PaceRoll

How it fits together

PaceRoll, 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 PaceRoll

   Magnets on a rollator wheel and a pod under the grip measure walking distance and gait speed, check the brakes, and alert the family.

2. 02Brain

   XIAO ESP32-C3 (HandlePod)

   The brain: it runs the handlepod firmware program

3. 03

   Wheel Hall sensor

   Counts 8 wheel magnets to measure distance walked

   XIAO ESP32-C3 (HandlePod) · 3-core cable to GPIO · Wheel pulses

4. 04

   Brake Hall sensor

   Senses the brake-lever magnet to tell if brakes are parked

   XIAO ESP32-C3 (HandlePod) · GPIO pin · Brake parked or free

5. 

   05

   Motion sensor (IMU)

   Detects turns, sit-downs and a fallen walker

   XIAO ESP32-C3 (HandlePod) · I²C (4 wires) · Acceleration and yaw rate

6. 

   06

   E-paper display

   Shows today's distance and park reminders

   XIAO ESP32-C3 (HandlePod) · SPI · Screen image

7. 07

   NightPath leg lamp

   Lights the floor in amber for night toilet trips

   XIAO ESP32-C3 (HandlePod) · Cable via I²C expander · LED power on/off

8. 08

   BedTag bed sensor

   Sees when someone leaves the bed at night

   XIAO ESP32-C3 · ESP-NOW radio · Bed exit events

9. 09

   18650 battery

   Runs the pod for about 190 days per charge

   XIAO ESP32-C3 (HandlePod) · Power lead via XIAO charger · 3.7 V power

10. 10

    All connected

    8 key parts, one program, and your phone

The idea

The rollator they already use, made smart: walking speed every day, a brakes reminder and a walker-down alert

How the parts connect

PaceRoll, 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 PaceRoll

for (;;) {
    imu_wait_for_motion();                     // deep sleep until LSM6DSOX wakes the C3
    while (state == MOVING) {
        pulse = wheel_pulse_ms();              // DRV5023, 1 ms stamps
        yaw   = imu_yaw_rate();                // 52 Hz
        track_straight_segment(pulse, yaw);    // >= 3 m, |yaw| < 10 deg/s
        if (sit_down_signature() && !brake_parked())
            chirp(3);                          // "PARK BRAKES"
        if (tilt_deg() > 45 && still_for(5000))
            send_alert("down");
    }
    if (day_done()) mqtt_publish("pr/<id>/day", day_json());
}

To your phone

How the data reaches PaceRoll family app

Family phone, plus a therapist dashboard

1. HandlePod
2. Home Wi-Fi · MQTT over TLS
3. IEMI cloud
4. App, SMS and web dashboard
5. Family phone

Key specs

Targets for production units; they may change during development.

Pricing

Target pricing. $129 kit, $159 with NightPath. Parts cost about $55 per kit plus about $35 for NightPath at qty 1 (est.).

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

1. 29 Oct 2026, 09:40LatestPhysios measure walking speed, the 'sixth vital sign', a few times per episode with a stopwatch, and families cannot see walking at home; brakes depend on memory, and the activity clip on sale ($199 plus a plan) counts movement but not distance, speed or brakes (PaceRoll DESIGN.md market check).

   • Drawn idea plan (idea.json): a small home from above with the bedroom, hallway, bathroom, living room chair and kitchen table, and the rollator's daily route between them; pins for the rollator with its handle pod, the brakes at the chair, the bed tag on the bed leg, the night walk to the bathroom and the physio's weekly view
   • The product picture is now this drawn plan instead of the plain fallback card; drawn from the design notes, not the CAD
   • What the plan keeps from the market work: walking speed is only taken on straight walks, and walker-down is an alert, not fall detection
   • Next: more drawn plans for catalogue products that still show the fallback card (parksense-ai, pesttrap-ai), then close-out C5 (buyer review prep for sports) from 12:00

   See it in 3DFull research and design

2. 27 Oct 2026, 08:30Families looking after an older parent at a distance often face three worries at once: were the pills taken, how long will the backup oxygen last in a power cut, and is the parent still walking safely, especially on night toilet trips. Today that means a pill dispenser subscription (Hero $29.99-44.99 a month, herohealth.com), a medical alert ($25-29 a month, AARP 2026) and nothing for oxygen or walking; our own three products for it cost $447 and $14 a month with three apps.

   • Combined into ParentHome (https://iemilabs.com/products/parenthome/); PaceRoll itself is unchanged

   See it in 3DFull research and design

3. 26 Oct 2026, 00:49Families with an older parent at home fear the night walk to the toilet most: in a study of people over 60, a third of falls were toilet trips, at least 44% of them at night, and in 80% of those the person was walking without their usual aid (Rose et al., Australasian Journal on Ageing, 2019).

   • New CAD part: NightPath leg lamp, an amber floor light that clips to a front leg and is wired to the HandlePod
   • New CAD parts: BedTag case and lid for the bed leg, holding a laser distance sensor, an amber glow, a soft chime and 2 AA cells; 22 bought-part checks pass, lid on case 0 mm³
   • HandlePod case: second cable hole for the lamp; new CAD reports for the sensor's view along the bed, the light on the floor and battery life
   • BOM: NightPath about $35 at qty 1; kit with NightPath about $90 (est.)
   • Design doc: dated section with 6 sources and 5 new tests; product page summary, highlights, use cases, specs, price and FAQs updated

   See it in 3DFull research and design

4. 25 Oct 2026, 09:26Clinical smart rollators cost 3,000-9,000 euros and are closed systems → a $55 BOM clip-on kit (est.) on the user's own rollator, any brand with a fixed rear wheel

   • 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