Guides
Build Guides
Practical build notes covering device wiring, power, communication, firmware updates, and field-oriented operation.
[IoT DIY Part 1] Vertical Market Ticker with ESP8266 and 16 Dot-Matrix Modules
A vertical MAX7219 ticker with 16 modules, zone splitting, Big Font UI, asynchronous rendering, and power troubleshooting.
[IoT DIY Part 2] Separating the Microcontroller and API Server
API key security, a Python broker server, Skip-on-Empty rotation, ESP non-blocking HTTP polling, and network freeze troubleshooting.
[IoT DIY Part 3] Multi-Sensor Fusion for Reducing Night-Time Visual Fatigue
CDS sensing, Doppler radar, debounce filtering, FSM logic, and DHT22 heat compensation for night-time ticker operation.
[IoT DIY Part 4] Interactive NeoPixel Mood Lamp with Sensor Fusion
NeoPixel 80 LEDs, acrylic light diffusion, power design, Doppler/sound/light sensors, and a FastLED state machine.
[IoT DIY Part 5] Captive Portal, Web Settings UI, and OTA Updates
How a personal ESP32 ticker became a configurable and remotely maintainable IoT device for other users.
[Part 25] AI Butler Method C: Raspberry Pi Integrated Home IoT Hub
Run the broker, dashboard, alerts, and storage together on a Raspberry Pi as one integrated home IoT server.
[Part 24] AI Butler Method B: Safe AI Broker with an Old PC and Telegram
Move API keys and AI decisions to a Python broker on an old PC, then send Telegram alerts safely.
[Part 23] AI Butler Method A: ESP32 Talking Directly to an LLM
Let the ESP32 talk directly to an LLM API and understand simple home events as Physical AI.
[Part 22] ESP32 Touch TFT Upgrade with Bluetooth
Move the hub brain to ESP32 and add a touch TFT display with Bluetooth headroom.
[Expansion] Color TFT Display Upgrade with 2.4-inch ILI9341
Upgrade the hub display from a small OLED to a larger color ILI9341 TFT screen.
[Part 20] The house finally fits on one screen
Bring the 20-slot sensor flow into one integrated screen and close the first Home IoT HUB series.
[Part 19] Cool the room only when someone is there
Combine presence and temperature conditions into air-conditioner automation while reducing alert fatigue.
[Part 18] See whether the dog bowl is empty
Measure remaining food with an HX711 load cell and filter weight spikes while the dog is eating.
[Part 17] Control the air conditioner from the IoT hub
Send IR commands to the air conditioner and manage reflection angle, feedback, and state mismatch.
[Part 16] Check lights and door lock together
Combine living-room light and door-lock state while handling light-sensor misreads and optocoupler isolation.
[Part 15] Do not leave the window open in the rain
Reduce rain-board corrosion by powering the rain sensor only during short measurement windows.
[Part 14] See leaks and water usage as numbers
Use a YF-S201 flow sensor to calculate water use while filtering pulse noise and preventing plumbing leaks.
[Part 13] The power bill is high, so make it visible
Track current with ACS712 and handle zero-offset calibration and electromagnetic noise.
[Part 12] Is the stuffy feeling actually air quality?
Measure CO2 and PM2.5 with MH-Z19B and PMS5003 while managing peak current, fan life, and sampling intervals.
[Part 11] Catch flame signs when nobody is home
Use a flame sensor while handling infrared sunlight false positives and safe alert rules.
[Part 10] Get warned before gas smell becomes obvious
Build an MQ-5 gas warning node while accounting for burn-in, alcohol-vapor false alarms, and placement.
[Part 9] Did I leave the gas stove on?
Use a K-type thermocouple and MAX6675 to judge burner temperature as a safety signal.
[Part 8] Verify boiler operation from pipe temperature
Read boiler and hot-water pipe temperature with DS18B20 sensors to confirm actual heating behavior.
[Part 7] Catch bathroom humidity before mold starts
Track bathroom humidity, decide ventilation timing, and handle condensation that can lock DHT22 readings.
[Part 6] Can I open the window now?
Place an outdoor temperature node near a balcony or window and deal with sunlight, rain, and winter power issues.
[Part 5] Check whether the refrigerator is really holding temperature
Use a waterproof DS18B20 to monitor refrigerator temperature without damaging the door seal.
[Part 4] When you keep wondering whether the door is closed
Use an MC-38 reed switch to detect the front-door state while checking magnetic interference from a steel door.
[Part 3] Stop guessing room climate and read the numbers
Build the basic DHT22 node that sends living-room temperature and humidity to hub slots 1 and 2.
[Part 2] Building the brain
Connect the ESP8266, OLED, and buzzer to build the central brain and display flow from the Part 1 architecture.
[Part 1] Why I started the Home IoT HUB
The starting point for an ESP8266 central hub and 20-slot structure that brings home state into one screen.
IoT remote update OTA test
Create firmware.bin, upload server files, and test OTA firmware updates.
Send ESP8266 DHT22 Readings to a Web Server
A remote equipment-room example using Wi-Fi upload, PHP receiving, and battery deep sleep.
ESP8266 + DHT22 Room Climate Logger
Sensor wiring, pull-up resistor, pin choice, and serial-log checks for a first build.
ESPHome Setup and First ESP32 Sensor Device
Create an ESP32 sensor node with YAML, logs, API, MQTT, and OTA checks.
Add ESP32/ESP8266 Boards to Arduino IDE
Download the IDE, add board manager URLs, install ESP packages and libraries, then verify compilation.
IoT Power and Noise Checklist
Reduce random reboots, sensor spikes, and relay noise before field deployment.
MQTT Sensor Node Flow
Organize telemetry, device state, control commands, and configuration topics.
Prepare Development Software
Install the tools needed for firmware upload, logs, MQTT testing, and automation.