Advanced Control

This example demonstrates a complete IoT system with multiple virtual pins, LED control, and sensor simulation using Firebase real-time synchronization. Perfect for learning the virtual pin architecture and testing your setup.

Hardware Required

ESP8266 or ESP32 development board
LED (any color)
RGB LED or PWM-controlled LED
220Ω resistor for LED
Breadboard and jumper wires

Wiring

ESP8266/ESP32    Components
GPIO 12 (D6) →   LED (+) → 220Ω → GND
GPIO 13 (D7) →   RGB LED (PWM control)
3.3V         →   LED VCC
GND          →   LED GND

Code

#include <Arduino.h>
#include <DecentIoT.h>

// Firebase credentials
#define FIREBASE_URL "your-firebase-url"
#define FIREBASE_AUTH "your-web-api-key"
#define AUTH_EMAIL "your-auth-email"
#define AUTH_PASS "your-auth-password"
#define PROJECT_ID "your-project-id"
#define USER_ID "your-user-id"
#define DEVICE_ID "your-device-id"

#define WIFI_SSID "your-wifi-ssid"
#define WIFI_PASS "your-wifi-password"
const int ledPin = D6; // D6 = GPIO12 on ESP8266
const int rgbPin = D7; // D7 = GPIO13 on ESP8266

// LED state handler
DECENTIOT_RECEIVE(P0) {
  digitalWrite(ledPin, value);
  Serial.printf("[P0] LED state = %s\n", value ? "ON" : "OFF");
}

DECENTIOT_SEND(P1, 60*1000) {
  // Generate random temperature value between 0-100
  int temperature = random(0, 101); // random(min, max) generates numbers from min to max-1
  DecentIoT.write(P1, temperature); // Send temperature to Firebase
  Serial.printf("[P1] Temperature = %d\n", temperature );
}

DECENTIOT_SEND(P2, 60*1000) {
  // Generate random humidity value between 0-100
  int humidity = random(0, 101); // random(min, max) generates numbers from min to max-1
  DecentIoT.write(P2, humidity); // Send humidity to Firebase
  Serial.printf("[P2] Humidity = %d\n", humidity );
}

DECENTIOT_RECEIVE(P3) {
  int sliderValue = value;
  int pwmValue = sliderValue * 255 / 100;
  analogWrite(rgbPin, pwmValue);
  Serial.printf("[P3] RGB Brightness = %d (slider: %d)\n", pwmValue, sliderValue);
}

void setup() {
  Serial.begin(115200);
  Serial.println("\n--- Initializing DecentIoT Device ---");

  // Initialize LED pin
  pinMode(ledPin, OUTPUT);
  pinMode(rgbPin, OUTPUT);
  pinMode(LED_BUILTIN, OUTPUT);
  digitalWrite(ledPin, LOW); // Ensure LED is off initially
  digitalWrite(LED_BUILTIN, LOW);

  // User handles WiFi connection
  WiFi.begin(WIFI_SSID, WIFI_PASS);
  while (WiFi.status() != WL_CONNECTED) {
    delay(500);
    Serial.print(".");
    digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
  }
  Serial.println("WiFi connected!");
  digitalWrite(LED_BUILTIN, HIGH);

  // Now start DecentIoT (cloud connection)
  DecentIoT.begin(FIREBASE_URL, FIREBASE_AUTH, PROJECT_ID, USER_ID, DEVICE_ID, AUTH_EMAIL, AUTH_PASS);
}

void loop() {
  // User checks WiFi and reconnects if needed
  if (WiFi.status() != WL_CONNECTED) {
    digitalWrite(LED_BUILTIN, LOW);
    Serial.println("[WiFi] Disconnected! Reconnecting...");
    WiFi.disconnect();
    WiFi.begin(WIFI_SSID, WIFI_PASS);
    // Optionally: wait for connection, show status, etc.
    int attempts = 0;
    while (WiFi.status() != WL_CONNECTED && attempts < 20) {
      delay(500);
      Serial.print(".");
      digitalWrite(LED_BUILTIN, !digitalRead(LED_BUILTIN));
      attempts++;
    }
    if (WiFi.status() == WL_CONNECTED) {
      Serial.println("WiFi reconnected! Restarting device...");
      delay(1000);
      ESP.restart();
    }
  }

