SmartHomeShop Docs

Troubleshooting

Rapidly flashing red status LED on a VLAN without internet

If your UltimateSensor Mini v1 continues to report measurements but its red status LED flashes rapidly after startup, the firmware update check may be blocked by your firewall or IoT VLAN.

The local UltimateSensor Mini v1 firmware reads a small version manifest from SmartHomeShop GitHub Pages. This check only determines whether new firmware is available. It does not send sensor readings, Home Assistant data, Wi-Fi passwords or API keys to GitHub.

ESPHome's standard status LED reports errors from every firmware component. A blocked update check can therefore look like a device startup error even while UltimateSensor Mini v1 itself is working normally.

Confirm the cause

Open the UltimateSensor Mini v1 logs in ESPHome and look for http_request.update or Failed to fetch manifest. If these messages are not present, investigate power, network and sensor initialization before changing the update settings.

Disable scheduled firmware checks

  1. Open the ESPHome Device Builder app/add-on in Home Assistant. This is different from the ESPHome integration under Settings > Devices & services.
  2. Find UltimateSensor Mini v1 and select Take control or Adopt.
  3. Save a copy of the generated YAML, including its API encryption key.
  4. Select Edit and add this block at the bottom of the YAML, without extra indentation:
update:
  - id: !extend firmware_update
    update_interval: never
  1. Save the file, select Validate, and then select Install > Wirelessly.

After installation, UltimateSensor Mini v1 keeps measuring and communicating locally with Home Assistant, but it no longer performs scheduled firmware checks. You can still update it later through ESPHome or the SmartHomeShop web flasher.

ESPHome still downloads the UltimateSensor Mini v1 packages: configuration from GitHub while compiling. That request is made by the Home Assistant/ESPHome host, not by UltimateSensor Mini v1 itself.

If validation says that firmware_update does not exist, remove the block again and install a current UltimateSensor Mini v1 firmware version first. A rapidly flashing LED that remains after this change can indicate another real firmware or hardware error.

This guide helps solve common UltimateSensor Mini v1 issues.

Device Does Not Power On

  • Check the USB-C cable.
  • Try another power adapter.
  • Use a stable 5V supply.

WiFi Setup Does Not Open

  • Wait 1-2 minutes after powering on.
  • Look for the ultimatesensor-mini fallback hotspot.
  • Use password ultimatesensor-mini.
  • If the captive portal does not open, go to http://192.168.4.1/.
  • Use a 2.4 GHz WiFi network.

Device Not Discovered in Home Assistant

  1. Check whether the Mini v1 is connected to your WiFi network.
  2. Find the IP address in your router.
  3. Add it manually through Settings -> Devices & services -> ESPHome.
  4. Make sure Home Assistant and the Mini v1 are on the same reachable network.

Voice Assistant Is Not Working

  • Check that the media player entity exists.
  • Select the correct Home Assistant voice pipeline.
  • If you use local wake word, confirm that Mini v1 production firmware 3.0 or newer is installed.
  • Check the Enable Voice Assistant switch.
  • Check Voice Assistant Phase on the device page. It shows not_ready while Home Assistant is not connected.
  • Avoid placing the Mini v1 next to constant noise sources.

Local Wake Word Switch Is Missing

The device is not running Mini v1 production firmware 3.0 or newer. Follow the Firmware Guide; version 2.42 or older first requires the one-time USB-C upgrade.

CO2 or Climate Readings Look Wrong

  • Let the SCD41 stabilize after first boot.
  • Keep the device away from direct sunlight, radiators and ventilation outlets.
  • Use the calibration guide.