Our own circuit boards, in the backboard

Boards we design for the smart backboard, with every chip soldered on them: the RV1126B processor and its memory, the 8 MP top camera chip, two 5 MP corner camera chips, the rim motion chip, the call lights, the shot clock digits, the Wi-Fi module, the security chip and the mains supply. One rigid-flex piece lies in the top rail with the top camera at its window; a corner board stands in each side rail, a rim board sits in the ring box, light sections line the frame’s slots and the clock box holds the digit boards and the power board. The same set goes in both backboards. No bought modules, LED panels, ribbons or adapters.

Stage 1 of 6 done: shape and placementNot yet ready to manufactureUpdated 4 November 2026 · rev A-0

Design files Design review Quote pack Who can make it Our board platform

The board in 3D

Every part at its real size, in its real place. Turn it, zoom in, switch between the boards in the backboard and laid flat, and click any part to see what it is. The chip bodies are simple blocks until each part's own 3D model is added.

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Where everything is in the backboard

Top cameratop rail, middle

A bare Sony IMX415 8 MP camera chip on a small head off the main board, under an M8 lens whose front sits just inside the front face, tilted 51° down: the ball in and through the ring, the ring’s front edge, goaltending, the free-throw line and the shooter’s feet on the arc.

Corner camerasside rails, 700 mm up

In each side rail a corner board with an ESP32-S3 and a bare OmniVision OV5640 5 MP chip on a head, looking out of the side face 30° to the court and 30° down: the shooter’s feet in the corner and at the wing for three points. Frames go to the main board only round a shot.

Processor, radio and securitytop rail

The RV1126B with its memory on the main board, a heat block into the aluminium top rail, the Wi-Fi module with its antenna behind a radio window in the back face, the security chip that signs every call, the latched microSD card with our software, and a tamper sensor held by a magnet in the service cover.

Rim sensorring box

A small board on the ring plate with a motion chip that feels every rim and net hit through the steel: the shot clock reset on a touch of the ring, a lodged ball and a player hanging on the ring.

Call lights and shot clockframe and clock box

Twenty-nine light sections over the frame’s slots: red all round at the end of a period, yellow along the top at the shot clock signal. In the clock box, two digit boards show the seconds, and tenths under 5 s, on both faces.

Mains powerclock box

A power board between the digit boards takes the gym’s shot-clock feed into a push-in terminal, through a fuse to a soldered Mean Well supply, with a milled slot between the mains and 5 V sides. Only 5 V comes down to the backboard.

The backboard boards laid flat, both sides, every part at its real size

Laid flat: the main board with the top camera head; the corner board with its head; the rim board; one light section; one digit board; the power board. Tap the drawing to open it full size.

Design review: checked before we order

Every board-level number CourtOne's jobs depend on, checked against its target with the source of each number, using the rules every one of our boards shares (products/_shared/board-rules.mjs). Fixed means a lesson changed this board; to prove means it passes on paper and is measured on rev A before boards are ordered.

No check fails24 pass · 4 fixed by the review · 13 to prove before we order · 0 failDesign review of 4 November 2026