  DecentIoT.run();
  delay(10);
}

// Virtual Pin Mappings:
// P0 - LED Control (bool)
// P1 - Temperature (int) - Random values for demo
// P2 - Humidity (int) - Random values for demo  
// P3 - RGB Brightness Control (int) - PWM slider

Dashboard Setup

Create Project in DecentIoT web dashboard
Add Widgets:
- Switch named led_control (maps to P0)
- Gauge named temperature (maps to P1, range 0-100)
- Gauge named humidity (maps to P2, range 0-100)
- Slider named rgb_brightness (maps to P3, range 0-100)
Configure Layout:
- Group controls together
- Group sensors together
Save and test all functions

How It Works

Virtual Pin Architecture

Pin	Function	Type	Description
P0	LED Control	bool	Manual LED on/off control
P1	Temperature	int	Simulated temperature (0-100)
P2	Humidity	int	Simulated humidity (0-100)
P3	RGB Brightness	int	PWM brightness control (0-100)

System Features

LED Control: P0 provides simple on/off control
Sensor Simulation: P1 and P2 send random values every 60 seconds
PWM Control: P3 provides brightness control with slider
WiFi Reconnection: Automatic WiFi reconnection with device restart
Real-time Sync: Firebase automatically syncs all data
Automatic Processing: Library handles all communication seamlessly

Firebase Real-time Synchronization

// Data is automatically synced to dashboard
DecentIoT.write("P1", temperature);
// Dashboard updates immediately

// Library automatically handles all communication

Advanced Features

Conditional Control

// Only send data when system is enabled
DECENTIOT_SEND(P1, 10000) {
  if (systemEnabled) {
    float temperature = dht.readTemperature();
    if (!isnan(temperature)) {
      DecentIoT.write("P1", temperature);
    }
  }
  
  // Library automatically handles communication
}

Error Handling

// Enhanced error handling
DECENTIOT_SEND(P1, 10000) {
  if (systemEnabled) {
    float temperature = dht.readTemperature();
    if (!isnan(temperature)) {
      DecentIoT.write("P1", temperature);
      Serial.printf("[P1] Temperature: %.1f°C\n", temperature);
    } else {
      DecentIoT.write("P1", -999); // Error value
      Serial.println("[P1] Sensor error - check connections");
    }
  }
  
  // Library automatically handles communication
}

Firebase vs MQTT Comparison

Feature	Firebase Library	MQTT Library
Real-time Sync	Automatic	Manual
Connection	Firebase Realtime DB	MQTT Broker
Authentication	Firebase Auth	MQTT Credentials
Processing	Automatic	Automatic
Setup	Firebase project required	MQTT broker required
Cost	Firebase free tier	Broker hosting costs
Offline Support	Built-in	Limited

Troubleshooting

System not responding:

Check system status switch (P0) in dashboard
Verify all wiring connections
Check Serial Monitor for error messages

Sensors not reading:

Verify sensor connections
Check power supply (3.3V)
Ensure pull-up resistors are connected

Controls not working:

Check system is enabled (P0)
Verify output pin assignments
Check relay module connections

Instructions not received:

Ensure DecentIoT.run() is called regularly in your main loop
Check Firebase authentication
Verify database rules allow read/write access

Required Libraries

Install these libraries via Arduino Library Manager:

DHT sensor library by Adafruit
Adafruit Unified Sensor (dependency)

Next Steps

MQTT Examples - Alternative to Firebase
Scheduling Guide - Advanced scheduling features
API Reference - Complete method documentation

Advanced Control

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