บทความ: สร้างเครื่องวัดคุณภาพอากาศด้วย ESP32 ตรวจจับ PM2.5 และ CO2

#include <Wire.h>
#include <Adafruit_SCD30.h>
#include <Adafruit_SCD4x.h>
#include "PMS.h"
#include <WiFi.h>
#include <HTTPClient.h>

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

// ตั้งค่า CynoIoT
const char* deviceToken = "YOUR_DEVICE_TOKEN";
const char* cynoiotUrl = "https://api.cynoiot.com/v1/devices/data";

// Sensor objects
Adafruit_SCD30 scd30;
Adafruit_SCD4x scd4x;
PMS pms(Serial2);
PMS::DATA pmsData;

// Timing variables
unsigned long lastSendTime = 0;
const long sendInterval = 30000; // ส่งทุก 30 วินาที

void setup() {
  Serial.begin(115200);
  
  // เชื่อมต่อ WiFi
  WiFi.begin(ssid, password);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
  }
  Serial.println("\nWiFi connected");
  
  // เริ่มต้น SCD30/SCD4x sensor
  if (!scd30.begin() && !scd4x.begin()) {
    Serial.println("Failed to find SCD30/SCD4x chip");
    while (1) { delay(10); }
  }
  
  // เริ่มต้น PMS5003 sensor
  Serial2.begin(9600, SERIAL_8N1, 16, 17); // RX2=GPIO16, TX2=GPIO17
  
  Serial.println("Air Quality Monitor initialized");
}

void loop() {
  // อ่านค่า PM2.5 และ PM10
  if (pms.read(pmsData)) {
    float pm25 = pmsData.PM_AE_UG_2_5;
    float pm10 = pmsData.PM_AE_UG_10_0;
    
    // อ่านค่า CO2, Temperature, Humidity
    float co2 = 0, temp = 0, hum = 0;
    
    if (scd30.dataReady()) {
      scd30.read();
      co2 = scd30.CO2;
      temp = scd30.temperature;
      hum = scd30.relative_humidity;
    } else if (scd4x.readMeasurement()) {
      co2 = scd4x.CO2;
      temp = scd4x.temperature;
      hum = scd4x.relativeHumidity;
    }
    
    // คำนวณ AQI จาก PM2.5
    int aqi = calculateAQI(pm25);
    
    // แสดงผลใน Serial Monitor
    Serial.printf("PM2.5: %.1f µg/m³, PM10: %.1f µg/m³\n", pm25, pm10);
    Serial.printf("CO2: %.0f ppm, Temp: %.1f°C, Hum: %.0f%%\n", co2, temp, hum);
    Serial.printf("AQI: %d\n", aqi);
    
    // ส่งข้อมูลไป CynoIoT ทุก 30 วินาที
    if (millis() - lastSendTime >= sendInterval) {
      sendToCynoIoT(pm25, pm10, co2, aqi, temp, hum);
      lastSendTime = millis();
    }
  }
  
  delay(1000);
}

// คำนวณ AQI จากค่า PM2.5
int calculateAQI(float pm25) {
  if (pm25 <= 12.0) return map(pm25, 0, 12, 0, 50);
  else if (pm25 <= 35.4) return map(pm25, 12.1, 35.4, 51, 100);
  else if (pm25 <= 55.4) return map(pm25, 35.5, 55.4, 101, 150);
  else if (pm25 <= 150.4) return map(pm25, 55.5, 150.4, 151, 200);
  else if (pm25 <= 250.4) return map(pm25, 150.5, 250.4, 201, 300);
  else return map(pm25, 250.5, 500.4, 301, 500);
}

// ส่งข้อมูลไปยัง CynoIoT Platform
void sendToCynoIoT(float pm25, float pm10, float co2, int aqi, float temp, float hum) {
  if (WiFi.status() == WL_CONNECTED) {
    HTTPClient http;
    http.begin(cynoiotUrl);
    http.addHeader("Content-Type", "application/json");
    http.addHeader("Authorization", deviceToken);
    
    // สร้าง JSON payload
    String payload = "{";
    payload += "\"pm25\":" + String(pm25) + ",";
    payload += "\"pm10\":" + String(pm10) + ",";
    payload += "\"co2\":" + String(co2) + ",";
    payload += "\"aqi\":" + String(aqi) + ",";
    payload += "\"temperature\":" + String(temp) + ",";
    payload += "\"humidity\":" + String(hum);
    payload += "}";
    
    int httpResponseCode = http.POST(payload);
    
    if (httpResponseCode > 0) {
      Serial.println("Data sent to CynoIoT successfully");
    } else {
      Serial.println("Error sending data to CynoIoT");
    }
    
    http.end();
  }
}