UltimateSensor for Home Assistant / ESPHome

UltimateSensor is an ESPHome-based room sensor for Home Assistant. It measures air quality, occupancy, light, temperature, humidity, VOC/NOx index values, and optionally particulate matter, with local operation over WiFi or Ethernet/PoE.

Product page: https://ultimatesensor.nl/en

How It Works

UltimateSensor combines multiple room sensors on one ESP32 device. The ESPHome firmware exposes all measurements directly to Home Assistant and supports WiFi or wired Ethernet depending on the firmware variant.

The Basic firmware uses the shared configuration without the SPS30 particulate matter sensor. The Complete firmware adds SPS30 particulate matter measurements and Home Assistant controls for the PM sensor and night mode.

Key Features

• CO2 sensing with SCD41
• Temperature and humidity sensing
• Light sensing with BH1750
• VOC and NOx index sensing with SGP4x
• LD2450 mmWave occupancy and target tracking
• OLED display with Home Assistant LCD display control
• RGB back light and ESP status LED
• WiFi firmware with captive portal fallback
• Ethernet firmware for wired connectivity and PoE installations
• Optional SPS30 particulate matter sensing in the Complete variant
• SPS30 idle-cycle controls aligned with UltimateSensor Mini to reduce fan/laser runtime
• PM sensor and Night Mode controls in the Complete variant
• Fully local operation with ESPHome and Home Assistant

Hardware Versions

Version	Chip	Connectivity	Description
V1	ESP32	WiFi, Ethernet, and PoE	UltimateSensor hardware with Basic and Complete firmware variants

Variants

We publish customer-facing WiFi and Ethernet firmware variants for the V1 hardware.

Hardware	Variant	Description
V1 (ESP32)	WiFi Basic	WiFi firmware without the SPS30 particulate matter sensor
V1 (ESP32)	WiFi Complete	WiFi firmware with SPS30 particulate matter sensing
V1 (ESP32)	Ethernet Basic	Ethernet firmware without the SPS30 particulate matter sensor
V1 (ESP32)	Ethernet Complete	Ethernet firmware with SPS30 particulate matter sensing

Sensors

Sensor	Description
CO2	Room CO2 concentration
Temperature	Environment temperature
Humidity	Environment humidity
Light	Ambient light level
VOC Index	Volatile organic compound index
NOx Index	Nitrogen oxide index
Occupancy	mmWave occupancy detection
Target Position	LD2450 target X/Y position, speed, angle, distance, and resolution
PM1.0 / PM2.5 / PM4.0 / PM10	Particulate matter measurements in the Complete variant
WiFi Signal	WiFi signal strength in WiFi variants
Uptime	Device uptime

Getting Started

1. Power the UltimateSensor with USB-C or PoE where supported.
2. Flash the desired firmware with the web flasher or ESPHome CLI.
3. If WiFi is not configured yet, connect to the fallback hotspot.
4. Add the device to Home Assistant through the ESPHome integration.
5. Use the LCD display, PM sensor, and Night Mode controls from Home Assistant where available.

Web flasher: https://smarthomeshop.io/en/firmware Product page: https://ultimatesensor.nl/en

Version History

• Customer-facing release notes: CHANGELOG.md
• GitHub Releases: https://github.com/smarthomeshop/ultimatesensor/releases

Repository Layout

ultimatesensor/
├── ultimatesensor-v1/                  # V1 ESPHome configurations
│   ├── base.yaml                       # Shared device, sensors, display, and controls
│   ├── wifi.yaml                       # Shared WiFi connectivity package
│   ├── ethernet.yaml                   # Shared Ethernet connectivity package
│   ├── complete.yaml                   # SPS30 particulate matter package
│   ├── ultimatesensor-wifi-basic.yaml
│   ├── ultimatesensor-wifi-complete.yaml
│   ├── ultimatesensor-ethernet-basic.yaml
│   └── ultimatesensor-ethernet-complete.yaml
├── .github/workflows/                  # Build and release automation
├── CHANGELOG.md                        # Customer-facing firmware notes
└── images/

Firmware Downloads

Pre-built firmware manifests are published on the gh-pages branch.

• WiFi Basic: ultimatesensor-wifi-basic-manifest.json
• WiFi Complete: ultimatesensor-wifi-complete-manifest.json
• Ethernet Basic: ultimatesensor-ethernet-basic-manifest.json
• Ethernet Complete: ultimatesensor-ethernet-complete-manifest.json

Contributing

PRs and issues are welcome. Please keep changes modular and follow ESPHome best practices.

If a PR changes firmware behavior or release-visible functionality, add a customer-facing note to CHANGELOG.md under Unreleased.

Support

• Product info and guides: https://ultimatesensor.nl/en
• Store: https://smarthomeshop.io
• Community and support: https://smarthomeshop.io/discord

License

This project is released under the CC BY-NC 4.0 license. See license.