Tommy - Turn ESP32 devices into through-wall motion sensors

What it does

Tommy is a Wi-Fi sensing system that turns ESP32 devices into through-wall motion and presence sensors. It uses Channel State Information (CSI) from Wi-Fi packets to detect motion and stationary occupancy (including breathing) through walls, furniture, and floors. The system runs entirely on local hardware, with no cloud dependency for sensing data. It integrates with Home Assistant (via MQTT) and Matter (as an occupancy sensor).

Who it is for

Tommy is designed for Home Assistant enthusiasts, smart home builders, and makers who want privacy-preserving, through-wall presence detection without cameras or dedicated sensors. It requires at least two ESP32 boards per zone (supported variants: ESP32, C3, C5, C6, S2, S3). The C5 is recommended for optimal presence detection due to its 5 GHz support. Users should be comfortable flashing firmware and configuring zones via the Tommy dashboard.

Why it matters

Traditional motion sensors (PIR) require line-of-sight and cannot detect stationary occupants. Tommy uses Wi-Fi signals to sense through walls, enabling whole-home occupancy detection with a single set of devices. All data stays local, addressing privacy concerns. It also offers a unique "boundary" mode to reduce false positives from neighboring rooms. The system is open about its limitations: the core is closed-source, but a network bounty program and offline activation guarantee are provided.

Launch signal

Tommy was launched as a Show HN on Hacker News, indicating early-stage public availability. The website offers a free trial (with detection pauses every 2 minutes) and a paid Pro license for uninterrupted detection. The product is actively maintained with documentation, a roadmap, and community support via Discord and GitHub.

Brand and naming

The name "Tommy" is short, friendly, and memorable, contrasting with technical names like "ESP32 Wi-Fi Sensor." It positions the product as approachable for hobbyists. The tagline "Turn ESP32 devices into through-wall motion sensors" clearly states the value proposition. The brand emphasizes privacy, local control, and community trust through transparency about closed-source components.