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IEMI Labs
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SensingStage 2 ready, 29 Oct 2026 (rev A, 28 Oct): smart guest-room thermostat that runs the room itself (8 calls, 6 alone, 2 assist), call light and tone, ATECC608 and tamper switch inside; 7 radar views checked in the CAD; not built

RoomOne

IEMI's one product for a hotel guest room: the room's own thermostat, made smart

The guest room's wall thermostat by the entry, at the same size, place and wiring, knows when the room is really empty from a radar that sees breathing: it sets the PTAC or fan coil back by the energy code and brings the guest's set point back on entry, records smoke and vape events with a signed particle curve, records a covered or removed thermostat, dries a damp room, and moves the room to the clean list after checkout. No camera and no microphone.

Who buys it
Owners, general managers and chief engineers of select-service and extended-stay hotels, motels and serviced apartments with PTACs or fan coils (50 to 300 rooms); then hotel groups at renovation.
Why it pays
$349 + $8/room/month instead of about $673 + $13/room/month for a guest-room thermostat, a GuestRoom node and a VapeSense disc bought separately (est.).
Target price
$349 per room (replaces the room's thermostat) + $8/room/month hotel app (target)
First-minute wow
A guest leaves 412 for a meeting at 13:00. At 13:20 the thermostat sets the room back to 26 C; at 17:40 the door opens and 22 C is back before the bag is down. That night 307 vapes at the desk, and by 23:15 the manager has a signed particle curve, not a housekeeper's guess.
See the CAD designConcept page
RoomOne concept: the idea and where each part goes
The concept. The CAD design is below, under Printable CAD.

What the research found

And how this design answers it

  • Rev A (28 Oct 2026): the facilities and hospitality flagship is the guest room's own thermostat. Inside it: a XIAO ESP32-S3 brain, a Sensirion SEN66 air module, an HLK-LD2410C breathing radar, a 2.13 in e-paper, two keys, a call light, a tone, ATECC608, tamper switch, three HVAC relays and 24 VAC power
  • Makes the room's calls itself: set back when really empty, guest back, smoke or vape event, thermostat covered, damp dry mode and clean now alone; smoking fee and welfare checks go to a person; unsure means 'air event, check room'
  • Legal on the wall: keys in the ADA 308 reach range, 32 mm off the wall (ADA 307.2), set back within 30 min of the room going empty (ASHRAE 90.1 6.4.3.3.5, Title 24 120.2(e)4)
  • Privacy first: no camera and no microphone in a sleeping room; radar presence only
  • Market and rules check (30 Oct 2026): sensor-only smoking fees were reversed in 2026 news reports, so the fee evidence now sets the air curve beside the radar presence log (room empty: do not charge; humidity rising: styling or steam likely), the hotel's posted policy beside it (FTC fees rule), and a guest notice on the screen and wall plate; no new part
  • Folds GuestRoom and VapeSense; laundry rooms, building leaks, back-of-house floors and care homes stay with their own zones

Use case

A 120-room select-service hotel with one night auditor

General managerChief engineerHousekeeping leadNight auditor

  1. 01Trigger: a guest leaves, sleeps, vapes or checks out
  2. 02Detect: the radar reads presence and breathing; the air module reads particles, VOC, humidity and CO2
  3. 03Act: set back or comfort on the PTAC, red light and tone for smoke or vape, dry mode, clean list
  4. 04Log: one signed event list and a weekly energy report per room

Outcome: Empty rooms are set back without waking sleeping guests, and every smoking fee has signed evidence

How it works

Architecture

  1. 01

    Sense: a breathing radar and an air module inside the thermostat

  2. 02

    Decide: the XIAO ESP32-S3 runs the presence state and the air-event classifier; 'air event, check room' below the line

  3. 03

    Act: fan, cool and heat to the PTAC over its own 24 VAC wires

  4. 04

    Tell: the call light and tone in the room, and one signed event list to the hotel app

Hardware

Real parts, buyable today

Bill of materials: about $146 per room at qty 1 (checked 29 Oct 2026); cost about $163, margin about 53 % at $349 (est.); replaces the room's thermostat.

BlockPartWhy this part
BrainSeeed XIAO ESP32-S3Runs the room rules and the HVAC; Wi-Fi to the hotel app
PresenceHi-Link HLK-LD2410C 24 GHz radarSees a sleeping guest by breathing, so no false set back
AirSensirion SEN66Smoke and vape, damp, CO2 and the room temperature
HVAC3 x Omron G5V-1 + Pololu D36V28F5Fan, cool and heat on the same wires; power from the 24 VAC
FaceWaveshare 2.13 in e-paper, 2 x Adafruit 1441, NeoPixel Stick 8, Adafruit 160Set point, keys, call light and tone
SecurityAdafruit 4314 ATECC608 + Omron D2F-01Signed calls, tamper log

Mechanical

Printable CAD

2 parts, generated from code and checked as closed solids. Pick a part to inspect it, or download the STL files to print.

Loading the CAD…

Real CAD · drag to rotate · scroll to zoomReal CAD · swipe sideways

Open risks we are working on

  • Smoke and vape reaching the wall from the far end of the room needs a timing test in real rooms (est. under 3 min)
  • Breathing detection through a 1 mm PC-ABS window at 5 m needs a bench test
  • Steam from the bathroom and hair spray must never be called smoking; the classifier is unproven until field data
  • PTAC and fan coil wiring varies; some PTACs need their own remote-thermostat kit
  • UL 60730-2-9 and radio tests are still to be done; it is not a smoke alarm and makes no safety claim

Design stage only: nothing on this page is for sale. Specifications and prices are targets.