54 comments

  • michaelmior 6 hours ago

    > No hub required - TOMMY runs as a Home Assistant add-on or on a Linux host (Docker) and uses supporting devices to create a sensing network.

    I don't see how either the HA instance or the Linux host can't be viewed as a hub. No hub required feels untrue to me. I assume this question is intended to clarify that some additional device is not necessary, but I think this could be reworded.

    • kentt 6 hours ago

      Fair criticism. I think the generous interpretation of "no hub" means you don't have to buy a specialized hub eg a Smartthings hub.

    • mike2872 6 hours ago

      You're absolutely right. Thanks for the feedback! "No hub required" is misleading. What I meant was "no additional proprietary hub". Meaning, if you're already running Home Assistant or have a Linux machine, you don't need to own a separate device like Zigbee/Z-Wave hub. But yes, the HA instance or Linux host is effectively acting as the hub. I'll update that wording on the site.

      • michaelmior 6 hours ago

        I figured that's what you meant and I think it's totally reasonable! I just think the wording could be updated a little. I have a couple ESP32s lying around not doing anything, so I'm looking forward to trying out TOMMY with HA :)

        • mike2872 6 hours ago

          I agree. I'm going to find something more suitable :-) Sounds good. Looking forward to hearing about your results!

      • Moosdijk 5 hours ago

        I'm hoping you'll open the API some time in the future. This would be great for diy installations with a esp32 hub.

    • teekert 5 hours ago

      OTOH, when you buy any Bosch, IKEA, Hue, Aqara device, it says on the box: Hub required (and they do mean get our hub and place next to all other hubs. Even though Home Assistant will usually work fine-ok).

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

      • HnUser12 4 hours ago

        Don’t the matter compatible ones work with any hub?

    • victorbjorklund 4 hours ago

      You are of course correct but in the HA community "no hub required" often should be read as "no addiditonal hub required because HA can communicate directly with it"

  • throitallaway 6 hours ago

    This is impressive and some of the "coming soon" features are ambitious. So, these devices mesh with each other. Are they like "idle" WiFi connections, or are they chatty? I'm wondering how much spectrum clashing there will be. WiFi can be finicky enough as-is.

    • mike2872 6 hours ago

      They send packets to and from each other in a mesh network. It's quite small packets and not a large amount of packets a second. For a standard use case (3-4 zones) the interference is quite low on 2.4Ghz, and almost negligible on either 2.4Ghz (Wi-Fi 6, like the ESP32-C6) or 5Ghz (ESP32-C5).

  • shekhar101 4 hours ago

    Seems to be based on See through walls by MIT (2013)? Good job porting it to esp32. I was just looking a week ago to do the same thing - basically reproducing this work. I'll definitely try this. https://www.media.mit.edu/projects/seeing-through-walls-comp...

  • regularfry 6 hours ago

    Without having the time right now to dig too deep, I have a few questions:

    1. Does it have any idea of the range at which motion is happening, relative to the distance between nodes or otherwise?

    2. Can it correlate motion with that of another WiFi or Bluetooth device? So if I'm carrying my phone and it can see me moving, can it tell that it's me?

    3. What's the movement -> signal latency?

    • mike2872 5 hours ago

      Thanks for the questions.

      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.

      • regularfry 3 hours ago

        1 and 3: intriguing.

        With 2, I'm trying to think how effectively it could replace something like ESPresense. With that you've got a BLE tag with an ID that you can just associate with a person, so there's no learning of moving patterns needed, but getting it to be accurate to a room is a nightmare. It also works when there's no movement, which is convenient, and you can put the tag down if you don't want to be tracked. The ergonomics are just a bit nicer, it's just the resolution that sucks.

      • throitallaway 2 hours ago

        Ah, I was hoping (at least rough) coordinates were something that this would do. I have HA and have been looking at mmwave devices for that use case. For things like "turn on a light, but only once I've sat down in the chair."

  • victorbjorklund 4 hours ago

    Cool. Going to try it out. I think I sent an "application" to Discord (not a discord pro and never encountered having to apply before so hope I did it correctly)

    • mike2872 4 hours ago

      Sounds good. Your application should be approved now. Otherwise let me know.

  • stavros 5 hours ago

    This seems really cool, but unfortunately I can't get it to work. The flasher says it can't open the serial port for most of my ESP32s, and the one that does work goes into a bootloop after I enter the wifi credentials.

