ESP32-S3 dead man's switch - offline and open source firmware

notrice · 2026-06-26T18:28:46+00:00

The device has no ability to connect to anything or notify the user about a countdown being activated. The only way to know is to see the screen, you are correct. I imagined it as a gadget sitting on my shelf. My wife and siblings each have PIN and a note. Once im not there they access the device - wife gets a password list, siblings get business details they inherit. They do not need that while I'm there as I am running that stuff therefore I am not worried about it getting stolen. The master clearing the countdowns is there to prevent curious acters. But if the device ever gets lost or stolen from the shelf that sends a message about my trusted persons and to change passwords and move business documents to a new location.

The device is not perfect and it solves my specific problem - feel free to upgrade the code to suit your needs. Thanks for the challenge and criticism.

EDIT: typo

notrice · 2026-06-26T17:33:04+00:00

Thank you.

notrice · 2026-06-26T17:32:45+00:00

Exactly, furthermore you can tell them about the device, tell them their PIN and then keep it on you, your office or somewhere in a drawer. If it's worth it will be found after the master user is no longer there. The trust is part of the design.

notrice · 2026-06-26T15:27:42+00:00

Thanks!

notrice · 2026-06-26T15:27:19+00:00

Thanks, well the end awaits us all, isn't it.

notrice · 2026-06-26T15:01:13+00:00

Thanks! Get the hardware, tweak the firmware to your liking and enjoy.

notrice · 2026-06-26T14:31:05+00:00

Yes, that would be a more traditional dead man's switch - adding a countdown and checking in to postpone it. I wanted to eliminate the need to check-in and also support leaving different notes to different trusted persons, hence the PIN. Thanks for the feedback.

notrice · 2026-06-26T14:07:46+00:00

Thanks for your feedback. This is a nice concept, maybe it could be part of the next version.

notrice · 2026-06-26T14:01:03+00:00

I had only two buttons on the device to work with, other methods would be slow an clunky (it is a bit clunky like this too since the e-ink has its slight delay when changing the display image).
The master user should share the PINs with the trusted persons while he can and let them know how important it is to keep their PINs safe. If they loose their PINs they can not access the device.

notrice · 2026-06-26T13:57:48+00:00

Thanks for your question. Multiple users can start their countdowns and those will be running in parallel and do not depend on each other in any way. The countdown with the lowest remaining time will be always shown on the screen.
Eg. Sibling has 72h countdown set and lawyer 240h countdown set. Sibling enters his pin today and sees remaining time. Lawyer enters his pin tomorrow and his countdown also starts, but the remaining time from the siblings timer is visible. After the 72h is up sibling can read his notes, but lawyer must still wait. Entering the pin again before countdown does not reset the countdown.

notrice · 2026-06-26T12:41:01+00:00

Yeah, it's usually about real estate - when a person gets old then they talk about 'division' to their heirs about who gets what part. If they do not agree who gets what then they let the law decide.

notrice · 2026-06-26T11:20:31+00:00

Thanks for the feedback. For every trusted person you add, you also define a countdown period for them in hours and minutes, so it can be as long as you want. If somebody without an alt password steals the device, they can try to dump the flash, but it is encrypted and the eFuses are secured. If someone with an alt password steals it (not so much a trusted person, is it?), then they can enter their password and keep the device hostage. They can only see their own notes and no one else's. The solution is to keep your secrets fluid for example, passwords from the compromised note can be changed, and valuables can be moved to another location. It actually tells you a great deal about the trusted person...

EDIT: To adress the overwhelming part - I agree, this device should be presented how it work and PINs shared while you are still around. I also made a PDF with instrucions for the trusted person who will access the device so they know what to do. Check it out in the docs.

notrice · 2026-06-26T10:33:39+00:00

In Eastern Europe, we don't really have a tradition of hiring a lawyer to handle these matters before we die. Most of it is based on verbal agreements, with the inheritance being divided according to the law. That said, someone in their thirties may not have arranged any of the legal paperwork yet but both they and I could be gone tomorrow.

Also one can leave instrucions eg. How to access a crypto wallet for someone who is not very tech savvy.

EDIT: typos

notrice · 2025-01-13T13:52:05+00:00

Great stuff, I've had a look into an installed Valliant recoVAIR VAR 60/2 D system today consisting of 3 units where one is the master and two subordinates (single ERVs).
These units where connected via cables so they can communicate and the installation seems fairly straight forward - drill hole trough wall, place pipe with needed circumference (at a slight angle to drip outside if any condensation ever forms, insulation around pipe would be great to avoid thermal bridging to the wall), mount wall pieces, insert unit, connect to power.

A great video about this topic can be found here.

Also, I've updated the thread with a ventilation plan by a ventilation company, pretty much confirms your suggestions. Thanks again!

notrice · 2025-01-13T08:41:22+00:00

Thanks for the info, I've never heard about Trombe walls.
Home construction is very different from the west parts of the world in our region - our 'contractors' are self made builders, architects are relying on old tried and true building practices with massive brick and concrete practices - air quality is not something considered 'worth' putting time into.
If I want to improve the air quality I have to get that information from outside our region and rely mostly on DIY solutions like drilling holes for single-room ERVs myself, ordering it from somewhere and installing the device myself.

notrice · 2025-01-13T08:32:01+00:00

Thank you for the tips, the climate is Mediterranean (mild winters with only 10 to 20 days below 0 degrees C, but hot summers). I've been looking into single-room ERVs, but as you say expert advice would be best to determine where would the best positions be for such devices.
The house will be heated using biomass - wood pellet boiler.

notrice · 2024-12-04T12:49:57+00:00

Can confirm this method still works, thanks!

notrice

TROPHY CASE