Show HN: Tommy – Turn ESP32 devices into through-wall motion sensors • Hacker News Board

Re: Show HN: Tommy – Turn ESP32 devices into through-wall motion sensors

#81

Post by mike2872 » Sat, Oct 25, 2025, 3:50 PM UTC

cassettelabs wrote: post #77

Congrats on the launch, that looks really cool! I had an idea to build a restricted zones for a phone. For example, I can't take my phone to bed, so I wanted to create a esp32 based project that beeps when the phone is too close to some areas. I made it based on BLE, but iphone masks MAC addresses, so it was impossible to track particular devices. No I realize, I could actually do it with WIFI signal straight. How I…

Thanks! I'm glad you like it.

Sounds like a great project. Using the Wi-Fi signal directly might work in your case. It would be nice to go back to actually using the bedroom as a place to sleep and not look at the phones all the time :-)

Re: Show HN: Tommy – Turn ESP32 devices into through-wall motion sensors

#82

Post by mike2872 » Mon, Oct 27, 2025, 12:58 PM UTC

joshstrange wrote: post #79

What would you recommend/what do people do for power and access for in-wall sensors? Pulling power at least once per room (assuming you can share at least 1 node with another room) and being able to access it if you need to reflash feel like hard problems. OR, am I completely missing the point that it's "through walls", not necessarily in-wall (though that would work). A wall-wart-sized device containing the ESP32 bo…

It's possible to have the devices in-wall, but it might not be that practical as you point out. Or at least they would have to be taken out once for flashing, then OTA updates would reduce or eliminate the need for reflashing further.

The real benefit from the sensors working through walls in my opinion is to be able to hide the devices away (e.g. in a closet or drawer) + being able to create zones that crosses walls. Image wanting a zone called 'upstairs', 'downstairs', 'garage' etc. which consists of multiple rooms divided by walls. Instead of having a sensor in each room you might just need one on each side of the total area.

Thanks! I agree with the PiR and mmWave limitations. Right now I think this project can replace motion sensor. Hopefully mmWave when stationary presence detection is added (planned Q1 2026).

Re: Show HN: Tommy – Turn ESP32 devices into through-wall motion sensors

#83

Post by mike2872 » Mon, Oct 27, 2025, 1:04 PM UTC

atmanactive wrote: post #76

mike2872 wrote: post #75

Earlier quoted context omitted.

Actually, you are right. I confused myself. You would need to have them connected to the same Wi-Fi as that determines the bands and channels they communicate on even though the communication is peer-to-peer. How are your devices connected exactly? Using ethernet on the subnet your HA instance is on? And are you then able to also connect to a separate Wi-Fi SSID you create for those devices? Also, are you able to joi…

Thank you for the explanation. Right now I don't have Tommy or any of it's devices configured (yet). I was just trying to determine what's possible and what's not. I do have ethernet throughout the house. Then, I have three Ubiquity AmpliFi dual-band mesh WiFi access points in an ethernet-backboned configuration. I do a lot of Sunshine/Moonlight low-latency high-def video/audio streaming, so for me, the WiFi quality/…

I can understand that. I used to do a lot of game streaming with Parsec and ended up with a similar setup.

Right now, TOMMY only use Wi-Fi and doesn't support using ethernet for the communication with HA and Wi-Fi for peer-to-peer communication. But that is very possible to implement. Just haven't encountered the use case before now.

I'll probably implement an option for split communication (ethernet, wifi) and then allow users to decide the Wi-Fi channel devices communicate on peer-to-peer. That way you'd have full control over possible interference.

Re: Show HN: Tommy – Turn ESP32 devices into through-wall motion sensors

#84

Post by michaelmior » Wed, Oct 29, 2025, 12:57 PM UTC

victorbjorklund wrote: post #39

michaelmior wrote: post #3

> 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.

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"

Agreed although I think it would still help to be more explicit.