===== Practical Example: Design of an Air Quality Monitoring System for a Conference Room =====

As part of the practical analysis, a simple measurement node dedicated to monitoring environmental parameters in a conference room was designed and tested.

=== Concept and Components ===

The system is based on an **Edge Computing** architecture—this means that the decision to activate supporting systems (e.g., ventilation) is made directly on the device. This shortens response time and increases the building's reliability in the event of a Wi-Fi network failure.

=== Tools Used: ===

  * **Simulator:** Wokwi (an environment for prototyping embedded systems). (( Wokwi Environment Documentation, ESP32 Simulator, https://docs.wokwi.com/guides/esp32, accessed: 18.01.2026. ))
  * **Microcontroller:** ESP32 (chosen for its low power consumption and integrated connectivity).
  * **Sensor:** DHT22 (a digital sensor measuring temperature and humidity with high precision).
  * **Signaler:** LED diode with a 220Ω resistor (simulating the activation of air conditioning/heat recovery).

**Wiring Diagram (Hardware)**
The following diagram shows the physical connection structure implemented on the virtual microcontroller:

{{ :wiki:schemat.png?nolink&600 |}}

**DHT22 Wiring:** 
  * VCC -> 3.3V
  * GND -> GND
  * Data -> GPIO 15
**LED Wiring:** 
  * Anode (+) -> Resistor -> GPIO 2
  * Cathode (-) -> GND

{{ galeria:schemat_polaczen.svg | ESP32 Wiring Diagram}}

=== Software Implementation ===

The following code performs parameter readings every 2 seconds. It includes a function to filter out erroneous readings (isnan) and threshold logic for comfort levels, set to a temperature range of 18°C to 24°C and humidity between 30% and 60%.

{{ galeria:kod.png?nolink&600 |}}

=== Results ===

Analysis of the prototype showed that the DHT22 sensor, despite its simplicity, is sufficient for monitoring general work comfort in a conference room. In a real-world IoT-managed building deployment, a Wi-Fi section would be added to the code to handle data transmission to a central database. This would allow the property manager to generate daily reports and optimize the building's heating curve.

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