Great questions.

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.

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doodlebugging 12 days ago | parent | next [-]

>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.

Does this mean that a nosy neighbor or someone else who wanted to surveil your residence could accomplish this by placing multiple devices around but not necessarily on your property so that a mesh is created that effectively covers your residence? Sounds like a stalker tool or a tool for burglars to use to determine when a building is unoccupied so that they can get in and out without being interrupted. Wealthy homeowners, like professional sports players, have already become targets of burglars who use team schedules to understand when a place will be unoccupied. The NFL's Joe Burrow I think is the most recent victim.

I guess the effective range of each device factors into this if you were determining mesh coverage.

How would one protect their residence from similar surveillance?

EDIT: I like this concept and see that this could help me here in managing deer traffic across my property. I would like to give them a reason to take another path so knowing exactly when they are on the property is useful data. Game cameras and ordinary security cameras set up as game cameras have a noticeable lag and so they don't send the alert until they finalize a video and by that time the animal has absconded, but not before chewing my fruit trees.

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mike2872 12 days ago | parent [-]

While theoretically possible, this would be a very involved surveillance method compared to simpler alternatives that already exist (cameras with telephoto lenses, thermal imaging, simply watching schedules, etc.). Wi-Fi sensing isn't easier or more covert than existing methods. At the current state of the technology, other methods are far more suitable for people who want to spy on others.

The effective range of each device factors into the sensing area. The closer together the sensors are the higher sensing sensitivity it has. In my 90 square meter apartment I can create a sensing area with a sensor in each end of the apartment.

Additionally, TOMMY is designed to only work with devices you've explicitly flashed and added to your system. It won't interact with random ESP32s that might be nearby.

The deer management is actually a very interesting use case. I am interested in hearing your results if you decide to set it up for that.

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doodlebugging 12 days ago | parent [-]

Thanks for the thoughtful reply. A long time ago there was a paper published, by MIT I think showing a similar setup to use WiFi as a surveillance tool for motion detection through walls. It was interesting at the time and something that I have thought about quite a bit over the years without ever actually doing anything myself. I think at heart I have been waiting for someone like yourself to make it all easy enough that someone like myself, who already has too many things on their plate, can jump in and begin using it without having to solve all the initial issues. Thanks for doing this work.

For my own use case as simple mesh array that would alert me to movement within certain parts of the property that I have set aside as garden or orchard plots would really be useful. I have lost numerous fruit trees to deer, especially in winter cold spells and over time learned that the only effective method of guaranteeing plant survival over winter is area denial. I accomplished this over the last couple of years using deer fencing products to establish areas where large animals have no access. In the process, I also found a use case for a security camera to monitor an area to see which animals regularly passed by or through.

Over a period of years I have seen lots of animal tracks but direct sightings have been rare. Using the security camera as a game camera has restored my confidence in animal ID from tracks alone since I have managed to capture still photos and video of the animals that I was pretty sure were visiting my place to validate what I believed based on the tracks alone. I hunted and trapped when I was a kid into high school so it is good to see that, though I have not needed them and have rarely used them, I have not totally lost those skills in the ensuing 40+ years.

I can see an array like this as quite useful in a garden space for identifying which plants need protection from squirrels, opossums, raccoons, etc and where the feral cats are squatting so that I don't inadvertently dredge up something unwholesome while working the soil. My cameras have demonstrated that they can detect and alert to things as small as a wasp or beetle moving across the FoV so if I can set something up to track the path of grasshoppers through the garden then I can potentially see where they are laying eggs cases and disrupt that soil before they can hatch next season.

This is all really interesting stuff. I look forward to joining the Discord group and to picking up a few ESPs for testing.

Sorry for the wall of text.

	▲	mike2872 12 days ago \| parent [-]
		That was also one of the papers I read early in my project. Really fascinating stuff. The use cases for Wi-Fi sensing are vast. Motion and presence sensing is only scratching the surface. My goal is for TOMMY to follow this technology and make it accessible to everyone, especially in the smart home space. Your garden/wildlife management use case is very interesting. Way more creative than typical smart home automation. The real-time detection should help with that camera lag issue you mentioned, and the through-wall sensing could monitor areas that are hard to place cameras. Please create a thread in the Discord channel about this use case. I think it's really interesting and other users might have good ideas for your setup. Would love to see how it works out for you! No apologies needed for the wall of text. This is exactly the kind of creative applications I was hoping people would think of.

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transpute 12 days ago | parent | prev [-]

> Wi-Fi sensing as a broader technology could theoretically be used for surveillance if someone controlled devices on both sides of your walls.

Wi-Fi sensing is passive, i.e. only one side of the wall is needed.

https://news.ycombinator.com/item?id=45488908#45546394

	▲	mike2872 11 days ago \| parent [-]
		From my understanding, Wi-Fi sensing requires at least two antennas (transmitter and receiver) to measure signal disruption. This could be one device with both antennas, or two separate devices. There are also techniques that use one controlled device and leverage ambient Wi-Fi signals from uncontrolled sources (like a neighbor's router), but TOMMY explicitly disables all options for using devices outside your own network. It only works with ESP32s you've flashed and added to your system.