Our own circuit boards, in the gondola canopy

Boards we design for the smart aisle, with every chip soldered on them: the RK3576J processor and its memory, two 12 MP camera chips, the call lights, the call tone, the Wi-Fi module, the security chip and the mains supply. One rigid-flex piece lies on the canopy floor at the middle of each run, with the cameras turned out to the aisle ends and a light strip behind the opal cover; two small light boards sit at the run’s ends and a power board at the back takes the canopy’s own light feed. The same set goes in both runs. No bought modules, 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 canopy 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.

Show the canopy

Loading the 3D board…

Drag to turn · scroll to zoom · right-drag to move · click a partDrag to turn · tap a part

Where everything is in the canopy

Aisle camerasmiddle of the canopy

Two bare Sony IMX577 12 MP camera chips on small tabs off the main board, each under an 80° M12 lens that passes through the canopy cover to just inside its face, turned 30° out to its end of the aisle and 30° down: the opposite shelves end to end, every price label, and the floor up to the other run. People are masked out of every still; no faces.

Call lightsbehind the cover

A light strip stands just behind the opal cover in the middle of the run with 48 colour LEDs, and two small end boards carry 12 more each at the run’s ends: amber for a restock or a label, red for a spill or a person down, seen from both ends of the aisle.

Processor, radio and securitycanopy floor

The RK3576J with its memory on the main board, a heat block into the aluminium canopy, the Wi-Fi module behind the opal, the security chip that signs every call, the latched microSD card with our software, and a tamper sensor held by a magnet in the cover.

Call tonecanopy floor

A small piezo on the underside of the main board sounds through tone holes in the canopy floor when a spill or a blocked aisle is called.

Mains powerback of the canopy

A power board at the back takes the canopy’s own light 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 reaches the main board.

Two runs, one aisleboth canopies

Run B carries the same boards, turned round. Its calls go to run A over the store Wi-Fi, signed by its own security chip; run A merges both runs into one task list.

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

Laid flat: the main board with the camera tabs in front and the light strip above on F1; then the two end light boards and the power board. Tap the drawing to open it full size.

