ColdRoom

How it fits together

ColdRoom, part by part

Scroll or tap a part. Press “See the 3D CAD design” to watch the model, built from our CAD, light each part up and show how it connects.

See the 3D CAD designShow the concept

Real-time 3D render · drag to rotate · final design may varySwipe sideways to rotate

1. 01

   The whole ColdRoom

   One hub above the walk-in door reads the probes and door, keeps the record and photographs the shelves, over Wi-Fi or LTE-M.

2. 02Brain

   Seeed XIAO ESP32S3 Sense

   The brain: it runs the coldroom-fw program

3. 

   03

   Air and product probes

   Read air and glycol-bottle temperature every minute

   Seeed XIAO ESP32S3 Sense · 1-Wire (3-wire cable) · Two temperatures

4. 

   04

   Door reed switch

   Tells the hub when the door opens or shuts

   Seeed XIAO ESP32S3 Sense · GPIO interrupt pin · Door open or shut

5. 05

   OV3660 shelf camera

   Photographs the shelves every 30 minutes with the door shut

   Seeed XIAO ESP32S3 Sense · Camera board connector (DVP) · Still photos

6. 06

   SHT45 humidity sensor

   Shows frost and door-seal trouble as humidity

   Seeed XIAO ESP32S3 Sense · I²C (on the board) · Humidity, board temperature

7. 07

   DELIVERY key

   Marks a delivery and starts the receiving record

   Seeed XIAO ESP32S3 Sense · GPIO pin · Key press

8. 

   08

   LTE-M modem

   Sends alerts when Wi-Fi or mains is down

   Seeed XIAO ESP32S3 Sense · UART (AT commands) · Readings and alerts

9. 

   09

   USB-C power, AA backup

   Mains from outside; two lithium AA cells for weeks of backup

   Seeed XIAO ESP32S3 Sense · 5 V power lead · Power

10. 10

    All connected

    8 key parts, one program, and your phone

How the parts connect

ColdRoom, wired up

Every part, what links it to the brain, and how the data reaches your phone. A solid line is a cable; a dashed line is a radio link.

The program

What controls ColdRoom

for (;;) {
    ev = wait_event(MINUTE_TICK | DOOR_EDGE | DELIVERY_KEY);
    if (ev == DOOR_EDGE) { log_door(reed_read()); continue; }
    if (ev == DELIVERY_KEY) { start_receiving_record(ds18b20_read(PRODUCT)); shelf_photo(BEFORE); }
    row = make_row(ds18b20_read(AIR), ds18b20_read(PRODUCT), sht45_read(), door, on_mains());
    flash_append(&row);                            // 12-month record
    run_cooler_rules(&row);                        // door, defrost, short-cycling, power loss
    if (photo_due() && door_shut() && light_on()) {
        img = camera_grab();
        if (!person_in(img)) send_zone_tasks(score_zones(img, reference));
    }
    uplink(wifi_up() ? MQTT_WIFI : LTE_M_NRF9151);  // alerts first, photos only on Wi-Fi
}

To your phone

How the data reaches ColdRoom app and contractor dashboard

iPhone, Android or browser

1. ColdRoom hub
2. Wi-Fi · MQTT over TLS
3. IEMI cloud
4. LTE-M backup (nRF9151)
5. IEMI cloud
6. Push · SMS · web
7. Manager and contractor

Key specs

Targets for production units; they may change during development.

Pricing

Target pricing. Bought separately, CoolerCheck ($199 + $12/mo), ColdChain Guard (from $199 + $49/mo) and ShelfScan (from $299 per camera + $29/mo per cooler) add up to $697 + $90/mo. Parts cost about $119 per walk-in (est.).

Indicative launch pricing in USD, excluding taxes and shipping. Final pricing is confirmed before any balance is charged.

1. 28 Oct 2026, 11:05LatestA kitchen, grocer or pharmacy needs one thing at the walk-in that keeps the temperature log, calls a propped door, a power cut or a stuck defrost before the food is lost, and checks nobody is left inside. The FDA Food Code wants a thermometer and cold holding at 5 °C (41 °F), the CDC wants a buffered data logger for vaccines, and kits cost $365 to $449 (ThermoWorks) with a gateway and a paper log.

   • Now part of ChillOne: https://iemilabs.com/products/chillone/

   See it in 3DFull research and design

2. 27 Oct 2026, 02:53Restaurant and small-grocer walk-in coolers must hold food at 5 °C or below (FDA Food Code 2022), so kitchens pay for a temperature alarm (Temp Stick, SensorPush), keep a paper log for the inspector and walk in before every order to see what is low (MarketMan and similar apps are $199–749 a month).

   • New product ColdRoom: one XIAO ESP32S3 Sense brain with a camera, one LTE-M backup modem, one backup battery and one app do the jobs of CoolerCheck, ColdChain Guard (in the walk-in) and ShelfScan (for the cooler)
   • New CAD parts: a hub (base and lid with a camera window, DELIVERY key and three lights), a wall bracket, an antenna plate with the QR record label for the kitchen side, and a door-seal pass for the power and antenna leads; CoolerCheck's air probe clip, glycol bottle holder and door magnet bracket reused; every bought part fits and each part is one solid
   • 3D view: inside a restaurant walk-in, with the hub above the closed door, wire shelves of produce and dairy, the product probe bottle on a shelf and the antenna plate outside
   • Dropped: CoolerCheck's LoRa gateway and roof CT node, ColdChain Guard's truck GPS and BLE door tag, and ShelfScan's Pi hub and battery shelf cameras
   • Product page: $299 + $29 a month per walk-in, against $697 + $90 a month for the three products bought separately; parts about $119 (est.)
   • New product page: https://iemilabs.com/products/coldroom/

   See it in 3DFull research and design

3. 27 Oct 2026, 02:53Owner decision (27 Oct 2026): merge our single-job products into multi-job devices.

   • New product page: https://iemilabs.com/products/coldroom/

   See it in 3DFull research and design

4. 27 Oct 2026, 02:53Owner decision (27 Oct 2026): merge our single-job products into multi-job devices.

   • New product page: https://iemilabs.com/products/coldroom/

   See it in 3DFull research and design

5. 27 Oct 2026, 02:53Owner decision (27 Oct 2026): merge our single-job products into multi-job devices.

   • New product page: https://iemilabs.com/products/coldroom/

   See it in 3DFull research and design