ESP32 Smart Room

ESP32 Smart Room is a standalone IoT room monitoring panel built with a Freenove ESP32 Wrover, TFT touchscreen, BME280 environmental sensor, DS3231 RTC module, RGB status LED, buzzer alerts and a local WiFi web dashboard.

The device reads room conditions, displays live data on the TFT screen and exposes a browser-based dashboard directly from the ESP32 access point. It is designed as a compact embedded prototype that combines sensor communication, touch UI, local alerts, persistent settings and a self-hosted web interface.

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Table of Contents

Show contents

• Features
• Project Overview
• Demo / Photos
• Hardware
• How It Works
• User Interfaces
  • TFT Touchscreen
  • Web Dashboard
• Wiring
  • I2C Bus
  • TFT Display and Touch Controller
  • BME280
  • DS3231
  • RGB LED
  • Passive Buzzer
• Software
• TFT_eSPI Configuration
• Setup
• Implementation Highlights
• Limitations
• Possible Improvements
• Authors
• License

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Features

• Live temperature, humidity and pressure monitoring
• Real-time clock using a DS3231 RTC module
• Local TFT touchscreen interface with multiple screens
• Built-in ESP32 WiFi access point
• Web dashboard hosted directly on the ESP32
• Configurable temperature thresholds
• RGB LED status indicator for temperature ranges
• Passive buzzer alerts for temperature state changes
• Persistent settings stored in ESP32 non-volatile memory
• Min/max temperature tracking since startup
• I2C and SPI communication in one embedded project
• Reproducible TFT_eSPI configuration included in the repository

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Project Overview

Note

This project is a functional embedded prototype focused on local monitoring, direct interaction and standalone operation. It does not require an external server, cloud service or mobile application.

The ESP32 communicates with the BME280 sensor over I2C to read room temperature, humidity and pressure. The DS3231 RTC module provides current time independently from the internet. Data is shown locally on a TFT touchscreen and remotely through a web dashboard served by the ESP32.

The project also includes a simple local alert system. Temperature thresholds can be changed from the TFT interface or the web dashboard. Depending on the current temperature range, the RGB LED changes color and the buzzer can play a short sound alert.

The whole firmware is currently kept in a single Arduino sketch to make flashing and reviewing the prototype straightforward.

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Demo / Photos

Hardware photos, TFT screenshots, web dashboard preview and Fritzing wiring diagram are available below.

Final build

TFT screens

The TFT interface contains four screens.

MAIN

SET

STAT

INFO

Web dashboard

Wiring diagram

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Hardware

Important

All modules in this setup are powered from 3.3V. Do not connect the BME280, TFT logic or RTC data lines to 5V logic.

Component	Purpose
Freenove ESP32 Wrover	Main microcontroller
TFT display with XPT2046 touch controller	Local graphical user interface
BME280	Temperature, humidity and pressure sensor
DS3231	Real-time clock module
RGB LED, common anode	Temperature status indicator
Passive buzzer	Sound alerts
Resistors	Current limiting for LED and buzzer
Jumper wires / breadboard	Prototype wiring

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How It Works

The ESP32 reads environmental data from the BME280 sensor and time data from the DS3231 RTC module. The current room state is displayed on the TFT touchscreen and can also be checked from the web dashboard.

The RGB LED changes color depending on configurable temperature thresholds:

Temperature range	RGB color	Meaning
Below blue threshold	Blue	Cold
Between blue and green threshold	Green	Normal
Between green and yellow threshold	Yellow	Warm
Above yellow threshold	Red	Hot

When the temperature enters a different range, the RGB LED state is updated. If the buzzer is enabled, the device also plays a short alert sound.

Settings such as temperature thresholds and buzzer state are stored using ESP32 Preferences, so they are preserved after restart or power loss.

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User Interfaces

Tip

The project provides both a local TFT interface and a browser-based dashboard, so the device can be used without any external server.

TFT Touchscreen

The TFT interface contains four screens:

Screen	Description
MAIN	Temperature, humidity, pressure, current time and quick buzzer mute
SET	Temperature thresholds and buzzer settings
STAT	WiFi status, sensor status, current temperature state and min/max temperature
INFO	Project and author information

Touch input is handled through the XPT2046 touch controller.

