FAQ

Can the radar see through walls?

Millimeter wave penetrates non-metallic materials like curtains and thin wooden doors to some degree, but concrete walls and metal cause severe attenuation. Mount the radar facing the monitored area; don’t place it behind a load-bearing wall.

Does it need the cloud? Where does data go?

No. The radar reports over a local MQTT broker (e.g. Mosquitto / Artemis) and by default never leaves your home network. Going to the cloud is optional and up to you.

How is privacy? Compared to a camera?

The radar only outputs point-cloud-level info like distance, speed, and presence / fall state — no video, no audio, far more privacy-friendly than a camera. Great for bathrooms and bedrooms.

Must it use 2.4GHz Wi-Fi?

Yes. Provisioning uses 2.4GHz Wi-Fi only, not 5GHz. Make sure your router has the 2.4G band enabled (many dual-band routers merge bands by default and need to be split in settings).

How do I connect the radar to Wi-Fi (provisioning)?

Two short setups, both done once and stored in the module:

1. Set the MQTT broker — press the button for 10 s, join the RadarConfig Wi-Fi hotspot, open 192.168.0.1, and enter your broker address, port, ClientID, username, and password. (The Android app has no MQTT fields, so this must be done on the hotspot page.)
2. Send the Wi-Fi credentials — install BK_BLE5.apk (Android only; there is no iOS app), press the button for 5 s until the LED flashes, then in the app grant location permission and send your 2.4 GHz Wi-Fi SSID and password over Bluetooth.

Gotchas:

• 2.4 GHz only — 5 GHz / 5.8 GHz cannot be used. If your router merges bands, split them or use a separate 2.4 GHz network.
• 90-second timeout — if provisioning does not finish in time, hold the button again to retry.
• The app is Android-only; the WeChat mini-program used in China is not available outside China, so use the Android app.

Full walkthrough with screenshots and a troubleshooting table: Wi-Fi Provisioning & MQTT Setup Guide.

How do I choose the voice / alarm language?

The firmware supports Chinese / English voice prompts; switch in the companion app or a config item. See each product guide.

How do I connect to Home Assistant?

See Home Assistant Integration (Verified) and the per-model HA guides.

What are the power and mounting requirements?

See Sleep Radar Mounting Position.

How much latency / how real-time?

See Why mmWave Radar Takes Seconds to Respond.

Are the advertised detection range / angle numbers reliable?

See Three mmWave Radar Specs That Are Almost Always Exaggerated.

How does it work? How does mmWave measure breathing / falls?

See How mmWave Radar Works.

Which one should I buy?

See Which 60GHz Radar Should I Buy?.

Specifications: size, power supply, and wireless

All three finished 60 GHz units join your network over 2.4 GHz Wi-Fi + MQTT. The bare 24 GHz modules use UART only (no Wi-Fi, no network to configure).

Each product guide has its own ## Specifications table with the full parameter list (beam angle, current, detection range, etc.). Mounting detail: Sleep Radar Mounting Position.

What protocol and interface does it use?

Two families ship from this store:

• Finished 60 GHz radar — connects over 2.4 GHz Wi-Fi and reports a JSON property protocol over MQTT topics. Configure it from a web page (for MQTT) or the Android app (for Wi-Fi), then read it from any broker (Mosquitto / Artemis). See Home Assistant Integration (Verified).
• 24 GHz radar module — a bare sensing core with UART only, speaking a binary frame protocol at 115200 bps, 8N1, 3.3 V TTL. No Wi-Fi, no account; any serial terminal or USB-TTL adapter talks to it. This is the path for embedding the sensor into your own product.

Full comparison: Two Architectures, Two Protocols: MQTT vs UART.

Still have questions?

Leave a message on our Tindie store or open a GitHub Issue.