Design review: checked before we order

Every board-level number AisleOne'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 fails15 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	Left aisle camera: a price label's digits (8 mm) on the opposite top shelf at the aisle end at 2.71 m M12 lens, 80° across: about 50.7 px per degree across 4056 px. The label reader needs about 8 px per digit height (est.); smaller labels stay "check the label", never a wrong price.	8.6 px	≥ 8 px	to prove on the dev kit
Camera	Left aisle camera: frame rate the calls need A standard mode of the IMX577.	2 fps at 4056 × 3040	chip: 30 fps at 4056 × 3040	passes
Camera	Left aisle camera: data rate vs its 4-lane link 96 % spare on the link.	0.25 Gbps (10-bit)	≤ 80 % of 6 Gbps	passes
Camera	Right aisle camera: a price label's digits (8 mm) on the opposite top shelf at the aisle end at 2.71 m M12 lens, 80° across: about 50.7 px per degree across 4056 px. The label reader needs about 8 px per digit height (est.); smaller labels stay "check the label", never a wrong price.	8.6 px	≥ 8 px	to prove on the dev kit
Camera	Right aisle camera: frame rate the calls need A standard mode of the IMX577.	2 fps at 4056 × 3040	chip: 30 fps at 4056 × 3040	passes
Camera	Right aisle camera: data rate vs its 4-lane link 96 % spare on the link.	0.25 Gbps (10-bit)	≤ 80 % of 6 Gbps	passes
Camera	Image processor load, all cameras 2 cameras into one image processor.	49 Mpx/s	≤ 480 Mpx/s (RK3576J ISP)	passes
Camera	AI engine time per frame One small spill and person model (int8) on 2 fps crops of the floor, a gap model and a label reader on the 8 MP stills; run A also merges run B's calls. Measured on the dev kit.	6 TOPS	a floor check from both views twice a second, and a shelf-gap and label pass on a still every 10 min	to prove on the dev kit
Power	Supply About 5.5 W in open hours (RK3576J 3 W, two cameras 0.6 W, Wi-Fi 0.5 W, call lights at 10 % 1 W), a spill call with red lights at the 1 A strip limit and two end boards at 0.4 A each 9.5 W (est.): 68 % of the supply.	the canopy's own light feed (120 or 230 V) into a push-in terminal on the power board, a PCB-mount Mean Well IRM-20-5 (5 V 4 A, 20 W)	≤ 70 % of the supply (14 W)	passes
Power	Power cut Store mains are on in open hours; cutting the canopy feed mid-call is part of the rev A tests.	no cells: a power cut stops the board; every call and the task list are written to eMMC as they happen and signed	no lost call or task in a power cut	to prove on the dev kit
Heat	RK3576J temperature, the top of a store aisle in summer (28 °C) under the store lights The canopy sits 1.9 m up, near the ceiling lights, where the store is warmest; counted at 38 °C inside. 3 W through a 24 × 24 aluminium block and gap pads to the 3.66 m aluminium canopy floor (4 K/W, est.).	50 °C	≤ 85 °C (rated)	passes
Heat	Camera chips away from the processor A warm sensor adds noise to the floor check at night lighting levels.	left camera 86 mm, right camera 72 mm from the RK3576J	≥ 30 mm	passes
Shock	Shock and vibration A cart or a pallet jack hitting the gondola upright, and stock dropped on the canopy when the top shelf is filled (est.); the boards sit on stand-offs in the canopy, 1.9 m up. MEMS clocks are fitted anyway, and the card socket is latched.	50 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. Rev A and sale boards boot from the card; the eMMC holds no system copy (it ships empty, so the card always starts first: Rockchip tries the eMMC before the card) and keeps the call log. Updates write to the card with two system copies, only when the store is closed. The quote asks for U-Boot and a device tree from Rockchip's RK3576 SDK.	microSD socket with a hinged, latched lid (Amphenol 101-00660 class), fitted on every board: our software starts 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, U91 added (4 Nov 2026, CricketOne card-start review).	1 power switch and 1 ESD array for 1 card socket	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).	33.2 s of 8-bit 2 fps video in 40 % of the 2 GB memory	≥ 3 s	passes
Radio	Wi-Fi from inside an aluminium canopy The canopy is aluminium on three sides and over a steel gondola; only the opal front lets radio out, so the antenna sits right behind it, facing the aisle and the other run. Measured on rev A (lesson: antenna).	Wi-Fi 6 module on the light strip, its chip antenna 4 mm behind the opal cover, between the canopy's top and floor	certified Wi-Fi module, the store's WPA3 Wi-Fi; run B to run A across the aisle	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).	RK3576J memory; 2 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 Floor cleaning, a leaking freezer case nearby and stock sprayed or spilled on the top shelf; the power board carries mains, so all five 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	Camera chip and lens for the farthest price label With the cameras at the middle of the run, the farthest label (the opposite top shelf at the aisle end) is 2.7 m away. The bench-style 8 MP IMX415 under a 102° lens gave its digits 6.4 px, a fail. Every call sits within 34.8° across and 28.5° up-down of the axis, so a 4:3 12 MP chip under an 80° lens covers them all with more pixels per degree (lesson: camera). Change: Camera chip IMX415 → IMX577, lens 102° → 80° (4 Nov 2026).	Sony IMX577 12.3 MP (4:3) under an 80° × 64.4° lens: 50.7 px per degree	the label digits at the far aisle end ≥ 8 px, every call inside the view	fixed by the review
