();
  
  if (WiFi.status() != WL_CONNECTED) {
    WiFi.begin(ssid, password);
    delay(2000); // รอให้เชื่อมต่อ
  }
  
  if (currentData.valid) {
    uploadData();
  }
  
  Serial.println("Entering deep sleep...");
  Serial.flush();
  
  esp_deep_sleep_start(); // จะตื่นเมื่อครบเวลาที่ตั้งไว้
}