CricketOne stump board: request for quote

From: IEMI Labs, [email protected] · Date: 3 November 2026 · Reference: IEMI-CO-SB-A

We are asking for a turnkey quote: finish the design of our stump board, make it, assemble it, test it, and deliver boards that are ready to run. When a board arrives, we power it from its battery, 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, in 3D and in drawings: iemilabs.com/build/cricketone-boards.

1. The board

One rigid-flex board per cricket stump. It folds into a 31.75 mm bore in one piece, with sections from top to bottom:

Section	Type	Size	What is on it
Hall fingers (2)	flex	3 × 33 mm	one Hall switch at each tip
Head	rigid, 4 layers	22 × 24 mm	camera chip, lens holder, camera power and clock
Camera flex	flex	10 × 80 mm	2-lane MIPI CSI, power, I2C; two light wings, each 8 × 42 mm with 4 side-emitting LEDs
Brain	rigid, 8-layer HDI	28 × 93 mm	the processor, memory, storage, power, Wi-Fi/BT, sensors, security chip, sounder, microSD
Tail	flex	4 × 453 mm	battery power and gauge signals; stiffened pads for the cells’ nickel tabs
Base disc	rigid, 4 layers	Ø 28.4 mm	LiFePO4 charger, protection, gauge, tamper switch, charge pads

The outline, sections and placement of all 48 parts are fixed (KiCad 10 file, checked: 0 DRC violations). Each part’s position has been checked against our mechanical CAD (rev T). Please keep the outline and part positions. Tell us if anything must move.

2. Key parts

Ref	Part	Note
U1	Rockchip RV1126B-P	0.65 mm-pitch FCCSP; please follow Rockchip’s hardware design guide and reference design
U2	LPDDR4X, 8 Gbit ×32 (1 GB)	per Rockchip’s memory support list
U10	eMMC 5.1, 8 GB, industrial	per Rockchip’s support list; delivered empty (the processor would start from a written eMMC before the card)
U3, U4	power tree from one 3.3 V rail; buck-boost from a 2.5–3.6 V LiFePO4 cell (TPS63020-class)
U5, ANT1	AMPAK AP6256 Wi-Fi 5 / BT 5 (certified), chip antenna in a 27 × 12 mm keep-out
U20	OmniVision OV9281 global-shutter camera chip, 2-lane MIPI, frame-sync (FSIN) input wired to an RV1126B timer pin	please confirm you can source it, or propose a same-footprint module
LH1	M8 lens holder, Ø7 lens	lens to be agreed
U7	ST LSM6DSOX motion sensor
U8	Microchip ATECC608B security chip
U9	2 kbit ID EEPROM
U6, D1–D8	I2C constant-current LED driver; 8 side-emitting LEDs
H1, H2	TI DRV5032 Hall switch, X2SON
BZ1	7 × 7 mm magnetic buzzer
J1	microSD socket with a hinged, latched lid (not push-push: it must not eject on a ball hit)	fitted on every board: our software starts from the card
U12	card power switch (TPS22917-class) on SDMMC0_PWREN, 10 kΩ discharge	the processor can power-cycle a stuck card
U13	card ESD and filter array, 6 lines (TPD6F003-class), 22 Ω series on CLK, CMD, D0–D3; card detect to SDMMC0_DET
U30	TI BQ25070 LiFePO4 charger, 1 A
U31	1-cell LiFePO4 protector (about 2.5 V cut-off) + dual FET	please propose the part
U32	battery gauge with LiFePO4 support (MAX1726x-class)
SW1	Omron D2F-01 tamper switch
Cells	3 × LiFePO4 26650, 3.4 Ah (Power Sonic PSL-FP-IFR26650EC or PLB IFR26650-34D), 1S3P	soldered to the tail pads BT1–BT4 (option A in §4)
Y1, Y2, Y20	MEMS oscillators (24 MHz, 32.768 kHz, camera 24 MHz; SiTime SiT8008 / SiT1533 class)	quartz crystals are not rated for the shock of a ball hit (about 4,000 g)

The full list, with each part’s size, side and position, is stump-board-parts.csv in the pack.