Camera	Every gap, label, spill, sign and person-down call in a camera view Every inView target from the CAD (the opposite bottom shelf front and top shelf at the end and the middle, the aisle floor at the end and at the opposite base deck, a person down in the near half) from the lens front's real place in the cover.	Left aisle camera: worst 34.8° / 28.5°; Right aisle camera: worst 34.8° / 28.5°	inside the 80 × 64.4° view	passes
Camera	Cameras a short flex from the processor The bench canopy had two Camera Module 3 boards at x ±915 on 1 m ribbons to the Pi 5, which the risk list already flagged. A camera chip must be a short flex from the processor, so both move to the middle of the run and turn 30° out; the CAD view check shows every call still in view, with the worst at 34.8° of the 51° half-view. Change: CAD rev T: cameras from x ±915 to x ±60, turned 30° out; windows 32 × 32 → 33 × 34 at the middle, opening outward (4 Nov 2026).	both camera chips at the middle of the run, turned 30° out to the aisle ends and 30° down, on 35 mm flex hinges (needs 31.1 mm)	MIPI on the board, no camera ribbons	fixed by the review
Camera	Camera windows in the canopy cover The lens passes through the 3 mm cover to 0.5 mm inside its face; the floor at the aisle end is the steepest line of sight (71° from the cover), so each window opens 22 mm outward from its axis (lesson: window).	left view reaches 19.2 mm out from its axis (steepest 71° from the cover); margins 2.5 and 2.5 mm	rev T windows 33 × 34, x ±49 to ±82	passes
Fit	Camera tabs on their brackets Each tab hangs off the main board's front edge and is held on its camera's axis by a printed bracket clipped to the canopy floor; the brackets go in the rev T CAD and are checked in 3D there (lesson: fit3d).	Left aisle camera: holder 0.3 mm behind the cover, barrel 7.1 mm, hinge 31.1 mm, lowest corner 1865.5 mm; Right aisle camera: holder 0.3 mm behind the cover, barrel 7.1 mm, hinge 31.1 mm, lowest corner 1865.5 mm	holder ≥ 0.3 mm off the cover, hinge within the flex, clear of the canopy floor and the light strip	to prove on the dev kit
Light	Call lights behind the opal cover The bench used four NeoPixel sticks per canopy; on our boards the LEDs sit where the sticks were and in the middle. Their evenness through the opal and the brightness from the aisle end are checked on rev A.	48 RGB LEDs at 12.8 mm pitch across the middle 614 mm and 12 on each end board at x ±1,400, 4 mm behind the cover	the call seen from both aisle ends; amber and red told apart; never glaring	to prove on the dev kit
Fit	Leads along the canopy floor The end call lights sit 1.4 m from the middle so the call shows over the spot at either end; no board spans that, so two small light boards hang on latched, keyed 3-pin leads with a line driver on the main board.	L1 about 0.47 m of 18 AWG, 0.05 V drop at 2.4 A; L2 and L3 about 1.39 m of 24 AWG, 0.09 V drop at 0.4 A	L1 ≤ 0.15 V; L2 and L3 ≤ 0.3 V (the LEDs need 4.5 V or more, est.)	passes
Power	Mains on the power board The bench used a potted IRM-20-5 on flying leads; on our power board the same module is soldered with a slot under its input. The creepage is measured from the routed board, and UL 962 and UL 62368-1 are still to be done.	push-in 3-pole terminal, 1 A slow-blow fuse and varistor, PCB-mount IRM-20-5 (Class II), 2 mm milled slot and 6 mm keep-out between the mains and 5 V sides	creepage and clearance per IEC 62368-1 (est. 6 mm reinforced at 250 V); the store's electrician wires the light feed	to prove on the dev kit
Security	Cover tamper sensor The bench used a plunger switch pressed by the cover; on our board a Hall switch needs no boss. The magnet pocket goes in the rev T CAD and the switch point is measured on rev A.	DRV5032 Hall switch on the light strip 4 mm behind the canopy cover, held by a Ø6 × 3 magnet bonded in the cover	cover opened = logged and signed	to prove on the dev kit
Fit	Flex length F1 carries the call-light data and the Wi-Fi module's SDIO; the flex maker confirms the SDIO impedance over that length.	F1 70 mm up to the light strip	routed and held in the rev T CAD	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:

