Doc 9 · Understand the PCB — LIGHT v0.2, the Integrated Board

Engineered Lighting prototype series · September 2026

Open the PCB build shopping checklist →

Order the remaining parts for two fixtures: motors, optics, diffuser, mounting supplies and exact cable-side connectors. Check off purchases as you order; selection notes identify the items still needing a fit or specification decision.

Everything the bench proved and Doc 8 hand-soldered has been drawn as one circuit board: a 76.2 × 75.1 mm disc with a flat under the antenna, eight copper layers, and parts on both faces. One ESP32-C6 module, two PWM expanders, 21 ambient channels, three constant-current spotlight drivers, a CAN transceiver for the motors, and a protected 24 V supply feeding all of it.

This chapter is for understanding that board before it exists in your hands. Turn it over, click any part and find out what it does there — not what a resistor does in general, but what this resistor does on this net. The schematic, the parts list and the actual KiCad files are all here too.

Where this sits after Doc 8

Doc 8 is the previous stage: the bench architecture hand-soldered onto three round protoboards, with a dev-kit ESP32, PCA9685 breakouts, ULN2803 arrays and a PicoBuck driver, fed by an internal 24 V supply. It works, and it is how the design was learned.

This board is the next stage, and it is not the same machine. The switching is done by 21 discrete MOSFETs rather than Darlington arrays; the spotlights get three independent constant-current drivers rather than one shared board; the power path gains an electronic breaker, a supervisor and a physical ARM interlock. Doc 8's parts, wiring and ESPHome examples are not this board's implementation, and the bench measurements in Docs 3 and 4 are not measurements of this PCB.

Status as of 8 September 2026 — designed, not built

This page shows the latest grouped arm connectors and branding revision, cbb8d9fc, submitted to PCBWay for quotation and engineering review with 241 fitted parts per assembled board. The request is five fabricated main boards: two fully assembled on both sides with sourced components, and three supplied bare. Earlier main revisions were also submitted to JLCPCB. No payment, procurement or production release is authorized. Supplier stack, stencil, via treatment, final capacitor installation and substitutions remain open.

No LIGHT v0.2 PCB has been powered. Current DRC and native/export preservation checks bind the branded board to the electrically reviewed 80195efd baseline. That baseline has ERC, pin-parity, connectivity and independent CAM evidence. Those checks are not physical tests or a new simulation.

Doc 10 covers the unchanged three flex circuits. The static gimbal has a PCBWay inquiry, as do the upper and lower LED flexes: two of each for two fixture prototypes. The quote-form copper and upper-tail support/finish placeholders require engineering correction; they do not change the specified construction. Assembly inspection settings also await correction. Their geometry and hashes have not been revised for this update.

Latest changes: arm connectors and branding

The three two-pin spotlight sockets became one six-pin J9 beside the separate J13 tilt connection. Pins 1/2, 3/4 and 5/6 carry spotlight channels 1, 2 and 3. Their LED-minus wires remain independent driver returns: sharing a connector does not make them ground. J12 pan remains a separate edge connection because its cable terminates at the pan motor.

Wires link J9 and J13 to the static arm flex. The wire service loop must accommodate pan motion of 180 degrees each way; the static flex itself is not qualified as a repeatedly bending hinge.

The underside now carries the small orbit logo, engineered lighting, the website and the Louis Kahn quotation. This branding changed only back silkscreen. Black substrate, white ink, metallic pads and the overhanging ESP32 depiction remain illustrative viewer materials, not an as-built photo.

The revision sequence is 9c42ff8d (central LED interface), 80195efd (grouped arm connectors), then cbb8d9fc (back-side branding). The upper insertion tail and lower/gimbal boards are unchanged.