3. Scope of work

1. Schematic from Rockchip’s RV1126B reference design and our block list. We review it before layout.
2. Layout in our outline and placement: the RV1126B memory and power routing, impedance-controlled MIPI and USB, and RF for the antenna. Include the stack-up proposal, 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, with X-ray inspection of the ball-grid parts. Underfill under U1, U2, U10 and U5, and flexible-termination capacitors near the board edges (the stump takes ball hits of about 4,000 g).
6. Board support package: U-Boot and a Linux device tree for this layout, built from Rockchip’s RV1126B SDK, with a real-time (PREEMPT_RT) kernel. A Rockchip SDK image must start from the microSD card. The OV9281 driver must support the full 1280 × 800 at 120 fps mode and a 1280 × 400 window at 200 fps (our tracking needs it), with the frame-sync input. We add our own software on top.
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, and the BSP source.

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 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.

Please quote both battery options:

• A: cells fitted. The three 3.4 Ah LiFePO4 cells are soldered to the tail pads BT1–BT4, protection checked, charged to storage level, and shipped as cells in equipment (UN3481). Please tell us your rules for this.
• B: cells not fitted. The tail pads come with a short, polarised battery lead and plug for our bench cells, plus one charged three-cell pack per board. Nothing else to do on our side.

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: with the eMMC empty, the board starts the Rockchip SDK image from the microSD card to a shell over the debug UART, 10 times in a row from power-off. The card power switch restarts the card. The eMMC is detected, then left empty.
4. Camera: OV9281 streams 1280 × 800 at 120 fps and a 1280 × 400 window at 200 fps over MIPI, with no lost frames over 10 minutes and a frame of a test chart saved; the frame-sync input triggers frames.
5. Wi-Fi joins a WPA2 network; Bluetooth advertises.
6. Sensors and outputs:
   • motion sensor reads, and its interrupt works;
   • security chip answers (serial read);
   • ID EEPROM reads back;
   • each of the 8 LEDs lights in turn, checked with a light sensor;
   • each Hall switch changes with a magnet;
   • the tamper switch changes;
   • the sounder sounds.
7. Battery:
   • charges from the charge pads at 3.6 V (±1 %);
   • protection cuts off at low voltage and on a short;
   • the gauge reads charge;
   • the thermistor reads.
8. Power: the draw in idle, between balls (camera at 60 fps) and in a delivery (camera at 200 fps with the AI engine running), so we can check our budget: about 0.55 W, 1.3 W and 2.8 W. Our design review needs at least 10 hours on three cells, aged and cold.
9. Heat: the processor temperature after 1 hour at full load in a 35 °C room, against our estimate.

6. Quantities and timing

Item	Quantity
Rev A boards	6 (one wicket) and 12 (two wickets): please quote both
Budget prices	for 100 and 1,000 boards
Quote wanted	by 17 November 2026
Boards wanted	February 2027 (please give your lead times for design, fabrication and assembly)

7. The design pack

Download the design pack (zip):

File	What it is
QUOTE.md	this request
stump-board.kicad_pcb	KiCad 10 board: the rigid-flex outline, sections and placement of all 48 parts (DRC 0)
stump-board.step	3D model of the board
assembly-side-A.pdf, assembly-side-B.pdf	placement drawings of both sides
placement-both-sides.csv, stump-board-parts.csv	part positions and the parts list
gerbers/	outline and fab layers (no copper yet: the layout is part of your work)
mechanical/	STL of the stump parts the board fits into (rev T), for checking fit
drawings/	the board in the stump (side view) and every part, both sides

8. Questions for you

1. Have you laid out RV1126B (or RV1126 / RK3566-class) boards before? Can you share a reference?
2. Can you build an 8-layer HDI rigid-flex board with 0.65 mm-pitch BGAs in these sizes, including the 453 mm flex tail? If not, what would you change?
3. Can you source the RV1126B-P, the LPDDR4X and the OV9281?
4. Which battery option (A or B) can you ship to the USA, and how?
5. What is your price and lead time for each step: schematic, layout, fabrication, assembly, BSP, testing?

Thank you. Please reply to [email protected].