Area	Check	Our board	Target	Status
Camera	Top camera: a shoe (0.1 m) on the arc 30° off centre at 8.15 m M8 lens, 80° × 50.6°, tilted 51° down: about 48 px per degree across 3840 px. Three points from the top of the arc, made baskets, the shot clock reset on the ring and goaltending all come from this camera; the shooter's foot on the arc is the smallest thing at the farthest place. The ball at the ring is 1 m away and 24 cm across, so 30 fps (23 cm of ball travel at 7 m/s) is enough to see it pass through the ring.	33.7 px	≥ 20 px	passes
Camera	Top camera: smear at 11 km/h, 2 ms exposure A rolling shutter skews a fast target: check the readout time.	6 mm	≤ 1/3 of the shoe (33 mm)	passes
Camera	Top camera: frame rate the calls need A standard mode of the IMX415.	30 fps at 3840 × 2160	chip: 30 fps at 3840 × 2160	passes
Camera	Top camera: data rate vs its 4-lane link 30 % spare on the link.	2.49 Gbps (10-bit)	≤ 80 % of 3.564 Gbps	passes
Camera	Right corner camera: a shoe (0.1 m) at the wing, 45° on the arc at 7.39 m M8 lens, 60° × 46.8°, rows cropped to the floor band: about 43.2 px per degree across 2592 px. Feet on or behind the three-point line in the corner and at the wing. The sensor crops to the 800 rows where the floor is, and the ESP32-S3 keeps the last 2 s of JPEG frames; when the top camera sees a shot leave the hand, the main board asks for the four frames round the release (about 0.5 MB, 1 s over the link), before the ball reaches the ring.	33.5 px	≥ 20 px	passes
Camera	Right corner camera: smear at 7 km/h, 4 ms exposure A rolling shutter skews a fast target: check the readout time.	8 mm	≤ 1/3 of the shoe (33 mm)	passes
Camera	Right corner camera: frame rate the calls need A standard mode of the OV5640.	10 fps at 2592 × 800	chip: 15 fps at 2592 × 1944, 30 fps at 1920 × 1080, 60 fps at 1280 × 720	passes
Camera	Right corner camera: data rate vs its 1-lane link 57 % spare on the link.	0.17 Gbps (8-bit)	≤ 80 % of 0.384 Gbps	passes
Camera	Left corner camera: a shoe (0.1 m) at the wing, 45° on the arc at 7.39 m M8 lens, 60° × 46.8°, rows cropped to the floor band: about 43.2 px per degree across 2592 px. Feet on or behind the three-point line in the corner and at the wing. The sensor crops to the 800 rows where the floor is, and the ESP32-S3 keeps the last 2 s of JPEG frames; when the top camera sees a shot leave the hand, the main board asks for the four frames round the release (about 0.5 MB, 1 s over the link), before the ball reaches the ring.	33.5 px	≥ 20 px	passes
Camera	Left corner camera: smear at 7 km/h, 4 ms exposure A rolling shutter skews a fast target: check the readout time.	8 mm	≤ 1/3 of the shoe (33 mm)	passes
Camera	Left corner camera: frame rate the calls need A standard mode of the OV5640.	10 fps at 2592 × 800	chip: 15 fps at 2592 × 1944, 30 fps at 1920 × 1080, 60 fps at 1280 × 720	passes
Camera	Left corner camera: data rate vs its 1-lane link 57 % spare on the link.	0.17 Gbps (8-bit)	≤ 80 % of 0.384 Gbps	passes
Camera	Image processor load, all cameras 3 cameras into one image processor.	290 Mpx/s	≤ 360 Mpx/s (RV1126B ISP)	passes
Camera	Cameras in step for timed calls A three-point call joins the shot release seen by the top camera to the feet seen by a corner camera; both sides of the court use the same pulse. A real-time (PREEMPT_RT) kernel is asked for in the quote (lesson: sync).	the corner boards timestamp each frame on a frame-sync pair from the main board, through the corner lead	the corner frames and the top camera on one clock	passes
Camera	AI engine time per frame The ball model runs on a crop round the ring and the net; the arc and the corner frames share the engine. Measured on the dev kit.	3 TOPS for the top camera and the corner frames	ball and ring model at 30 fps on a crop round the ring; person and foot model at 10 fps on the arc and on the corner frames	to prove on the dev kit
Power	Supply About 12 W in play (RV1126B board 2.7 W, two corner boards 1.6 W, rim board 0.3 W, both clock faces showing red digits 7.2 W) and 34.5 W at the end of a period, when the red rows run all round at the 0.9 A chain cap with the yellow row on (22.5 W, est.): 69 % of the supply.	the gym's shot-clock mains feed into a push-in terminal on the power board in the clock box, a PCB-mount Mean Well IRM-60-5 (5 V 10 A, 50 W)	≤ 70 % of the supply (35 W)	passes
Power	Power cut The scorer's table keeps the official game clock; cutting the shot-clock feed mid-play is part of the rev A tests.	no cells: a power cut stops the board; every call is written to eMMC as it happens and signed	no lost call in a power cut	to prove on the dev kit
Heat	RV1126B temperature, a full gym in summer, 32 °C at the top of the backboard The top rail sits 3.9 m up, where the gym is warmest, out of the sun; counted at 36 °C on the aluminium. 2.2 W through a copper heat block and gap pad from the processor to the top rail's top wall (4 K/W, est.).	45 °C	≤ 85 °C (rated)	passes
Heat	Top camera chip away from the processor A warm chip adds noise in a dim gym.	45 mm from the RV1126B	≥ 30 mm	passes