Words this chapter uses — open this if any of them are new

Word	What it means here
Schematic	The drawing of what connects to what. It says nothing about where parts sit.
Layout	The drawing of where everything physically goes. This page's viewer shows the layout.
Reference designator	A part's address on this design: U1, R101, J14. The letter hints at the kind of part (R resistor, C capacitor, U integrated circuit, Q transistor, D diode, L inductor, F fuse, J connector, S switch, TP test point, H mounting hole), and the number identifies the instance. It is not the part's value, and the prefix alone never explains what a part does.
Net	One electrical connection, everything joined to it. GND is a net; so is ZONE1_W.
Trace	The physical copper that implements part of a net. A schematic line is a connection, not a scale drawing of a wire — one line can become a trace that crosses three layers.
Rail	A net that distributes power: +3V3, +5V, V24_BUS.
Ground	The circuit's voltage reference and return path. It is not automatically an earth connection.
Pin vs GPIO	A chip's physical pin number and its software name are different things. On this board, module pad 25 is the serial transmit line the firmware calls GPIO16.
Layer	One sheet of copper inside the board. This one has eight, with insulating material between them.
Via	A small plated hole that carries a net from one layer to another.
Pad	Exposed copper a part's pin solders to. A pad belongs to the board, not to the part.
No-connect	A pin deliberately left unconnected, marked so the design tools know it is intentional. This board has 29 of them.
Silkscreen	Printed ink labels. Ink, not copper, and not a connection.
Solder mask	The insulating coating over the copper. Its artwork describes the openings where copper is left exposed — so a "mask" view shows holes in the coating, not the coating.
Fab / assembly outline	A drawing layer showing component bodies and orientation for assembly. Not electrical.
Courtyard	The clearance a part reserves around itself so neighbours can be placed and soldered. Nothing physical.
BOM	Bill of materials: the parts list. Distinct from fabrication outputs (Gerbers, drill files), which describe the bare board itself.
Bare PCB vs PCBA	A bare PCB is the board alone. PCB assembly (PCBA) is that board with the parts fitted and soldered. They are quoted, priced and ordered separately.
ERC / DRC	Electrical-rule and design-rule checks: automated checks that the schematic and the layout obey stated rules. They do not run the circuit.

One more, because it matters on this page: an animated path showing where current would flow is an explanation. It is not a live electrical measurement.

The board

Start with U1 at the top — the radio module, the part that overhangs the flat edge. Then find J1 on the left, where the 24 V supply lands. Hover or tap any part to see what it does; use Flip face to see the underside, where the power section and the big capacitor live. The reference labels here are the same ones used in the schematic and in the parts list.

The interactive viewer needs JavaScript. Without it, use the assembly drawings, the parts index and the connector pinmaps below, or the complete schematic PDF. Every part on this page is explained in the parts index whether or not the viewer runs.

What this view shows — and what it does not

The default Components view is an assembly-outline view: real positions, real body outlines from the board's own fabrication layer, real land shapes from its pad data, and the actual reference labels. It is not a photograph and not a 3D render. The project includes references to KiCad library 3D models, but no assembled model of this board has been produced or verified, and none is published here.

The black ground is the specified solder-mask colour of a board that has not been manufactured. Layer colours are view colours chosen for contrast — copper is not orange, and the inner layers are not green and pink. The mask views show the openings where copper stays exposed, not the coating. Courtyard is placement clearance, not a physical feature.

Some parts overhang the board edge on purpose: the radio module past the flat, the USB connector at the bottom and one connector on the right. They are drawn unclipped, because that is where they really are. Turning the board over mirrors the whole geometry once about the board's centre line, so what you see is the physical back face, not a mirror image of the front.

Inspecting a part. Hovering one opens a short summary. Clicking or tapping it pins that summary, so it stays put and gains its own buttons: jump to the part's row in the parts list, open its schematic sheet, or drop to the full explanation. Nothing moves the page until you press one of those buttons — which is what makes this usable on a phone, where there is no hover and where the parts list is a long way down. The pinned summary closes with its ×, with Esc, or by tapping bare board; the selection itself survives all three.

Getting around: drag to pan, scroll or pinch to zoom, double-click to zoom in. The toolbar has zoom, fit and flip buttons for anyone not using a mouse. With the viewer focused, the arrow keys pan, + and - zoom, 0 fits the board and f flips it. The search box finds any of the 262 features by reference, name, value, part number or net — that is the fastest route on a phone, and the keyboard-friendly one.

On a phone, one finger scrolls the page as usual and two fingers pan and zoom the board. If you would rather drag the board with one finger, press Lock board for panning.

Earlier changes: the central LED interface

The first published layout was LIGHT v0.1 (c046202e). This page now shows LIGHT v0.2 (cbb8d9fc), paired with upper flex v0.3 (0af25f8f). Lower flex and the static arm ribbon remain v0.2: their native board bytes did not change.