Left aisle camera: a price label's digits (8 mm) on the opposite top shelf at the aisle end at 2.71 m
Right aisle camera: a price label's digits (8 mm) on the opposite top shelf at the aisle end at 2.71 m
AI engine time per frame
Power cut
Card grade
Wi-Fi from inside an aluminium canopy
Fast lines on a solid ground plane
Board inside the product CAD, every part checked in 3D
Camera tabs on their brackets
Call lights behind the opal cover
Mains on the power board
Cover tamper sensor
Flex length

Where the design stands

1Shape and placementdone
Main board, camera tabs, light strip, two end boards and the power board in the canopy’s shape, all 110 parts placed at their real size, every aisle call checked from where each lens sits, and KiCad design rule check (0 violations).
2Schematicnext
Every wire between the chips, from the V2 core and C1 camera circuits.
3Footprintsnext
The exact solder pads under each chip.
4Routinglater
Copper tracks on all layers, along the light strip and the flexes, with the mains spacing on the power board.
5Files for the makerlater
Gerbers with copper, drill, mask, paste, the rigid-flex drawing, 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 in one aisle.

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 boardaisleone-board.kicad_pcb: open with KiCad 10 (free)3D model (STEP)The bare boards for mechanical CAD Side A drawing (PDF)Down to the canopy floor, out to the cover Side B drawing (PDF)Up into the canopy Parts and placement (CSV)Every part, its size, side and position

Who can make it

Each canopy set is an 8-layer rigid-flex piece with a 640 mm light strip, plus three small boards and three leads made to length; an aisle takes two sets. It needs a maker who builds rigid-flex boards with long panels 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 110 parts, what is on each board, every connection, heat, power, the factory test, cost and timeline.

AisleOne: circuit boards of our own

What changed (4 Nov 2026). The rev A bench aisle is built from bought boards joined by leads and ribbons: a Raspberry Pi 5 in each canopy, two Camera Module 3 Wide boards on 1 m ribbons at x ±915, four NeoPixel sticks, a piezo, an ATECC608 board, a plunger tamper switch and a potted IRM-20-5 on flying leads. AisleOne now gets boards of our own, like CricketOne, on our board platform. The same set goes in both runs: run A’s merges the aisle and keeps the task list; run B’s, turned round, sends its calls to run A over the store Wi-Fi.

The chips: the V2 core (Rockchip RK3576J, 2 GB LPDDR4X, 16 GB eMMC, AMPAK AP6275S Wi-Fi 6/BT module), two bare Sony IMX577 12 MP camera chips under M12 lens holders (the C1 camera on the board), 72 RGB call-light LEDs, an SMD piezo, the security chip, a Hall tamper switch and a PCB-mount Mean Well IRM-20-5.
The shape: in each canopy, one rigid-flex piece: an 8-layer main board (180 × 84 mm) flat on the canopy floor at the middle of the run; two 16 × 16 mm camera tabs on 35 mm flex hinges off its front edge, each held on its camera’s axis by a printed bracket; a 4-layer light strip (640 × 20 mm) standing 4 mm behind the opal cover on a 16 mm flex (F1). Two 2-layer end light boards (200 × 18 mm) behind the cover at x ±1,400 on latched leads, and a 2-layer power board (100 × 60 mm) at the back of the canopy floor with the mains terminal and the supply.
The cameras move to the middle (fixed): a camera chip must be a short flex from the processor, not a 1 m ribbon, so both cameras now sit at x ±60, turned 30° out to the aisle ends and 30° down. The CAD’s view check shows every one of the 28 calls still in view (rev T CAD, the same day).
A bigger camera chip (fixed): from the middle, the farthest price label (the opposite top shelf at the aisle end) is 2.7 m away. The 8 MP IMX415 under a 102° lens gave its digits 6.4 px, under the 8 px the label reader needs. Every call sits within 34.8° across and 28.5° up-down of the camera’s axis, so a 4:3 12 MP IMX577 under an 80° lens covers them all and gives the digits 8.6 px (to prove on rev A).
Made from the shared rules: MEMS clocks, the latched microSD card with our software on every board, conformal coating, the antenna checked for the aluminium canopy on rev A, cameras 30 mm or more from the processor, the lens chosen from the calls and its front just inside the cover (lesson: window).

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

1. The shape: five boards per run

Piece	Size	Layers	Where	What
Main board	180 × 84 mm, 1.6 mm	8	flat in the canopy, side A 10 mm over the aluminium floor, at the middle of the run	the V2 core, card, security, call tone, camera supplies, LED line driver, power and light headers
Camera tabs (2)	16 × 16 mm, 0.8 mm, on 35 mm flex hinges	8	off the main board’s front edge at x ±60, turned 30° out and 30° down	IMX577 and M12 lens holder each, lens front 0.5 mm inside the cover’s face
Light strip	640 × 20 mm, 1.6 mm	4	standing 4 mm behind the opal cover above the camera windows, on F1 (70 mm)	48 call-light LEDs, Wi-Fi/BT module, cover tamper switch
End light boards (2)	200 × 18 mm, 1.6 mm	2	standing 4 mm behind the cover at x ±1,400	12 call-light LEDs, latched 3-pin header, polyfuse
Power board	100 × 60 mm, 1.6 mm	2	on 6 mm stand-offs at the back of the canopy floor, x −330 to −230	push-in mains terminal, fuse and varistor, IRM-20-5, creepage slot, latched 2-pin header

Leads: L1 (power board to main board, 5 V, about 0.5 m of 18 AWG, Molex Micro-Fit 3.0 2-pin latched); L2 and L3 (main board to the end boards, about 1.4 m of 24 AWG each, JST GH 3-pin latched: 5 V, GND, LED data), along the canopy floor.