Heat	Mains supply in the closed clock box The clock box is closed aluminium; the module's temperature in the box is logged on rev A.	IRM-60-5 at about 12 W in play (24 % load) and 35 W for 3 s at a period end	inside the module's rating at 50 °C in the box, no derating	to prove on the dev kit
Shock	Shock and vibration Balls hitting the board and the ring all game, dunks and players hanging on the breakaway ring, the backstop swung up for storage (est.). The rim board feels the ring through the plate; the other boards sit in the frame. MEMS clocks are fitted anyway and every card socket is latched.	200 g (est.)	standard parts	passes
Software	Starts our software from the microSD card, no setup Owner requirement: power it from its own supply and our software runs from the card. Every board starts from its own card: the main board loads Linux and our program (the eMMC holds no system copy (it ships empty, so the card always starts first: Rockchip tries the eMMC before the card); the quote asks for U-Boot and a device tree from Rockchip's RV1126B SDK); the maker flashes our small loader into the corner and rim boards' ESP32-S3, which start our program from their cards. Updates are signed and never run during a game.	microSD socket with a hinged, latched lid (Amphenol 101-00660 class), fitted on every board: our software starts from the card; microSD socket with a hinged, latched lid (Amphenol 101-00660 class): the ESP32-S3 loads our program from the card; microSD socket with a hinged, latched lid (Amphenol 101-00660 class): the ESP32-S3 loads our program from the card	card socket fitted on every board, latched	passes
Software	Card power switch and protection A card that hangs must be restarted by cutting its power, not the whole board; the card slot is the one place a person touches the electronics (lesson: sdstart). Change: U90, U92, U94, U91, U93, U95 added (4 Nov 2026, CricketOne card-start review).	3 power switches and 3 ESD arrays for 3 card sockets	every socket: switched card supply, ESD on all 6 lines	fixed by the review
Software	The card wins the start Rockchip's start order is SPI flash, eMMC, card, USB: a written eMMC starts before the card. Proved on the dev kit: power on with a card in and the eMMC empty (lesson: sdstart). Change: eMMC ships empty and the loader reads the card first (4 Nov 2026; it used to say the eMMC kept a copy, which would have started instead of the card).	eMMC shipped empty; our loader reads the card first	the processor starts from the card every time	fixed by the review
Software	Card grade Consumer cards wear out and fail hot; the image is read-only with a separate data partition. Proved: 1,000 power cuts during writes on rev A (lesson: sdstart).	industrial pSLC microSD (Kingston Industrial or Swissbit S-56u), −40 to 85 °C	rated for the heat, cold and writes	to prove on the dev kit
Software	Clip buffer for an unsure call The rest of the memory holds Linux, the program and the AI model (lesson: clip).	3.3 s of 8-bit 30 fps video in 40 % of the 2 GB memory	≥ 3 s	passes
Radio	Wi-Fi/BT module clock The AP6256 runs from its own 37.4 MHz reference clock; a wrong or missing clock means no Wi-Fi or Bluetooth at all (lesson: wificlock).	37.4 MHz MEMS oscillator (Y2)	37.4 MHz next to the AP6256	passes
Radio	Wi-Fi and BT from inside the aluminium frame The frame is a closed aluminium tube; the bench Pi Zero 2 W had no opening at all. The window faces the gym behind the board; the range to the scorer's table and the other end is measured on rev A. Antenna outside the metal: the Ø20 PC radio window in the top rail's back face (rev T) (lesson: enclosure). Measured on rev A (lesson: antenna).	AP6256 module, its chip antenna at the main board's back edge, 2 mm behind the Ø20 radio window in the top rail's back face	certified module; the scorer's tablet at the side of the court and the other backboard 26 m away	to prove on the dev kit
Layout	Fast lines on a solid ground plane The layout rules go to the maker in the quote; the routed board's design rule check (0 copper errors, every keep-out kept) and the maker's impedance coupon prove them (lesson: planes).	RV1126B memory; 5 camera MIPI links (100 Ω pairs); USB (90 Ω); antenna feed (50 Ω, keep-out on every layer); card lines (length-matched, no vias under the socket)	ground on inner layer 1, supply on inner layer 2, no vias in pads, impedance lines routed first	to prove on the dev kit
Moisture	Conformal coating Gyms are cleaned and mopped, condense when a cold gym warms up in winter, and the clock box carries mains: all boards get the same coat. Asked for in the quote (lesson: moisture).	coated	coated, sensors, sockets and antennas masked	passes
Fit	Board inside the product CAD, every part checked in 3D The board is checked on its own; the rev T CAD run places it in the product and checks every part in 3D (lesson: fit3d).	not yet in the product CAD	nothing touches	to prove on the dev kit
