CallNote

How it fits together

CallNote, 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 CallNote

   A handset with four keys replaces the nurse-call cord. Each press says why help is needed, and a held key records a short voice note.

2. 02Brain

   Seeed XIAO ESP32S3 Sense

   The brain: it runs the CallNote handset firmware program

3. 

   03

   Four reason keys

   Each key closes the call loop and tells the chip why

   Seeed XIAO ESP32S3 Sense · GPIO pins (one per key) · Key presses and hold time

4. 

   04

   1.54 in e-paper screen

   Shows Sent or Help is coming with no power

   Seeed XIAO ESP32S3 Sense · SPI · Screen image

5. 

   05

   Accelerometer

   Spots a fall to the floor and wakes the handset

   Seeed XIAO ESP32S3 Sense · I²C and interrupt pin · Motion, free-fall signal

6. 06

   Vibration motor

   Buzzes in the hand when a carer accepts

   Seeed XIAO ESP32S3 Sense · GPIO pin · Buzz on and off

7. 07

   1800 mAh LiPo cell

   Powers the handset for months between charges

   Seeed XIAO ESP32S3 Sense · Board battery pads, USB-C charge · Power

8. 

   08

   Cord and plug

   Closes the existing wall-jack call so the dome light still works

   Seeed XIAO ESP32S3 Sense · 2-core cord to wall jack · Call loop contact

9. 09

   All connected

   7 key parts, one program, and your phone

How the parts connect

CallNote, 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 CallNote

while (true) {
  deep_sleep_until(KEY_PRESS | FREE_FALL);   // LIS3DH interrupt also wakes
  if (woke_by == FREE_FALL) {
    if (still_for(30 /*s*/)) mqtt.publish("drop", fall_json());
    continue;
  }
  reason = read_key();                       // HELP, TOILET, PAIN, DRINK
  clip = key_held_ms() > 800 ? mic.record_pdm(10, 16000) : none;
  wifi.join();
  mqtt.publish("call", call_json(reason, clip, battery()));
  epaper.show("Sent");
  if (wait_for_cmd("accepted", 30 * 60)) { motor.buzz(2); epaper.show("Help is coming"); }
}

To your phone

How the data reaches CallNote carer app

Carer's phone or browser

1. Handset
2. Wi-Fi · MQTT over TLS
3. Site hub (Pi 5)
4. Web push · local web app
5. Carer's phone

Key specs

Targets for production units; they may change during development.

Pricing

Target pricing. Edge Hub $299 per site, or shared with other IEMI products. Parts cost is about $62 per handset at qty 1 and about $30 at qty 1,000 (est.).

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

1. 28 Oct 2026, 11:40LatestA care home or ward needs one thing at each bed that calls a resident getting up before they stand, someone on the floor and what a call is for, and fills the turn, fluid and hand-rub records, without a camera in a private room. CQC asks for the least intrusive option, a bed-exit signal is a Class I exempt bed-patient monitor (21 CFR 880.2400), and homes pay about $240 a room + $19.99 a month for a wall radar (Vayyar) on top of mats and call bells.

   • Now part of CareOne: https://iemilabs.com/products/careone/

   See it in 3DFull research and design

2. 27 Oct 2026, 03:45Owner decision (27 Oct 2026): merge our single-job products into multi-job devices.

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

   See it in 3DFull research and design

3. 25 Oct 2026, 11:26A call light says someone needs something, not what (toileting is the top reason) → 4 reason keys route TOILET and DRINK to aides and PAIN to the nurse, saving 1.0-2.2 staff-hours a day per 30 beds (CAD route report, est.)

   • New design: 4 printed parts in code CAD, bought parts fit-checked
   • Market research, hardware list and use case written up
   • Design page and kit render published
   • Product page added

   See it in 3DFull research and design