ESP8266/ESP32    DHT22
GPIO 4 (D2)  →   Data Pin
3.3V         →   VCC
GND          →   GND
GPIO 4 (D2)  →   10kΩ Resistor → 3.3V (pull-up)

/*
  DecentIoT MQTT Library - Simple DHT Sensor Example
  
  Hardware:
  - DHT22 sensor on pin D4
  - LED on pin D6
  
  Virtual Pins:
  - P0: LED Control (receive)
  - P1: Temperature (send)
  - P2: Humidity (send)
*/

#include <DecentIoT.h>
#include <ESP8266WiFi.h>
#include <DHT.h>

// Configuration
#define MQTT_BROKER "your-mqtt-cluster-url"
#define MQTT_PORT 8883
#define MQTT_USERNAME "broker-access-username"
#define MQTT_PASSWORD "broker-access-pass"
#define PROJECT_ID "your-project-id"
#define USER_ID "your-user-id"
#define DEVICE_ID "your-device-id"
#define WIFI_SSID "your-wifi-name"
#define WIFI_PASS "wifi-password"

// Hardware pins
#define LED_PIN D6
#define DHT_PIN D4

// Create DHT sensor
DHT dht(DHT_PIN, DHT22);

// LED control from dashboard
DECENTIOT_RECEIVE(P0) {
    digitalWrite(LED_PIN, value);
    Serial.printf("[P0]LED: %s\n", value ? "ON" : "OFF");
}

// Send temperature every 10 seconds
DECENTIOT_SEND(P1, 10000) {
    float temp = dht.readTemperature();
    DecentIoT.write(P1, temp);
    Serial.printf("[P1] Temperature: %.1f°C\n", temp);
}

// Send humidity every 10 seconds
DECENTIOT_SEND(P2, 10000) {
    float humidity = dht.readHumidity();
    DecentIoT.write(P2, humidity);
    Serial.printf("[P2] Humidity: %.1f%%\n", humidity);
}

void setup() {
    Serial.begin(115200);
    
    // Initialize pins
    pinMode(LED_PIN, OUTPUT);
    pinMode(LED_BUILTIN, OUTPUT);
    digitalWrite(LED_PIN, LOW);
    
    // Initialize DHT sensor
    dht.begin();
    
    // Connect to WiFi
    WiFi.begin(WIFI_SSID, WIFI_PASS);
    while (WiFi.status() != WL_CONNECTED) {
        delay(500);
        Serial.print(".");
    }
    Serial.println("[WiFi] connected!");
    
    // Initialize DecentIoT
    DecentIoT.begin(MQTT_BROKER, MQTT_PORT, MQTT_USERNAME, MQTT_PASSWORD, PROJECT_ID, USER_ID, DEVICE_ID);
}

void loop() {
    DecentIoT.run();
    delay(10);
}

// Enhanced sensor reading with error handling
DECENTIOT_SEND(P1, 10000) {
  float temperature = dht.readTemperature();
  if (!isnan(temperature)) {
    DecentIoT.write(P1, temperature);
    Serial.printf("[P1] Temperature: %.1f°C\n", temperature);
  } else {
    // Send error status
    DecentIoT.write(P1, -999);
    Serial.println("[P1] Sensor error - check connections");
  }
}

// Add more sensors to different virtual pins
DECENTIOT_SEND(P3, 5000) {
  int lightLevel = analogRead(A0);
  DecentIoT.write(P3, lightLevel);
  Serial.printf("[P3] Light Level: %d\n", lightLevel);
}

DECENTIOT_SEND(P4, 15000) {
  float pressure = readPressure(); // Your pressure sensor function
  DecentIoT.write(P4, pressure);
  Serial.printf("[P4] Pressure: %.2f hPa\n", pressure);
}

// Different reading intervals for different sensors
DECENTIOT_SEND(P1, 5000) {   // Temperature every 5 seconds
  float temp = dht.readTemperature();
  DecentIoT.write(P1, temp);
}

DECENTIOT_SEND(P2, 30000) {  // Humidity every 30 seconds
  float humidity = dht.readHumidity();
  DecentIoT.write(P2, humidity);
}