Camera	Every call in a camera's view, from where each lens sits The ball in and through the ring, the ring's front edge, goaltending above the ring, the shooter's feet at the top of the arc and 30° off centre and the free-throw line from the top camera; the wing and both corner spots from the corner cameras (the rev O inView targets in cad/courtone-cad.mjs).	top camera worst 25.8° across, 22.7° up-down; corner cameras worst 20.2° / 4.5°	inside 80 × 50.6° and 60 × 46.8°	passes
Camera	Top camera window (lesson: window) The rev O Ø16 disc was never checked against the calls: the net is 74° below level, so a ray from the lens leaves the face far below the lens. An M8 lens (rim Ø8) with its front 0.5 mm inside the face, low in the rail, and a slot down to 1.5 mm above the rail's bottom edge passes every call with 1 mm to spare; the head still fits under the top wall. Change: CAD rev T: top camera window Ø16 → 18 × 39 slot, z 1,018.5 to 1,057.5; M12 → M8 lens (4 Nov 2026).	the ball through the net is 77° from the front face with the 3° margin; the view uses -6.7 to 6.7 across and -28.3 to 8.2 mm up-down of the window centre	the rev T window, 18 × 39 mm, inside the top rail's front face	fixed by the review
Camera	Corner camera windows (lesson: window) In rev O the corner cameras looked through Ø12 windows in the front face, turned 55° out: the corner 0.6 m in front of the board is 84° from the front face, so no window in that face could pass it. The side face looks 30° away from the corner calls instead, and the steepest call is 61° from it. Change: CAD rev T: corner windows moved from the front face to the side faces, 24 × 22 at y 22, z 700 (4 Nov 2026).	in each side rail's outer face, 24 × 22 mm; steepest line of sight 61° from the face; margin 0.3 mm	every corner call through the window, ≤ 70° from the face	fixed by the review
Fit	Camera heads in 3D Each head is posed on its camera's axis and every corner checked against the rail walls and its board (lesson: fit3d); the printed brackets that hold the heads go in the rev T CAD with the boards.	top head 0.3 mm behind the wall, barrel 5.7 mm, hinge 29.2 mm; corner heads 0.3 mm, barrel 6 mm, hinge 26 mm	holders ≥ 0.3 mm off the wall, heads inside the rail, hinges within their flex	to prove on the dev kit
Camera	Corner frames over the wire The corner boards do not stream: they keep 2 s in PSRAM and send only the release frames, so the link stays a simple RS-485 pair. The UART rate and the call time are measured on the dev kit.	4 frames of a 2592 × 800 JPEG crop round each shot release, about 0.5 MB, about 1 s at 4 Mbps	the three-point call before the ball reaches the ring (about 1 s)	to prove on the dev kit
Light	Call lights round the frame The bench used NeoPixel strips; our sections sit where the strips were, in five chains with the brightness capped at 0.9 A a chain. Their brightness from the far end of the court is checked on rev A.	29 light sections of 14 RGB LEDs (406 per backboard) over the 12 mm slots: red all round, yellow along the top	FIBA 1.1.6 and 1.1.7: red at the end of a period, yellow at the shot clock signal, seen from the court; RGB call colours only in club play	to prove on the dev kit
Light	Shot clock digits The bench used two bought 64 × 32 LED panels on ribbons; our digit boards carry only the LEDs the digits need, on a latched lead from the power board. Readability across the court is checked on rev A.	two digit boards, 2 digits of 130 mm and a point in 100 red LEDs each, 4 mm behind the windows	FIBA 5.6: seen from the court and the scorer's table; seconds and tenths under 5 s	to prove on the dev kit
Power	Mains on the power board The bench used an enclosed LRS-50-5; on our power board a PCB-mount module is soldered with a slot under its input. The creepage is measured from the routed board, and UL 62368-1 is still to be done.	push-in 3-pole terminal, 2 A slow-blow fuse and varistor, PCB-mount IRM-60-5 (Class II), 2 mm milled slot and 6 mm keep-out between the mains and 5 V sides; the feed in through a gland in the box floor (rev T)	creepage and clearance per IEC 62368-1 (est. 6 mm reinforced at 250 V); the gym's electrician wires the shot-clock feed	to prove on the dev kit
Fit	Leads along the frame Every lead is latched and runs inside the frame tube; the rim lead leaves the ring box top and enters at the bottom rail's back face.	clock box to the main board, 5 V: 0.6 m of 18 AWG, 0.08 V drop at 6.5 A; main board to each corner board: 1.16 m of 24 AWG, 0.07 V drop at 0.35 A; main board to the rim board: 2.05 m of 24 AWG, 0.05 V drop at 0.15 A; main board to the farthest light chain (bottom), 5 V and data: 1 m of 22 AWG, 0.1 V drop at 0.9 A	clock lead ≤ 0.15 V; corner and rim ≤ 0.25 V; light chains ≤ 0.3 V	passes
Security	Service cover tamper sensor The bench used a plunger switch; the Hall switch needs nothing to press. The switch point is measured on rev A.	DRV5032 Hall switch on the main board, a Ø10 × 5 magnet on a printed boss under the service cover 13 mm away (about 22 mT, est.)	cover opened = logged and signed	to prove on the dev kit

