Ukranian controls Home Assistant over LoRa radio when their power grid goes down

Source: Hacker News

Introduction

Hey r/homeassistant,

I live in Ukraine. Russia regularly attacks our power grid — when it goes down, internet and cell towers follow within hours. My Home Assistant keeps running on battery backup, but I can’t reach it from outside. So I built a radio bridge.

How it works

Two Lilygo T‑Echo radios (~$30 each, LoRa 433 MHz, Meshtastic firmware). One is plugged into my Mac mini via USB, the other is portable with me. A Python listener daemon sits between the radio and Home Assistant, routing commands and returning sensor data — all over encrypted LoRa. HA runs on a Home Assistant Green.

What I can do from the radio

Smart home control

• Turn lights on/off
• Check temperature from Aqara sensors (three around the house)
• Check power status — grid on/off, battery levels (EcoFlow, Zendure)
• Check who’s home

Voice messages (the fun part)

1. Type SAY: Привіт, я скоро буду вдома (Hey, I’ll come back home soon) on the T‑Echo.
2. Listener calls tts.google_translate with Ukrainian language.
3. HA Voice PE speaker reads it aloud at home.

Zero internet. Just radio → Mac mini → HA TTS → speaker.

Camera snapshots

• Ask “what’s outside?” via radio or Discord.
• Listener grabs snapshots from Tapo C120 + C100 (via HA camera proxy API).
• Runs them through a local vision model (gemma3:12b on Ollama).
• Sends a text description, e.g., “5 cars parked, no people, snowy”.
• Hourly automated monitoring logs everything.

Proactive alerts

• The AI monitors power status.
• Power goes out → LoRa message to my radio within seconds, plus battery levels and temperature.

The HA integration

The listener talks to HA through the REST API:

• GET /api/states/{entity_id} — read sensors
• POST /api/services/{domain}/{service} — control devices
• GET /api/camera_proxy/{camera_entity} — grab snapshots
• POST /api/services/tts/speak — voice messages

Incoming radio messages are classified by a local LLM (phi4‑mini) — “is this a smart home command, a question, or a TTS request?” — then routed to the appropriate HA service or to a larger model (gemma3:12b) for general questions.

Architecture

T-Echo (portable)
    │ LoRa 433 MHz, encrypted
    ▼
T-Echo (USB) → Mac mini
    │
    ├── SAY: prefix  → tts.google_translate → Voice PE speaker
    ├── Smart home   → Home Assistant REST API
    ├── Camera       → camera_proxy → gemma3 vision → description
    ├── AI questions → phi4-mini → gemma3:12b (local via Ollama)
    └── Alerts       → outbox .msg files → LoRa TX

Why this matters

HA on battery backup is great, but useless if you can’t reach it. The radio bridge means:

• No dependency on Wi‑Fi, internet, or cell towers
• Encrypted communication (Meshtastic PSK)
• ~1–3 km urban range with stock T‑Echo antenna (extendable with mesh nodes)
• Total cost: ~$ 60 for two radios

Entities I use

• camera.tapo_c120_hd_stream / camera.tapo_c100_hd_stream — snapshots
• tts.google_translate_en_com (with language: "uk") — Ukrainian TTS
• media_player.home_assistant_voice_* — the speaker
• binary_sensor.tapo_c120_person_detection — triggers
• Aqara temperature sensors
• Power grid status sensor (via Yasno integration and Meross Smart Plug as a sensor)
• EcoFlow battery levels

Stack

• Home Assistant — the heart of it all
• HA Voice PE — TTS output speaker
• Tapo C120 + C100 — security cameras
• Meshtastic on Lilygo T‑Echo (433 MHz)
• Ollama — local AI models
• OpenClaw — AI agent framework
• Mac mini M4 — server on battery backup

Happy to answer questions about the HA setup.