Individually addressable LED strips — hundreds of tiny LEDs, each capable of its own color and brightness — controlled by ESP8266 and ESP32 microcontrollers running WLED firmware, integrated into Apple HomeKit and Home Assistant. The office lighting responds to time of day, calendar events, and sensor data. It sounds like overkill for an office, and it is. But it’s also a complete, working IoT system built from commodity hardware and open-source software — the same architecture pattern that shows up in commercial smart-building projects, just at a scale where I can solder the connections myself.
The Stack
The foundation is WS2812b LED strips: individually addressable, powered at 5V, and capable of 16 million colors per pixel. Each strip segment connects to an ESP8266 or ESP32 microcontroller flashed with WLED — open-source firmware that handles animation, color temperature, brightness scheduling, and network communication without writing custom code.
WLED exposes a local API that Home Assistant can talk to directly. HomeKit integration runs through Home Assistant’s HomeKit bridge, so Siri and the Home app work without needing any Apple-specific hardware in the loop.
What “Responds to Context” Actually Means
The lighting adapts to three signal types:
Time of day. Color temperature shifts from cooler white in the morning toward warmer amber in the afternoon, then dims into a low red-orange by evening. WLED handles this natively with its scheduling features.
Sensor data. Motion sensors, lux sensors, and temperature and power monitoring readings feed into automations.
What It Taught
Building this before doing any of the other LED projects set a baseline for what “done” looks like: stable firmware, clean wiring, reliable integration with the broader home automation system, and behavior that’s invisible until you notice it working exactly as intended.
The failure modes at this stage were mostly wiring and power: voltage drop over long runs, power supply noise showing up as color flicker. Fixing them at the office scale — where mistakes are low-stakes — made every subsequent project faster.
Part of the LED Lighting Projects collection.