So I see where he’s coming from, and I interpreted it as intended.

You can create zones spanning multiple rooms without sensors in each room. Instead of traditional room-by-room motion detection, you could divide your house into zones like "upstairs", "downstairs", or "living area". Especially useful for controlling heating by floor or area-level lighting.

Working through walls also means less clutter. You can hide devices in drawers, closets, or anywhere out of sight.

There's also a pricing aspect: ESP32s can be acquired for a couple of dollars each, so you could have motion sensing throughout your whole house for a fraction of the price of dedicated sensors in every room.

Honestly, it doesn't stand for anything! A couple years ago I was playing around with the concept and a song came on that mentioned "Tommy" repeatedly. I jokingly started calling it Tommy when talking to my girlfriend about it.

So every time the lights turned on or off it was "Tommy who did it" and the name just stuck. Now I'm too invested to change it.

There's a dedicated thread on the Discord channel where people are coming up with good ideas for what TOMMY stands for. Some of the suggestions are "Totally Overengineered Motion Monitoring" and "Through-Obstacle Motion Monitoring". People are still working on what the Y should stand for.

1. As of now it only knows whether there is motion in the zone or not. Actual (x,y) coordinates within the zone are theoretically possible and something I have on the roadmap for 2026.

2. No, it doesn't correlate with other devices currently. But Wi-Fi sensing can theoretically identify who is moving by analyzing how you disrupt the signal. We all have unique movement patterns. I actually have a working proof of concept that can differentiate between me and my girlfriend, but it's very experimental and not stable enough for release yet. Definitely on the future roadmap though.

3. Pretty much instant (around 50ms). The detection happens in real-time as the signal disruption is analyzed.

The interference from running TOMMY is quite low. And if ESP32-C6 (2.4Ghz Wi-Fi 6) or ESP32-C5 (5Ghz) is used as sensors, the interference is negligible.

In the future, when I add stationary presence detection, there is a good chance a small calibration will be needed.

Neighbor detection: I haven't had issues with neighbor movement affecting detection in my testing. The devices form a mesh within your defined zone, so they're primarily sensing disruptions between your own nodes. If you do experience false positives, there's a sensitivity adjustment in the dashboard.

Privacy/spying: In TOMMY, I've explicitly disabled the ability to use devices outside your own network - it only works with ESP32s you've flashed and added to your system. Someone would need physical access to place their own devices in your space.

That said, Wi-Fi sensing as a broader technology could theoretically be used for surveillance if someone controlled devices on both sides of your walls. It's similar to other wireless technologies in that regard. The key is controlling your own hardware.

Even if IEEE doesn't care, someone famous will eventually learn that the walls of their mansion are transparent to passive WiFi receivers with cantennas, even if they turn off all WiFi devices inside their home. Will they build a new mansion with RF-shielded walls? Try to find someone who cares?

"Wi-ESP", papers+code, KITS WRL, South Korea, https://wrlab.github.io/Wi-ESP/

"Espressif CSI sample applications", Shanghai, China, https://github.com/espressif/esp-csi

"CSI-MURDER", paper+code, WiFi Sensing countermeasures, EU, https://ans.unibs.it/projects/csi-murder/