Designing an “ambient computing” room node for Home Assistant (ESP32-P4 + PoE)
I'm currently planning my future house infrastructure and started prototyping a modular room node system for Home Assistant before the actual construction begins.
Current infrastructure:
- Home Assistant running in Docker on UmbrelOS
- HP ThinClient as server
- Aruba PoE switch for centralized power/network
- Ethernet/PoE planned in multiple rooms
The idea is to have one PoE-powered "room client" per room instead of separate devices for:
- thermostat
- presence sensor
- smart speaker
- intercom
- doorbell chime
Current prototype hardware:
- ESP32-P4-POE-ETH
- LD2420 mmWave presence sensor
- AHT20 temperature/humidity sensor
- MAX98357A audio amp
- small speaker
- OLED display (only for debugging/setup during development)
Main priority right now is audio/TTS: I mainly want room speakers for things like:
- "someone is at the door"
- notifications
- alarms
- washing machine finished
- Home Assistant announcements
Planned functionality:
- room temperature + humidity monitoring using the AHT20
- occupancy detection using the LD2420
- floor heating control based on room temperature/humidity
- dew point monitoring during summer cooling to prevent condensation
- doorbell and presence-based automations
Future ideas:
- local TTS/STT
- intercom functionality
- push-to-talk button
- optional door opener button
- local AI/LLM integration through a centralized host/server (not running directly on the room clients)
One important requirement: I want the architecture to support a future upgrade to proper ceiling speakers (probably AirPlay 2 / multiroom audio for the kids' rooms later on).
The second big topic is the industrial design of the whole thing.
I would love something minimalistic and "ambient computing"-like instead of a typical tablet-on-the-wall smart home aesthetic.
Current inspiration is something between:
- HAL9000
- sci-fi intercoms
- hidden technology
- Scandinavian minimalism
No cameras planned in private rooms.
Has anyone here built something similar? Especially interested in:
- audio/microphone experiences
- ESPHome limitations
- PoE/audio noise issues
- microphone placement
- hidden speaker designs
- long-term maintainability
- industrial design ideas