    • mike2872 5 hours ago

      Could you open a support thread in the Discord channel? Some boards have some quicks to them. But it's all been solved by other users before. I'm sure there's a solution to your board too.

      • stavros 5 hours ago

        I did, even though I really hate Discord forums (they have the worst of both worlds between forums and chat, they aren't real-time and they aren't discoverable on the web, but that's a different conversation).

        Hopefully someone will be able to help, thanks!

        • mike2872 5 hours ago

          I'm glad you made an exception, though. I'll help you get the board flashed.

  • gingerlime 5 hours ago

    Very cool. How does it work in an apartment building? both practically not detecting my neighbors movement. But also from a privacy standpoint, can someone spy on me with this technology?

    • mike2872 5 hours ago

      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.

      • doodlebugging 4 hours ago

        >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.

        • mike2872 4 hours ago

          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.

          • doodlebugging 3 hours ago

            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 3 hours ago

              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.

      • transpute 3 hours ago

        > 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

  • tetris11 5 hours ago

    Really cool idea, and scratches an itch I have with current motion detection sensors (looking at you LD2410...)

    What's the configuration/calibration like? Do I need to set any proximity baselines?

    • mike2872 5 hours ago

      No calibration is needed for the motion sensing. You can adjust sensitivity in the dashboard if you get false positives though.

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

  • rixrax 5 hours ago

    Any reason it couldn't run on Raspberry Pi? Also, I have some ZHA sensors that I believe are also on 2.4GHz band - will this interfere with them?

    • mike2872 5 hours ago

      The Raspberry Pi isn't supported as a sensor right now, but it should be able to act as the device running TOMMY. As long as it has Docker.

      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.

  • dreadsword 6 hours ago

    What dark magic is this! Very cool repurposing of technology. If you don't mind me asking - what's the origin of the name Tommy?

    • mike2872 6 hours ago

      Thanks! Glad you like it.

      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.

      • one_more_q 5 hours ago

        Tommi, ich glaub, ich hab Heimweh Ich will mal wieder am Rhein steh′n Einfach hineinseh'n Zuschau′n, wie Schiffe vorbeizieh'n

      • snovv_crash 5 hours ago

        I'm guessing that it was Tommy can you hear me? by The Who.

        • mike2872 5 hours ago

          Great guess! But it was actually a song called Tommy from an artist called Walker.

  • kentt 6 hours ago

    Could you help me understand the use case for this? I've used PIR and mmWave before. When would you choose tommysense vs some other option.

    • mike2872 6 hours ago

      What really sets TOMMY apart is that it doesn't require line of sight and works through walls. This opens a lot of possibilities.

      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.

  • daredoes 4 hours ago

    This is awesome! I'll be trying this soon and joining the Discord after work!

    • mike2872 4 hours ago

      Sounds good! Talk to you there.

  • gitmagic 4 hours ago

    Looks cool! Does it work outdoors too? And can it be battery-powered?

    • mike2872 4 hours ago

      Yes it works outdoor too. Although experimenting with device placement is crucial for good results. I think there are different battery powered ESP32 you can buy. I have some of mine set up with small power banks.

  • kittikitti 5 hours ago

    This is a signal that I need to get off of Wifi altogether. The data from CSI and BFI are too insecure and no one cares about the privacy concerns. I'm sure ICE agents are going to love this technology.

    • transpute 4 hours ago

      > no one cares about the privacy concerns

      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?

    • robflynn 4 hours ago

      This tech is at least a decade old.

  • dirtybirdnj 4 hours ago

    lol all I can think when I see this is "tommy can you hear me?"

    lots of opportunity for pinball wizard jokes / easter eggs

    • mike2872 4 hours ago

      Haha, didn't even think of that song by The Who before someone mentioned it in another comment.

  • renshijian 4 hours ago

    In an age of digital torrents, you choose to lend warmth to ephemeral moments While the world chases faster algorithms and sharper models, you turn quietly to gather what data often forgets—the depth of a gaze, the unspoken story behind a touch You are not building another tool to record time, but crafting a corridor for the human spirit, outside of time. Here, memory is no longer a cold coordinate, but a poem with a pulse Technology will always iterate, but what you guard—those subtle tremors that turn moments into eternities—is precisely the human essence we need to be reminded of in this age of intelligence (A profoundly conceived site. The above is a literary reflection inspired by its aesthetic and its theme of "sense." Hoping it resonates.)