Before we order the first boards, we prove these on the RV1126B development kit or in the rev A tests:

AI engine time per frame
Power cut
Mains supply in the closed clock box
Card grade
Wi-Fi and BT from inside the aluminium frame
Fast lines on a solid ground plane
Board inside the product CAD, every part checked in 3D
Camera heads in 3D
Corner frames over the wire
Call lights round the frame
Shot clock digits
Mains on the power board
Service cover tamper sensor

Where the design stands

1Shape and placementdone
Main board with the top camera head, two corner boards with their heads, the rim board, the light sections, the digit boards and the power board in the backboard’s shape, all 182 parts placed at their real size, every call checked from where each lens sits, and KiCad design rule check (0 violations).
2Schematicnext
Every wire between the chips, from the V1, S1 and C1 circuits.
3Footprintsnext
The exact solder pads under each chip.
4Routinglater
Copper tracks on all layers and the flexes, with the mains spacing on the power board.
5Files for the makerlater
Gerbers with copper, drill, mask, paste, the rigid-flex drawings, the lead drawings and the assembly parts list. These go to the board maker.
6Rev A boardsMar 2027
Made, assembled and tested on our fixture, then on one court.

Design files (rev A-0)

These are the stage 1 files: the board's shape and where every part goes. A board maker needs the stage 5 files to build it.

All files (zip)Everything below in one download, with the quote and review KiCad boardcourtone-board.kicad_pcb: open with KiCad 10 (free)3D model (STEP)The bare boards for mechanical CAD Side A drawing (PDF)Up in the top rail, out to the side faces and the clock windows Side B drawing (PDF)Down to the light rows and in to the rails Parts and placement (CSV)Every part, its size, side and position

Who can make it

Each backboard set is two rigid-flex designs (the 8-layer main board with its camera head, and the 4-layer corner board with its head, twice), a rim board, 29 light sections, two digit boards and a power board, with the leads made to length; a court takes two sets. It needs a maker who builds rigid-flex boards and fine-pitch ball-grid chips, and who can test a mains board. We plan three quotes once the stage 5 files are ready: two from China for price, and one from the US for speed.

Maker	Where	Rigid-flex	HDI / layers	Assembly	Fit for us
PCBWayfirst quote	Shenzhen, China	yes, 6 to 16 layers	HDI up to 32 layers, 0.35 mm BGA pitch	yes, turnkey, incl. BGA and X-ray	Best fit for rev A: the rigid-flex board and its assembly in one order
NextPCBsecond quote	Shenzhen, China	yes	HDI, 6 to 32 layers	yes (PCBA)	Second quote, to compare price and lead time
ALLPCB	China (a network of partner factories)	yes, through partner factories	1 to 30 layers	yes	Third quote; check which factory builds it
JLCPCB	Shenzhen, China	no (flex only: 1, 2 and 4 layers, up to 490 mm)	HDI added Sep 2026	yes, incl. BGA	Not for the one-piece board today. Good for the test fixture, simple boards, and the fallback of separate rigid boards joined by soldered flex
Sierra Circuits (ProtoExpress)US quote	Sunnyvale, California, USA	yes	yes	yes, in-house, incl. BGA; turnkey in about 5 days	US option: fastest turn and engineering help, at a higher price
Cirexx	Santa Clara, California, USA	yes	yes	yes (turnkey or consigned)	Second US option
Advanced Circuits	Aurora, Colorado, USA	yes	check	yes	US quick-turn; check its rigid-flex assembly
Epec	New Bedford, Massachusetts, USA	yes	check	yes; also builds battery packs	US option that can also make a certified LiFePO4 pack

From each maker's own capability pages, checked 3 November 2026. Limits change, so each quote confirms them for our exact stack-up.

Full design notes

All 182 parts, what is on each board, every connection, heat, power, the factory test, cost and timeline.

CourtOne: circuit boards of our own

What changed (4 Nov 2026). The rev A bench backboard is built from bought boards joined by leads and ribbons: a Raspberry Pi Zero 2 W with an RGB Matrix Bonnet and the Raspberry Pi AI Camera in the top rail, two Seeed XIAO ESP32-S3 Sense corner cameras, a XIAO nRF52840 Sense in the ring box, NeoPixel strips round the frame, two bought 64 × 32 LED panels on ribbons and an enclosed Mean Well LRS-50-5 in the clock box. CourtOne now gets boards of our own, like CricketOne, on our board platform. The same set goes in both backboards; the home board’s main board is the brain and keeps the signed call log.