Web Dashboard

The ESP32 creates its own WiFi access point and serves a local web dashboard.

Parameter	Value
SSID	SmartRoom-ESP32
Password	12345678
Dashboard URL	http://192.168.4.1

Warning

The ESP32 runs in access point mode, so the dashboard is available only after connecting directly to the device WiFi network.

The web dashboard allows you to:

• view live BME280 sensor readings,
• check the current RTC time,
• view module status,
• inspect current thresholds,
• change temperature thresholds,
• enable or disable the buzzer.

The dashboard separates live values from editable form fields, so automatic refresh does not interrupt changing settings.

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Wiring

I2C Bus

The BME280 and DS3231 modules share the same I2C bus.

Signal	ESP32 GPIO
SDA	GPIO21
SCL	GPIO22

Note

BME280 modules may use either 0x76 or 0x77, depending on the board variant.

Typical I2C addresses:

Module	Address
BME280	0x76 or 0x77
DS3231	0x68

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TFT Display and Touch Controller → Freenove ESP32 Wrover

TFT / Touch pin	ESP32 pin	Notes
VCC	3.3V	Power
GND	GND	Ground
LED	3.3V	Backlight
CS	GPIO5	TFT chip select
RESET	GPIO33	TFT reset
DC	GPIO32	TFT data/command
SDI / MOSI	GPIO23	SPI MOSI
SCK	GPIO18	SPI clock
SDO / MISO	GPIO19	SPI MISO
T_CLK	GPIO18	Shared with SCK
T_CS	GPIO14	Touch chip select
T_DIN	GPIO23	Shared with MOSI
T_DO	GPIO19	Shared with MISO
T_IRQ	GPIO34	Touch interrupt

TFT pins are configured in the TFT_eSPI library inside User_Setup.h.

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BME280 → Freenove ESP32 Wrover

BME280 pin	ESP32 pin	Notes
VIN / VCC	3.3V	Power
GND	GND	Ground
SDA	GPIO21	I2C SDA
SCL	GPIO22	I2C SCL
CSB	Not connected	I2C mode
SDO	Not connected	Default module address

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DS3231 → Freenove ESP32 Wrover

DS3231 pin	ESP32 pin	Notes
VCC	3.3V	Power
GND	GND	Ground
SDA	GPIO21	Shared I2C SDA
SCL	GPIO22	Shared I2C SCL

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RGB LED, Common Anode → Freenove ESP32 Wrover

RGB LED pin	ESP32 pin	Notes
Common anode	3.3V	Shared LED anode
R	GPIO27	Through resistor
G	GPIO26	Through resistor
B	GPIO25	Through resistor

The RGB LED is a common anode LED, so the project uses inverted control logic.

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Passive Buzzer → Freenove ESP32 Wrover

Buzzer pin	ESP32 pin	Notes
+	GPIO13	Through 220Ω resistor
-	GND	Ground

The passive buzzer is controlled with PWM, which allows it to play simple tones and short sound signals.

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Software

The project targets the Arduino ecosystem on ESP32 and uses the following libraries:

• SPI.h
• Wire.h
• WiFi.h
• WebServer.h
• Preferences.h
• TFT_eSPI.h
• XPT2046_Touchscreen.h
• Adafruit_BME280.h
• RTClib.h

Additional dependencies may be required for the BME280 sensor:

• Adafruit Unified Sensor
• Adafruit BusIO

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TFT_eSPI Configuration

The TFT display uses the TFT_eSPI library with a custom configuration prepared for:

ESP32 WROVER + ILI9341 SPI TFT + XPT2046 touch controller

This repository includes the exact configuration used in this project:

docs/tft/User_Setup.h

To use the same display setup, copy this file into your local TFT_eSPI library directory and replace the default User_Setup.h.

Warning

Back up your existing TFT_eSPI/User_Setup.h before replacing it, especially if you use the same Arduino installation for other TFT projects.