2. What is on the boards

Main board, side A (down, to the canopy floor): RK3576J (U1) with a 24 × 24 aluminium heat block and gap pads to the canopy floor (HS1), LPDDR4X (U2), eMMC (U11), the SMD piezo (BZ1) over the tone holes.

Main board, side B (up): the RK3576J decoupling field (C1), RK806S power (U3), 24 MHz and 32 kHz MEMS oscillators (Y1, Y2), ATECC608B (U8) and the ID chip (U9, which also says run A or B), the latched microSD socket (J1), reached by taking off the canopy cover, the eFuse (U42), the latched power header (J2) and light headers (J3, J5), the SN74AHCT125 line driver (U36), the camera supplies (U21, U22) and the factory pads (TP1).

Camera tabs: an IMX577 (U200, U210) under an M12 lens holder with an 80° × 64.4° lens (LH1, LH2) on each, turned 30° out and 30° down at the opposite run and the floor; people are masked out of every still, never faces.

Light strip, side A (to the cover): 48 WS2812B-class LEDs at 12.8 mm pitch (D1–D48: amber for a restock or a label, red for a spill or a person down, green when cleared), the AP6275S Wi-Fi/BT module (U5) with its antenna keep-out (ANT1) behind the opal, the DRV5032 cover tamper switch (U7) under a magnet in the cover. Side B: the call lights’ power and 1 A limit (U37).

End light boards: 12 WS2812B-class LEDs each (DL1–DL12, DR1–DR12), the latched 3-pin header (J6, J7) and a polyfuse with bulk capacitor (C8, C9).

Power board: the push-in 3-pole mains terminal (J8) for the canopy light feed, a 1 A slow-blow fuse and a varistor (F1A), the IRM-20-5 (PS1), a milled creepage slot (SLOT) and the latched 5 V header (J9).

3. Every connection, checked

Link	How	Checked against
Camera chips to RK3576J	4-lane MIPI CSI-2 each, across the 35 mm flex hinges	IMX577: 4056 × 3040 at 30 fps; at 2 fps each uses 0.25 Gbps of its link (est. 1.5 Gbps per lane, data sheet to read)
Call lights	one data line up F1; two over L2 and L3 through a 3.3 → 5 V line driver	WS2812B data sheet; TI SN74AHCT125
Wi-Fi/BT	SDIO and UART up F1	AMPAK AP6275S (RK3576 SDK default)
Call tone	PWM from the RK3576J through a small driver to the piezo	PUI Audio AT-1220 class (est.)
Run B to run A	the store’s WPA3 Wi-Fi; every call signed by the sending run’s security chip	AP6275S; ATECC608B
Power in	canopy light feed (120 or 230 V) into the push-in terminal, fuse, varistor, IRM-20-5 (Class II); L1 drops 0.05 V at 2.4 A	Mean Well IRM-20 data sheet
Card	SD bus to the RK3576J, latched socket	Amphenol 101-00660 family drawing

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

4. Heat

The 3.66 m aluminium canopy is the heat sink: about 3 W from the RK3576J goes through the heat block into the canopy floor (4 K/W est.), so the chip sits near 50 °C with the canopy at 38 °C under the store lights. The IRM-20-5 sits 240 mm from the processor at the back of the canopy. The camera chips are 86 mm and 72 mm from the processor.

5. Power budget per run (est.)

State	Draw
Open hours: floor check 2 fps, a still every 10 min (RK3576J, two cameras, Wi-Fi)	4.1 W
Call lights at 10 %, security, tone idle	1.4 W
Spill call: middle strip at its 1 A limit, end boards at 0.4 A each, tone	up to 9.5 W
Peak	9.5 W, 68 % of the 14 W allowed (20 W supply)
Closed: tamper and after-hours watch, processor mostly asleep	1.5 W

6. Factory test (every board, every time)

Spring-pin fixture on TP1 and the small boards’ pads: 5 V in on L1, the eFuse trip at 3.5 A, every rail, boot from the card, a frame of a test chart from each camera, all 72 LEDs, the piezo against a sound-level meter, the tamper switch with a magnet, the security chip’s key, the ID chip set to run A or B. 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 rigid-flex piece and the three small boards and assembles them (turnkey), and makes the three leads to length. We supply the microSD cards with our software and the lenses focused at 2.5 m (est.). The quote pack is /build/aisleone-quote.

