SmartHomeShop Docs

Installation Guide

Have UltimateSensor Mini v1? Use the Mini v1 Installation Guide. Mini v1 uses different hardware and does not use the Mini v2 Ethernet/PoE firmware flow.

This guide is for UltimateSensor Mini v2 hardware with ESP32-C6. Mini v2 supports WiFi, Bluetooth provisioning, Ethernet firmware, PoE power and, with the Thread firmware, Thread.

Unboxing

Unbox the UltimateSensor Mini v2 package. The box contains:

  • UltimateSensor Mini v2 in white or black, with LD2412 + LD2450 already installed
  • SPS30 particulate matter sensor, pre-installed, if you ordered the version with SPS30
  • A QR code on the inside of the box, which leads to this manual

A USB-C cable, power adapter and mount are not in the box. The USB-C adapter set (5 V adapter with a 3 m USB-C cable) and the Stand & Wall Mount are sold separately.

Optional LD2460 Upgrade

UltimateSensor Mini v2 ships with LD2412 + LD2450 installed by default. Only replace the LD2450 if you have the optional LD2460 upgrade module and plan to flash the matching LD2460 firmware variant.

Disconnect power before opening the housing. Work slowly and avoid pulling on cables or sensor boards.

To replace LD2450 with LD2460:

  1. Place the Mini v2 on a clean surface with the bottom side facing you.
  2. Find the small notch at the bottom of the housing.
  3. Use a small flat screwdriver to carefully click open the front of the housing.
  4. Remove the transparent plastic light guide in front of the LEDs.
  5. Carefully unclip the upper front cover plate.
  6. Remove the LD2450 module and replace it with the LD2460 module.
  7. Put the upper front cover plate back in place.
  8. Reinstall the transparent LED light guide.
  9. Carefully click the housing closed again in reverse order.
  10. Flash the matching LD2460 firmware.

After the upgrade, LD2460 replaces LD2450. Use the LD2460 target 1-5 X/Y/Distance/Angle entities and the shared Room Designer polygon zones instead of the LD2450-specific zone entities.

Before mounting and configuring Room Designer, follow the complete Mini v2 LD2460 Upgrade Guide. It explains the required antenna orientation check, wall height, angle and detection range.

Optional: Add the SPS30 Later

If your Mini v2 came without SPS30, you can add the SPS30 module yourself.

Disconnect power before opening the housing. Work slowly and avoid pulling on cables or sensor boards.

  1. Place the Mini v2 on a clean surface with the bottom side facing you.
  2. Find the small notch at the bottom of the housing.
  3. Use a small flat screwdriver to carefully click the housing open.
  4. Take the circuit board out of the housing.
  5. Click the SPS30 into the back of the housing.
  6. Connect the SPS30 to the circuit board with the adapter cable from the SPS30 box.
  7. Put the circuit board back and carefully click the housing closed.
  8. Switch to the matching Complete firmware. The firmware page explains how.

Step 1: Choose WiFi or Ethernet

Your Mini v2 normally ships with WiFi firmware installed. Most users can install it through WiFi and never need to switch firmware.

Connection Best for Power
WiFi Standard setup and easy onboarding USB-C
Ethernet Most stable network connection USB-C or PoE
PoE One cable for power and network 802.3af PoE switch or injector

Step 2A: WiFi Setup

When the Mini v2 starts for the first time, or after flashing WiFi firmware, it creates a fallback WiFi hotspot:

  1. Look for the hotspot:
    • SSID: ultimatesensor-mini (older firmware: ultimatesensor-mini-v2)
    • Password: the same as the SSID
  2. Connect your phone or laptop to this network.
  3. A captive portal should open automatically.
  4. Select your own 2.4 GHz WiFi network and enter the password.
  5. The Mini v2 restarts and connects to your network.

If the captive portal does not open, go to http://192.168.4.1/ manually in your browser.

Step 2B: Ethernet or PoE Setup

Ethernet firmware is only for UltimateSensor Mini v2.

Before switching to Ethernet, check:

  • DHCP is enabled on your network.
  • The Mini v2 is on the same network or VLAN as Home Assistant.
  • Your firewall allows traffic between Home Assistant and the Mini v2.
  • If you use PoE, your switch or injector supports 802.3af PoE.

Option 1: Flash Ethernet Firmware with the Web Flasher

This is the recommended method when you want Ethernet from the start. The web flasher returns the device to its factory settings.

  1. Connect the Mini v2 to your computer with USB-C.
  2. Open the web flasher: smarthomeshop.io/en/firmware?product=ultimatesensor-mini.
  3. Select an UltimateSensor Mini v2 Ethernet firmware variant:
    • Ethernet Basic if your Mini v2 is without SPS30.
    • Ethernet Complete if your Mini v2 is with SPS30.
  4. Click Install firmware and choose the USB port of your device.
  5. Connect Ethernet or PoE before adding the device to Home Assistant.

Option 2: Switch from WiFi to Ethernet in Home Assistant

Use this only when the device is already online through WiFi.

  1. Connect the Ethernet cable or PoE cable first.
  2. Open the Mini v2 device in Home Assistant.
  3. Find UltimateSensor Mini V2 Firmware Variant and choose the Ethernet variant that matches your device, for example Ethernet Basic (local).
  4. Enable the UltimateSensor Mini V2 Firmware update entity if it is still disabled.
  5. Install the update through that entity and wait for the device to reboot.

Important: WiFi stops working after the Ethernet firmware is installed. Always connect Ethernet before switching.

Switching Back from Ethernet to WiFi

You cannot reliably switch from Ethernet back to WiFi through Home Assistant, because the device may disconnect before the new WiFi firmware finishes installing.

To switch back:

  1. Connect the Mini v2 to your computer with USB-C.
  2. Open the web flasher: smarthomeshop.io/en/firmware?product=ultimatesensor-mini.
  3. Select the correct Mini v2 WiFi variant:
    • WiFi Basic if your Mini v2 is without SPS30.
    • WiFi Complete if your Mini v2 is with SPS30.
  4. Flash the device.
  5. Configure WiFi again through the fallback hotspot. Its password is the same as its name.

Step 3: Add to Home Assistant

  1. Open Home Assistant.
  2. Go to Settings -> Devices & services.
  3. Look for the ESPHome discovery notification.
  4. Add the UltimateSensor Mini v2 device.

If it is not discovered automatically, find the device IP address in your router and add it manually through the ESPHome integration.

Step 4: Let Sensors Stabilize

After first boot:

  • Wait at least 10 minutes for initial sensor readings.
  • CO2 readings can need up to 24 hours to stabilize.
  • Use the calibration guide if readings need adjustment.

Placement

Place the Mini v2:

  • Around 1 to 2 meters high
  • Aimed at the area you want to monitor
  • Away from direct sunlight, radiators and ventilation outlets
  • With enough airflow around the housing

Stand & Wall Mount

The Stand & Wall Mount is sold separately. The set has a slide piece, a wall bracket and a freestanding foot.

  1. Slide the slide piece onto the Mini v2.
  2. For a wall, fix the wall bracket to the wall first. For a desk, shelf or cabinet, use the freestanding foot.
  3. Click the slide piece into the wall bracket or the foot.

No Voice Assistant on Mini v2

UltimateSensor Mini v2 does not include microphone, speaker, media player or local wake word support. If you need voice assistant in a current product, use the regular UltimateSensor v2.