Display driver

The project uses the ILI9341 driver variant:

#define ILI9341_2_DRIVER
#define TFT_WIDTH  240
#define TFT_HEIGHT 320

The screen is used in landscape mode by the application code:

#define DISPLAY_ROTATION 1

Color configuration

The display uses BGR color order and inverted colors:

#define TFT_RGB_ORDER TFT_BGR
#define TFT_INVERSION_ON

TFT SPI pins

#define TFT_MISO 19
#define TFT_MOSI 23
#define TFT_SCLK 18

#define TFT_CS   5
#define TFT_DC   32
#define TFT_RST  33

Touch controller

The XPT2046 touch controller uses a separate chip select pin:

#define TOUCH_CS 14

The touch interrupt pin is defined in the project code:

#define TOUCH_IRQ 34

Loaded fonts

The configuration enables the standard TFT_eSPI fonts and smooth fonts:

#define LOAD_GLCD
#define LOAD_FONT2
#define LOAD_FONT4
#define LOAD_FONT6
#define LOAD_FONT7
#define LOAD_FONT8
#define LOAD_GFXFF
#define SMOOTH_FONT

SPI frequencies

#define SPI_FREQUENCY       10000000
#define SPI_READ_FREQUENCY  10000000
#define SPI_TOUCH_FREQUENCY 2500000

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Setup

1. Clone the repository

git clone https://github.com/PoProstuWitold/esp32-smart-room.git
cd esp32-smart-room

2. Install required libraries

Install the required Arduino libraries manually in the Arduino IDE.

Tip

If the BME280 library does not compile, also install Adafruit Unified Sensor and Adafruit BusIO.

3. Configure TFT_eSPI

Copy the provided TFT configuration file:

docs/tft/User_Setup.h

into your local TFT_eSPI library directory and replace the default User_Setup.h.

On Linux with Arduino IDE, the path is usually:

~/Arduino/libraries/TFT_eSPI/User_Setup.h

This project uses an ILI9341_2_DRIVER setup with BGR color order, color inversion enabled, SPI at 10 MHz and touch SPI at 2.5 MHz.

4. Upload the code

Connect the Freenove ESP32 Wrover board and upload the project.

5. Connect to the ESP32 WiFi

After startup, connect to:

SSID: SmartRoom-ESP32
Password: 12345678

Then open:

http://192.168.4.1

Caution

The default access point password is intended only for a local prototype/demo setup. Change it before using the project outside a controlled environment.

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Implementation Highlights

Non-blocking buzzer playback

The buzzer logic uses millis() instead of long blocking delay() calls. This keeps the system responsive while sounds are playing.

During buzzer playback, the ESP32 can still:

• handle web server requests,
• process touch input,
• update the TFT screen,
• read sensor data,
• update RTC time.

Shared settings between interfaces

Temperature thresholds and buzzer state are shared between the TFT interface and the web dashboard. Changing settings in one interface immediately affects the whole device.

Persistent configuration

The project uses ESP32 Preferences to store:

• blue temperature threshold,
• green temperature threshold,
• yellow temperature threshold,
• buzzer enabled/disabled state.

This makes the configuration survive resets and power loss.

Standalone operation

The ESP32 serves its own dashboard and creates its own WiFi access point. This makes the prototype independent from external servers, routers or cloud platforms.

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Limitations

This project is a working prototype, not a production-ready smart home device.

Known limitations:

• the dashboard works in ESP32 access point mode only,
• there is no user authentication,
• there is no TLS/HTTPS support,
• sensor history is not stored long-term,
• the current build does not include OTA updates,
• the firmware is kept in one Arduino sketch,
• the hardware is still a breadboard/prototype setup.

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Possible Improvements

Possible next steps for this project:

• split the firmware into smaller modules,
• add PlatformIO configuration for reproducible builds,
• add long-term sensor history and charts,
• add WiFi station mode in addition to access point mode,
• add simple dashboard authentication,
• add OTA firmware updates,
• design a PCB or enclosure,
• integrate the device with Home Assistant or MQTT.

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Authors

• Witold Zawada (GitHub)
• Wiktor Wypyszyński (GitHub)

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License

This project is released under the MIT License.

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