Six radial LED sockets have become one locking Molex 2005280300 at J2, on the left side of the front face. J3–J7 have been removed. The upper flex's tail is the plug itself; no twenty-four-wire solder harness is needed between it and the main board. Thirty contacts provide twenty-four distinct connections: each zone gets two positive contacts and its own warm, neutral and cool switched returns. Sharing a connector does not join the six fused positive rails. Zone 7 still uses J8 on the underside. Motor, spotlight, USB, ARM and expansion interfaces and the four M3 mounting holes remain.

Routing this interface required local part moves and new signal paths on In2, which also carries 24 V copper. The reviewed ground references remain, but they are not uninterrupted sheets. PWM03 crosses a 1.465544 mm interruption caused by the inherited PCA_OE routing on In3. The adjacent/reference copper was reviewed; edge noise and coupling still need measurements on the prototype. An autorouter's completed connection is not proof of a good high-frequency return path.

The earlier audit corrections are included too: U5 is now 74HCS08PWJ with Schmitt inputs, R526–R528 are 910 Ω, and C504 has a provisional custom land without paste. Its one-reflow limit requires final factory installation. These changes explain why old timing or power calculations cannot simply acquire the new board hash. The source now has 262 features, 241 fitted packages, 71 BOM rows and 20 schematic sheets, including the shared interface sheet.

Flip to the back to see the white orbit logo, engineered lighting, website and quotation. The black-and-white finish is a fabrication request, not a photo of a built board.

How the circuit works

Each heading below names the parts involved; select any reference to jump to it on the board. Facts are tagged so you can tell a design intention from a CAD result from an open question.

24 V in, and what guards it

External 24 V arrives at J1 — pin 1 positive, pin 2 return — and meets F1, a 6.3 A backup fuse. D500 clamps incoming spikes. Q500 is a reverse-blocking transistor: connect the supply backwards and nothing downstream sees it. U12 is the real protection: an electronic breaker that limits current, ramps its output up gently, watches for over- and undervoltage and reports what it sees. Its behaviour is set by the resistors around it, not by software.

The mains supply is a separate unit. Mains never enters this PCB.

The protected bus, and the branches off it

Past the breaker the rail is V24_BUS. C504, the 1000 µF can on the back, is the local energy store that absorbs the motors' current spikes. U501 clamps transients close to where they arrive, and J16 taps the protected bus for a brake that has not been designed yet.

Every branch leaves through its own fuse: F2 and F3 for the two motors, F4–F10 for the seven ambient zones, F11 for the logic branch. A fuse rating protects the wiring; it is not a statement about what the copper can carry, and it is not a current limit.

Making 5 V and 3.3 V

U10 converts 24 V to 5 V through L500; U11 converts 5 V to 3.3 V through L501. Both are switching converters, which chop their input and let an inductor average the result — far more efficient than burning off the difference as heat. The 5 V budget is about 0.8 A in total, counting the 3.3 V converter's own draw and the CAN transceiver. That is not 0.8 A of spare accessory power.

The controller

U1 is an ESP32-C6 module: chip, flash, crystal and printed antenna, pre-certified as a unit. R1 and C1 hold it in reset while 3.3 V rises; S1 restarts it and S2 selects its download mode; J15 is the serial console. Its pad numbers are not GPIO numbers — read the map, do not count pins.

The 21 ambient channels

Two PWM expanders, U2 at address 0x40 and U3 at 0x41, generate the dimming waveforms. Each of the 21 channels is the same four parts: a 220 Ω gate resistor, a 100 kΩ pull-down, a 2.2 kΩ pull-up to the switched gate-bias rail, and an AO3422 MOSFET that completes the LED circuit to ground.

Two details decide whether firmware works on the first try. The expander outputs are open-drain: they can only pull down, so releasing an output is what turns a channel on, and the optical duty is the complement of what you write. And the second expander's outputs are remapped by routing — logical channel 18 is its output 13, logical channel 20 is its output 12. Never subtract 16.