The chips: the V1 core (Rockchip RV1126B, 2 GB LPDDR4X, 32 GB eMMC, AMPAK AP6256 Wi-Fi/BT) with a bare Sony IMX415 8 MP top camera chip (C1); in each side rail the S1 core (ESP32-S3-WROOM-1 with 8 MB PSRAM) with a bare OmniVision OV5640 5 MP corner camera chip; an ESP32-S3-MINI-1 with the ST ISM330DHCX motion chip on the rim board; 406 RGB call-light LEDs on 29 light sections; 200 red LEDs on the two digit boards; a PCB-mount Mean Well IRM-60-5.
The shape: in the top rail, one rigid-flex piece: an 8-layer main board (340 × 32 mm) flat in the rail with a 12 × 12 mm top camera head on a 40 mm flex, tilted 51° down at the ring, the key and the arc. In each side rail a 4-layer corner board (48 × 120 mm) standing at 540 to 660 mm with a 14 × 14 mm corner head on a 30 mm flex. A 4-layer rim board (50 × 40 mm) on the plate-side wall of the ring box. Twenty-nine 2-layer light sections (240 × 14 mm) over the frame’s light slots. In the clock box, two 4-layer digit boards (320 × 160 mm) behind the windows and a 2-layer power board (150 × 120 mm) standing between them.
The top camera window (fixed): the rev O Ø16 disc was never checked against the calls. The ball through the net is 74° below level, so its line of sight leaves the front face far below the lens. With an M8 lens low in the rail, its front 0.5 mm inside the face, the window becomes an 18 × 39 slot from 1,018.5 to 1,057.5 mm and passes every call with 1 mm to spare (rev T CAD, the same day).
The corner windows move to the side faces (fixed): rev O put the corner cameras behind Ø12 windows in the front face, turned 55° out; the corner 0.6 m in front of the board is 84° from that face, so no window there could pass it. In each side rail’s outer face the steepest corner call is 61° from the face (24 × 22 windows, rev T CAD).
Radio out of the aluminium (fixed): the frame is a closed aluminium tube, so the Wi-Fi antenna sits at the main board’s back edge behind a new Ø20 radio window in the top rail’s back face (lesson: enclosure).
Made from the shared rules: MEMS clocks, the latched microSD card with our software on every board, conformal coating, the antenna checked on rev A, the camera chip 30 mm or more from the processor, each lens chosen from the calls and its front just inside the face (lesson: window).

The bench backboards stay the test rig until the boards arrive.

1. The shape: one set per backboard

Piece	Size	Layers	Where	What
Main board	340 × 32 mm, 1.6 mm	8	flat in the top rail, y 24 to 56, side A up, 10 mm over the light rows	the V1 core, Wi-Fi/BT, card, security, tamper, call tone, links, light drivers, leads
Top camera head	12 × 12 mm, 0.8 mm, on a 40 mm flex	8	off the main board’s front edge at x 0, tilted 51° down	IMX415 and M8 lens holder, lens front 0.5 mm inside the front face
Corner board (2)	48 × 120 mm, 1.6 mm	4	standing in each side rail at 540 to 660 mm, side A out (the left one turned round)	ESP32-S3, security and ID chips, links, card, lead
Corner camera head (2)	14 × 14 mm, 0.8 mm, on a 30 mm flex	4	turned 30° from the side face to the court and 30° down	OV5640 and M8 lens holder, lens front 0.5 mm inside the side face
Rim board	50 × 40 mm, 1.6 mm	4	on stand-offs on the plate-side wall of the ring box	ESP32-S3-MINI-1, ISM330DHCX, link, card, lead
Light section (29)	240 × 14 mm, 0.8 mm	2	over the 12 mm slots: 7 red and 7 yellow in the top rail, 7 in the bottom rail, 4 in each side rail	14 RGB LEDs, chain in and out
Digit board (2)	320 × 160 mm, 1.6 mm	4	4 mm behind each clock window (the back one turned round)	2 digits and a point in 100 red LEDs
Power board	150 × 120 mm, 1.6 mm	2	standing in the clock box between the digit boards	mains terminal, fuse, varistor, IRM-60-5, creepage slot, three leads

Leads: the clock lead (clock box to the main board, 5 V on two pins each way and the digit data, about 0.6 m of 18 AWG, Molex Micro-Fit 3.0 6-circuit latched, through the Ø20 hole in the back face); a corner lead to each corner board (about 1.2 m, 6-circuit: 5 V, GND, RS-485 and the frame-sync pair); the rim lead (about 2.1 m, 4-circuit, out of the ring box top and in at the bottom rail); five light chains on JST GH 3-pin latched leads (5 V, GND, data); the two digit leads from the power board.

2. What is on the boards

Main board, side A (up): RV1126B (U1) with a 16 × 16 copper heat block to the top rail’s top wall (HB1), LPDDR4X (U10), eMMC (U5), RK806 class power (U3), 24 MHz MEMS oscillator (Y1), the AP6256 Wi-Fi/BT module (U6) and its 37.4 MHz MEMS oscillator (Y2) with the chip antenna (AE1) at the back edge facing the radio window, ATECC608B (U2) and ID chip (U9, which also says home or away), the latched microSD (J1) under the service cover, the DRV5032 cover tamper switch (U7), the SMD piezo (BZ1) under a printed sound tube (GK1) to the tone holes, the IMX415 supplies (U21) and a keep-out under the head’s flex (TKO).

Main board, side B (down): the decoupling field (C1), three THVD1450 RS-485 transceivers (U14 to the corner boards with the frame sync, U15 to the rim board), two SN74AHCT125 line drivers for the five light chains and the clock digits (U36), the eFuse (U42), the latched clock lead (J2), corner leads (J3, J4) and rim lead (J5), the five light headers (J6 to J10), the antenna keep-out (ANT1) and the factory pads (TP1).

