Shelly Plus 1 DIY 12V Siren Driver

Quick verdict

A Shelly relay wired to any 12V piezo/strobe turns a cheap industrial siren into a fully local, hub-free Home Assistant siren. The Shelly relay is controlled directly over the LAN by Home Assistant with no cloud dependency. Just note: DIY wiring required; not a turnkey siren.

Standout: A Shelly relay wired to any 12V piezo/strobe turns a cheap industrial siren into a fully local, hub-free Home Assistant siren.

Last checked: 2026-06-02

Compatibility snapshot

Why it stands out

• 100% local control with Shelly's HA integration and auto-discovery
• Use any loud 12V wired siren/strobe, indoor or outdoor
• No additional hub; runs even if internet is down

Reasons to hesitate

• DIY wiring required; not a turnkey siren
• On/off only (no tones/volume) unless the siren supports it
• You must source the physical siren/strobe separately

Best for

• Tinkerers wanting a loud, cheap, fully local wired siren

Avoid if

• you want a finished, plug-and-play product rather than a DIY/wiring project

Privacy and local-control notes

The Shelly relay is controlled directly over the LAN by Home Assistant with no cloud dependency.

Home Assistant support: supported · integration path: Shelly (local).

Buying reality check

Price notes: Around $20. Among the more affordable options in this category.

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