# Bluetooth Low Energy

<p class="callout warning"><span style="color: rgb(34, 34, 34); font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Oxygen, Ubuntu, Roboto, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif; font-size: 2.333em; font-weight: 400;">**Please note!**  
Currently, the BLE proxy for SMLIGHT SLZB integration is under development on Home Assistant side and BLE proxy support is expected in the **2026.8** HA release. Therefore, by activating "Proxy advertisements" now, you will not start receiving BLE notifications inside HA until you update HA to 2026.8 release.  
</span></p>

<span style="color: rgb(34, 34, 34); font-family: -apple-system, BlinkMacSystemFont, 'Segoe UI', Oxygen, Ubuntu, Roboto, Cantarell, 'Fira Sans', 'Droid Sans', 'Helvetica Neue', sans-serif; font-size: 2.333em; font-weight: 400;">General information</span>

SLZB-OS supports receiving BLE advertisements for U series and Ultima devices (ESP32-S3 devices).  
**Active BLE connections are not supported.  
Only support passive/active scanning.**

The system consists of two parts:  
\- SLZB-OS with "Proxy advertisements" enabled. Responsible for physically receiving BLE packets and sending them to HA.  
\- SMLIGHT SLZB Home Assistant integration. Manages scanning on the SLZB-OS side, receives raw BLE and forwards them to the HA core.

<div drawio-diagram="214"><img src="https://smlight.tech/support/manuals/uploads/images/drawio/2026-06/drawing-1-1782558783.png" alt=""/></div>

### BLE proxy

<p class="callout info">BLE proxy uses port **5050** so please make sure it is not blocked on your network!</p>

SLZB-OS supports proxying BLE packets to Home Assistant using optimized UDP protocol.

To use BLE proxy you need:

1. Have SLZB-OS **v3.3.3.dev7** or later
2. Have Home Assistant **2026.8** or later
3. Have active [SMLIGHT SLZB integration](https://www.home-assistant.io/integrations/smlight)
4. Have "**BLE**" and "**Proxy advertisements**" enabled in SLZB-OS

[![image.png](https://smlight.tech/support/manuals/uploads/images/gallery/2026-06/scaled-1680-/image.png)](https://smlight.tech/support/manuals/uploads/images/gallery/2026-06/image.png)