Top camera head: the IMX415 (U12) under an M8 lens holder with an 80° × 50.6° lens (L1).

Corner board: ESP32-S3-WROOM-1-N16R8 (U41, radio off: inside the aluminium rail the link is the wire), the 3.3 V buck and OV5640 supplies (U43), ATECC608B (U44, signs every frame it sends), ID chip (U45, left or right), two THVD1450 (U42C), the latched microSD (J41), the corner lead (J42) and factory pads (TP41). Corner head: the OV5640 (U46) under an M8 lens holder with a 60° × 46.8° lens (L41).

Rim board: ESP32-S3-MINI-1-N8 (U51), ISM330DHCX (U52) on the board screwed flat to the plate-side wall, THVD1450 (U53), the 3.3 V buck (U54), ID chip (U55), the latched microSD (J51), the rim lead (J52) and factory pads (TP51).

Light section: 14 WS2812B-class LEDs at 17 mm pitch (D1 to D14) over the slot; chain in and out (J61, J62) and a bulk capacitor (C61).

Digit board: two 7-segment digits of 130 × 70 mm with 7 LEDs a segment (DS…) and the point (DP1, DP2), the latched lead (J71) and a 1.5 A polyfuse with bulk capacitors (C71).

Power board: the push-in 3-pole mains terminal (J81) for the shot-clock feed, a 2 A slow-blow fuse and a varistor (F1A), the IRM-60-5 (PS1), the milled creepage slot (SLOT), the clock lead (J82) and the two digit leads (J83, J84), and the output filter (C81).

3. Every connection, checked

Link	How	Checked against
Top camera chip to RV1126B	4-lane MIPI CSI-2 across the 40 mm flex	IMX415: 3840 × 2160 at 30 fps uses 2.49 of 3.56 Gbps
Corner camera chip to ESP32-S3	8-bit camera port across the 30 mm flex, the OV5640 cropping to 2592 × 800 and making JPEG	OV5640 data sheet; ESP32-S3 LCD_CAM (est. 48 MHz pixel clock)
Corner boards to the main board	RS-485 at up to 4 Mbps, frames on request; a frame-sync pair	TI THVD1450; ESP32-S3 UART (up to 5 Mbps)
Rim board to the main board	RS-485, rim and net hits as events	TI THVD1450
Call lights and digits	five light chains and the digit line through 3.3 → 5 V line drivers	WS2812B data sheet; TI SN74AHCT125
Wi-Fi/BT	SDIO and UART on the main board	AMPAK AP6256 (RV1126B SDK)
Home to away backboard	Wi-Fi, every call signed by the sending board’s security chip	AP6256; ATECC608B
Power in	the shot-clock mains feed (120 or 230 V) into the push-in terminal, fuse, varistor, IRM-60-5 (Class II); the clock lead drops 0.08 V at 6.5 A	Mean Well IRM-60 data sheet (to read)
Cards	SD bus to the RV1126B; SPI to each ESP32-S3; latched sockets	Amphenol 101-00660 family drawing

Every mating pair is checked against the makers’ documents, never “same as” another board.

4. Heat

The aluminium frame is the heat sink: about 2.2 W from the RV1126B goes through the heat block into the top rail’s top wall (4 K/W est.), so the chip sits near 45 °C with the rail at 36 °C in a full summer gym. The top camera chip is 46 mm from the processor. The IRM-60-5 sits in the closed clock box at about 24 % load in play; its temperature there is logged on rev A.

5. Power budget per backboard (est.)

State	Draw
In play: main board, top camera, Wi-Fi	2.7 W
Two corner boards (OV5640 and ESP32-S3) and the rim board	1.9 W
Both clock faces showing red digits	7.2 W
End of a period: red rows all round and the yellow row at the 0.9 A chain cap, for 3 s	+22.5 W
Peak	34.5 W, 69 % of the 35 W allowed (50 W supply)

6. Factory test (every board, every time)

Spring-pin fixture on TP1, TP41 and TP51: 5 V in, the eFuse trip at 5 A, every rail, boot from the card, a frame of a test chart from the top camera and each corner head, the motion chip on a tap table, every LED on every section and digit board, the piezo against a sound-level meter, the tamper switch with a magnet, the security chips’ keys, the ID chips set to home or away and left or right. The power board is tested on its own behind an isolating transformer: hi-pot across the slot, 5 V under load.

7. Who makes what

One maker makes the two rigid-flex pieces and the small boards and assembles them (turnkey), and makes the leads to length. We supply the microSD cards with our software and the lenses focused for the court (est.). The quote pack is /build/courtone-quote.

