CareOne board: request for quote

From: IEMI Labs, [email protected] · Date: 4 November 2026 · Reference: IEMI-C1-LB-A

We are asking for a turnkey quote: finish the design of our locker board, make it, assemble it, test it, and deliver boards that are ready to run. When a board arrives, we power it from a 5 V bench supply, put in our microSD card, and it starts our software. We do no setup, soldering or configuration.

All files are in the design pack (zip). The board, part by part: iemilabs.com/build/careone-boards.

1. The board

One rigid-flex board in a bedside locker’s sealed top: a 4-layer 453.8 × 435.8 mm top board flat over the service tray (ESP32-S3 module with its antenna at the right edge, security chip, ID chip, latched microSD, power lead, charger, two soldered 18650 holders with a thermistor, two NAU7802 load-cell chips with gauge-wire pads, radar rails and flash, tamper switch; notched round the two load-cell blocks), a 50 mm flex bending a 370 × 45 mm 2-layer front strip 90° up (8 call-light LEDs, sounder), a 14 mm flex bending a 28 × 34 mm radar tab 65° up (TI IWRL6432AOP), a 60 mm flex bending a 140 × 45 mm 2-layer side strip 90° up (sealed call-key switch, MEMS mic), and a 12 mm wide flex about 684 mm long down to an 80 × 20 mm 2-layer glow strip with 8 LEDs.

The outline, sections and placement of all 42 parts are fixed (KiCad 10 file, design rule check: 0 violations), each checked against our mechanical CAD. Please keep the outline and part positions, and tell us if anything must move.

2. Parts

Ref	Part	Where
U1	Espressif ESP32-S3-WROOM-1-N16R8: ESP32-S3, 16 MB flash, 8 MB PSRAM (voice notes, radar tracks), PCB antenna, FCC/CE certified; castellated, soldered, turned so the antenna end meets the right edge	top
U2	Microchip ATECC608B, UDFN-8: signs every call	top
U9	ID EEPROM 2 kbit (product, board version, serial, calibration)	top
J2	microSD socket with a hinged, latched lid (Amphenol 101-00660 class), fitted on every board: our software starts from the card (ESP32-S3 SD bus; the loader the maker flashes reads our program from it)	top
U90	microSD card power switch (TPS22917-class load switch, 3.3 V, driven by the card power-enable pin) with a 10 kΩ discharge resistor: a stuck card can be power-cycled	top
U91	microSD ESD and filter array, 6 lines (TPD6F003-class), with 22 Ω series resistors on CLK, CMD and D0–D3 and the card-detect line	top
U7	Level shifter for the LED data lines (3.3 to 5 V), call light and floor glow	top
J1	Molex Micro-Fit 3.0 single-row vertical header, 2 circuits, latched: 5 V and ground from the listed USB adapter’s lead, which comes up through a grommet in the service tray	top
U4	5 V input: polyfuse, TVS, reverse block; TI BQ24074 1S charger with power path (1 A, NTC input); TI TPS63020 3.3 V buck-boost	top
BT1	Keystone 1042 SMT holder for one 18650 cell (Samsung INR18650-35E), back cell	top
BT2	Keystone 1042 SMT holder for one 18650 cell (Samsung INR18650-35E), front cell	top
RT1	NTC thermistor 10 k, 0603, between the two cell holders, read by the BQ24074 so charging holds outside 0–45 °C	top
U5	Nuvoton NAU7802 24-bit load-cell chip for the water-jug plate’s 5 kg bar, with its four gauge-wire pads	top
U6	Nuvoton NAU7802 24-bit load-cell chip for the hand-rub plate’s 1 kg bar, with its four gauge-wire pads	top
PD1	Four solder pads for the load cell’s gauge wires (red, black, white, green), strain-relief slot beside them	top
PD2	Four solder pads for the load cell’s gauge wires, strain-relief slot beside them	top
U8	Radar rails (TI LP87745 class PMIC), 40 MHz crystal and 2 MB QSPI flash for the radar’s own program	top
SW1	Omron D2F-01, plunger down, pressed by a 1.5 mm boss on the service tray when the tray is screwed in	top
TP1	Factory pads: USB (ESP32-S3 native), serial, boot, enable, rails, current sense	top
TP2	Factory pads: 5 V in, battery, 3.3 V, charger status	top
LS1	Magnetic sounder 12 × 12 SMD over the tone holes (the call tone)	front
Q1	Sounder driver FET	front
U3	TI IWRL6432AOP 60 GHz radar, antennas in package (2 TX, 3 RX), low-power tracking: sitting up, legs over the edge, lying and turning, someone low on the floor, the carer at the bedside	tab
SW2	C&K KSC series sealed tact switch (IP67, 6.2 × 6.2), under the printed flush key cap in the Ø16.4 hole: press = help, hold = a voice note	side
MK1	Infineon IM69D130 MEMS mic, bottom port over a Ø1 hole through the strip (the voice note while the key is held)	side
GK1	Silicone sound gasket Ø5 × 6 from the strip hole to the mic port in the bed-side skin	side
D1	RGB LED with driver, 5050 (WS2812B class), behind the opal call-light skin: yellow, green, amber, red	front
D2	RGB LED with driver, 5050 (WS2812B class), behind the opal call-light skin: yellow, green, amber, red	front
D3	RGB LED with driver, 5050 (WS2812B class), behind the opal call-light skin: yellow, green, amber, red	front
D4	RGB LED with driver, 5050 (WS2812B class), behind the opal call-light skin: yellow, green, amber, red	front
D5	RGB LED with driver, 5050 (WS2812B class), behind the opal call-light skin: yellow, green, amber, red	front
D6	RGB LED with driver, 5050 (WS2812B class), behind the opal call-light skin: yellow, green, amber, red	front
D7	RGB LED with driver, 5050 (WS2812B class), behind the opal call-light skin: yellow, green, amber, red	front
D8	RGB LED with driver, 5050 (WS2812B class), behind the opal call-light skin: yellow, green, amber, red	front
D9	RGB LED with driver, 5050 (WS2812B class), amber at night, behind the bed-side panel’s opal skin	glow
D10	RGB LED with driver, 5050 (WS2812B class), amber at night, behind the bed-side panel’s opal skin	glow
D11	RGB LED with driver, 5050 (WS2812B class), amber at night, behind the bed-side panel’s opal skin	glow
D12	RGB LED with driver, 5050 (WS2812B class), amber at night, behind the bed-side panel’s opal skin	glow
D13	RGB LED with driver, 5050 (WS2812B class), amber at night, behind the bed-side panel’s opal skin	glow
D14	RGB LED with driver, 5050 (WS2812B class), amber at night, behind the bed-side panel’s opal skin	glow
D15	RGB LED with driver, 5050 (WS2812B class), amber at night, behind the bed-side panel’s opal skin	glow
D16	RGB LED with driver, 5050 (WS2812B class), amber at night, behind the bed-side panel’s opal skin	glow