8. Cost per aisle, electronics (est.)

Item	Per run	Per aisle
V2 core (RK3576J, LPDDR4X, eMMC, power, AP6275S)	$42	$84
Two IMX577 camera chips, holders and lenses	$36	$72
72 LEDs, line driver and their power	$7	$14
Piezo, security, ID, Hall switch, eFuse, socket, passives	$6	$12
IRM-20-5, mains terminal, fuse, varistor	$14	$28
Boards (8-layer rigid-flex with a 640 mm strip, three small boards), 1,000 runs	$26	$52
Three leads	$4	$8
Assembly and test	$12	$24
microSD card with our software	$4	$8
Total	about $151	about $302 (est.)

The bench canopies’ bought boards cost about $480 per aisle at qty 1 (two Pi 5s, four Camera Module 3 Wide boards, eight NeoPixel sticks and the small boards), so our boards are about $180 cheaper per aisle at 1,000 (est.).

9. Timeline

Step	When
Shape and placement (this page)	done, 4 Nov 2026
Rev T CAD: cameras and windows at the middle of each run, tone holes under the board (drawn the same day); camera brackets, magnet pocket and the board set in the CAD next	next
Schematic, footprints, routing	Dec 2026 – Jan 2027
Rev A boards made and tested in one aisle	Mar 2027 (est.)

10. Still to check

The IMX577’s package, supplies and lane rate from Sony’s data sheet, and its driver in Rockchip’s RK3576 SDK (est. until read).
The 80° lens for a 1/2.3-type chip: its real view and sharpness at 2.7 m, and the label digits on rev A (8.6 px against 8 needed).
Wi-Fi range from inside the aluminium canopy, run B to run A across the aisle (antenna behind the opal).
The power board’s creepage and clearance once routed (IEC 62368-1), UL 962 for the gondola with its light feed.
The 640 mm light strip’s panel length and the F1 SDIO impedance with the maker.

Sources

Rockchip RK3576 brief: https://www.rock-chips.com/a/en/products/RK35_Series/2024/0524/1977.html
Sony IMX577 (12.3 MP, 1/2.3-type): https://www.sony-semicon.com/en/products/is/industry/index.html
AMPAK AP6275S: https://www.ampak.com.tw/
Mean Well IRM-20 data sheet: https://www.meanwell.com/Upload/PDF/IRM-20/IRM-20-SPEC.PDF
Worldsemi WS2812B: http://www.world-semi.com/
TI SN74AHCT125: https://www.ti.com/product/SN74AHCT125
Microchip ATECC608B: https://www.microchip.com/en-us/product/atecc608b
TI DRV5032: https://www.ti.com/product/DRV5032
The aisle: products/aisleone/cad/aisleone-cad.mjs (rev A, cameras, windows and tone holes rev T); the boards: products/aisleone/hardware/pcb/aisleone-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. AisleOne’s boards were made with every rule from the start: 15 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 cameras a short flex from the processor (fixed): both move from the 1 m ribbons at x ±915 to the middle of the run, turned 30° out; every one of the 28 calls stays in view, the worst at 34.8° across and 28.5° up-down. Drawn in the CAD the same day.
The farthest price label (fixed): from the middle, the label at the far aisle end is 2.7 m away; the 8 MP chip under 102° gave 6.4 px, so the board takes a 12 MP 4:3 chip under an 80° lens: 8.6 px against 8, little spare, so it is proved on rev A.
Camera windows: the floor at the aisle end is the steepest line of sight (71° from the cover), so each 33 × 34 window opens outward from its axis (lesson: window).
The latched microSD (J1) is fitted, and our software starts from it; updates run only when the store is closed.
Conformal coating on all five boards, 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): RK3576J memory; 2 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 label digits, the AI time per check, Wi-Fi from inside the canopy, the camera brackets, the call lights through the opal, the mains creepage, the tamper magnet, the flex and the boards in the rev T CAD.

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