8. Cost per backboard, electronics (est.)

Item	Per backboard
V1 core (RV1126B, LPDDR4X, eMMC, power, AP6256)	$30
IMX415 chip, M8 holder and lens	$14
Two corner boards’ chips (ESP32-S3, OV5640, lens, security)	$34
Rim board’s chips (ESP32-S3-MINI-1, ISM330DHCX)	$11
606 LEDs, line drivers and their supply parts	$24
IRM-60-5, mains terminal, fuse, varistor	$22
Boards (two rigid-flex pieces, rim, 29 sections, 2 digit boards, power), 1,000 sets	$45
Leads	$10
Assembly and test	$25
Four microSD cards with our software	$12
Total	about $227 (est.)

The bench backboard’s bought boards cost about $320 at qty 1 (Pi Zero 2 W, AI Camera, Matrix Bonnet, two LED panels, three XIAO boards, NeoPixel strips and the LRS-50-5), so our set is about $90 cheaper per backboard at 1,000 (est.).

9. Timeline

Step	When
Shape and placement (this page)	done, 4 Nov 2026
Rev T CAD: top camera slot, corner windows in the side faces, radio window, tone holes and the mains gland (drawn the same day); head brackets, magnet boss and the board set in the CAD next	next
Schematic, footprints, routing	Dec 2026 – Jan 2027
Rev A boards made and tested on one court	Mar 2027 (est.)

10. Still to check

The IMX415 behind an M8 lens for a 1/2.8-inch chip: a lens with 80° across and its sharpness at 8 m (est. until chosen).
The OV5640 crop and JPEG rate into the ESP32-S3 camera port, and the 4 Mbps frame transfer time on the dev kit.
Wi-Fi range from the radio window in the top rail’s back face to the scorer’s table and the other backboard.
The power board’s creepage and clearance once routed (IEC 62368-1), and the IRM-60-5’s temperature in the closed clock box.
The call lights’ and digits’ brightness from the far end of the court; FIBA 1.1.6, 1.1.7 and 5.6 read against them.

Sources

FIBA Official Basketball Rules 2026, Basketball Equipment: https://assets.fiba.basketball/image/upload/documents-corporate-fiba-official-rules-2026-equipment-v1-0.pdf
Rockchip RV1126B: https://www.rock-chips.com/
Sony IMX415: https://www.sony-semicon.com/en/products/is/security/index.html
OmniVision OV5640: https://www.ovt.com/
Espressif ESP32-S3-WROOM-1 and ESP32-S3-MINI-1: https://www.espressif.com/en/products/modules
ST ISM330DHCX: https://www.st.com/en/mems-and-sensors/ism330dhcx.html
AMPAK AP6256: https://www.ampak.com.tw/
Mean Well IRM-60: https://www.meanwell.com/
Worldsemi WS2812B: http://www.world-semi.com/
TI THVD1450: https://www.ti.com/product/THVD1450
Microchip ATECC608B: https://www.microchip.com/en-us/product/atecc608b
TI DRV5032: https://www.ti.com/product/DRV5032
The backboard: products/courtone/cad/courtone-cad.mjs (rev O; windows, tone holes, radio window and gland rev T); the boards: products/courtone/hardware/pcb/courtone-board.mjs

Design review (4 Nov 2026)

Every board is checked by the same rules (products/_shared/board-rules.mjs), one for each lesson any of our boards has taught us. CourtOne’s boards were made with every rule from the start: 24 pass, 4 fixed, 13 to prove, 0 fail. The full review, with every number and its source, is on the board page. It shows:

The top camera window (fixed): the ball through the net is 74° below level; an M8 lens low in the rail and an 18 × 39 slot pass every call with 1 mm to spare. Drawn in the CAD the same day.
The corner windows (fixed): from the front face the corner calls were up to 84° off; in the side faces the steepest is 61°.
Pixels: a shoe on the arc 30° off centre gets 33 px from the top camera and a shoe at the wing 33 px from a corner camera, against 20 needed.
The latched microSD is fitted on the main, corner and rim boards, and our software starts from it; updates never run during a game.
Conformal coating on every board, the power board’s mains side included.
Fast lines on a solid ground plane (to prove, lesson: planes, from the CricketOne test-board layout of 4 Nov 2026): RV1126B memory; 5 camera MIPI links (100 Ω pairs); USB (90 Ω); antenna feed (50 Ω, keep-out on every layer); card lines (length-matched, no vias under the socket). Ground on the layer next to the parts (inner layer 1, supply on inner layer 2; the whole bottom of a 2-layer section), one via beside each ground and supply pad and none in pads, no copper or vias in the antenna keep-out on any layer or under the card socket, the impedance lines routed first with a test coupon. The quote asks for it; the routed board’s design rule check proves it.
To prove on rev A: the AI time per frame, the corner frames’ transfer time, Wi-Fi through the radio window, the call lights and digits from across the court, the mains creepage and the supply’s temperature in the clock box, the tamper magnet, the head brackets and the boards in the rev T CAD.

The request for quote is /build/courtone-quote.