Each part’s size, side and position is in careone-board-parts.csv in the pack. Ask before you substitute a part.

3. Scope of work

1. Schematic from Espressif’s ESP32-S3 hardware design guide and our block list. We review it before layout.
2. Layout in our outline and placement, and RF for every antenna keep-out. Lay the fast lines on a solid ground plane (inner layer 1, supply on inner layer 2; on a 2-layer section the whole bottom is ground under the module), with one via beside each ground and supply pad and no vias in pads unless you quote filled and capped vias (IPC-4761 type VII); no copper or vias in the antenna keep-out on any layer, none under the card socket; route the impedance lines first (antenna 50 Ω) and add an impedance test coupon. Include the stack-up proposal and DFM, and a rigid-flex drawing (bend lines, stiffeners, coverlay).
3. Fabrication of the rigid-flex board.
4. Sourcing of all parts.
5. Assembly, both sides. Conformal coating (IPC-CC-830), with the sensors, sockets, connectors and antennas masked.
6. Firmware: flash our small ESP32-S3 loader (we send it). At each start it reads our program from the microSD card, so a new card is a software update.
7. Test of every board to the acceptance list in §5, with a test report per serial number.
8. Deliverables: KiCad (or Altium) source, Gerbers, drill, pick-and-place, BOM, stack-up, test procedure and reports.

4. “Ready to run” on delivery

This is the most important part of the job:

• Every board arrives assembled, programmed and tested.
• We put our microSD card in (J2, a hinged, latched socket) and power it, and it starts. No soldering, no jumpers, no settings, no flashing.
• The ID EEPROM is written with the serial number and board revision.
• The security chip is provisioned per the steps we will send.

5. Acceptance tests (each board, with report)

1. Current-limited first power-on: no short, idle current within the agreed limit.
2. Rails: every power rail within ±3 %.
3. Boot: starts our loader and a test program from the microSD card.
4. Radios: U1 (Espressif ESP32-S3-WROOM-1-N16R8): each joins or answers a test station.
5. Sensors and outputs, each read or driven in turn: U91 (microSD ESD and filter array), U8 (Radar rails), LS1 (Magnetic sounder 12 × 12 SMD over the tone holes), U3 (TI IWRL6432AOP 60 GHz radar), SW2 (C&K KSC series sealed tact switch), MK1 (Infineon IM69D130 MEMS mic), D1–D16 (RGB LED with driver).
6. Power: the draw at idle and at full load from a 5 V bench supply, against our estimate.
7. Heat: the ESP32-S3 temperature after 1 hour at full load in a 35 °C room, against our estimate.

6. Quantities and timing

Item	Quantity
Rev A boards	5 and 20: please quote both
Budget prices	for 100 and 1,000 boards
Quote wanted	within two weeks of this request
Boards wanted	please give your lead times for design, fabrication and assembly

7. Our design review

Before we order, every board-level number is checked against its target: 8 pass, 2 fixed by the review, 10 to prove on rev A, 0 fail. The full review is on the board page and in the pack. Rev A must let us measure:

• Power cut
• Card grade
• Wi-Fi from the locker top
• Fast lines on a solid ground plane
• Board inside the product CAD, every part checked in 3D
• Every bed-bay call in the radar’s view
• Radar through the front skin
• Tamper switch against the service tray
• Call key travel
• The glow tail

8. The design pack

Download the design pack (zip): this request, the KiCad 10 board, a 3D model (STEP), side A and side B drawings (PDF), the parts list, placement, the board outline and drawing layers as Gerbers, and the design review.

Questions: [email protected]