Logical channel	Zone and colour	Expander output	Package pin	Gate resistor	Switch	Leaves at	Fused by
1	Zone 1 warm	U2 output 0	6	R101	Q101	J2 contact 18	F4
2	Zone 1 neutral	U2 output 1	7	R102	Q102	J2 contact 19	F4
3	Zone 1 cool	U2 output 2	8	R103	Q103	J2 contact 20	F4
4	Zone 2 warm	U2 output 3	9	R104	Q104	J2 contact 23	F5
5	Zone 2 neutral	U2 output 4	10	R105	Q105	J2 contact 24	F5
6	Zone 2 cool	U2 output 5	11	R106	Q106	J2 contact 25	F5
7	Zone 3 warm	U2 output 6	12	R107	Q107	J2 contact 28	F6
8	Zone 3 neutral	U2 output 7	13	R108	Q108	J2 contact 29	F6
9	Zone 3 cool	U2 output 8	15	R109	Q109	J2 contact 30	F6
10	Zone 4 warm	U2 output 9	16	R110	Q110	J2 contact 3	F7
11	Zone 4 neutral	U2 output 10	17	R111	Q111	J2 contact 4	F7
12	Zone 4 cool	U2 output 11	18	R112	Q112	J2 contact 5	F7
13	Zone 5 warm	U2 output 12	19	R113	Q113	J2 contact 8	F8
14	Zone 5 neutral	U2 output 13	20	R114	Q114	J2 contact 9	F8
15	Zone 5 cool	U2 output 14	21	R115	Q115	J2 contact 10	F8
16	Zone 6 warm	U3 output 0	6	R116	Q116	J2 contact 13	F9
17	Zone 6 neutral	U3 output 1	7	R117	Q117	J2 contact 14	F9
18	Zone 6 cool	U3 output 13 (remapped)	20	R118	Q118	J2 contact 15	F9
19	Zone 7 warm	U3 output 3	9	R119	Q119	J8 contact 2	F10
20	Zone 7 neutral	U3 output 12 (remapped)	19	R120	Q120	J8 contact 3	F10
21	Zone 7 cool	U3 output 5	11	R121	Q121	J8 contact 4	F10

Warm, neutral and cool in one zone share a positive wire, so their duties are scheduled not to overlap: d_warm + d_neutral + d_cool ≤ 1 per zone, in non-overlapping slots.

The three spotlights

U14 gates the spotlight supply, and U7, U8 and U9 each regulate one LED pair to a nominal 333 mA — a calculation from a 0.300 Ω sense resistor and the driver's sense window, not a measurement. Each channel's LED-minus returns through its own inductor. It is not ground, and joining two of them together breaks the regulation.

ARM, the supervisor, and SAFE

Nothing lights unless three things agree. The firmware raises LIGHT_ENABLE; the physical ARM switch on J17 must be closed; and U18, a supply supervisor, must confirm the 3.3 V rail is genuinely up. U5 ANDs the first two, U19 ANDs that with the supervisor, and the result — LIGHT_ENABLE_SAFE — powers the gate-bias switch U13, releases the spotlight supply and, inverted by U6, enables the expanders' outputs.

SAFE gates lighting only. It does not remove motor power, and it is not a watchdog on the controller. After a supply fault the firmware must reinitialise and be armed again; no lighting command may be silently restored.

CAN and the motors

U4 turns the controller's logic-level CAN into the differential pair that reaches both motors through J12 and J13, each with its own fused 24 V feed. R22 and the open solder jumper JP1 are the optional bus terminator — close it only if this board is one of the bus's two ends. This PCB powers the smart motors and talks to them; it does not implement their internal drive electronics.

The USB island

J14 is USB-C for programming and the serial console, and it needs external 24 V present: USB powers only a small sensing and isolation island, never the controller. U17 parks the controller's data lines on grounded resistors until the supervisor says the 3.3 V rail is qualified, and only then connects the host.

Temperature, expansion, and the mechanics

U20 measures local PCB temperature at I²C address 0x48. It is a digital sensor, not a thermistor, and it is not an overtemperature cutoff. J18 is seven bare pads — 3.3 V, ground and five spare GPIOs — with no header fitted and no spare power budget implied. TP13–TP15 are boot-strap probes, not expansion pins.

Four M3 holes form a trapezoid, so the board fits its mounts one way round. "Up" and "down" for the connectors mean perpendicular to the board's faces, not toward any edge: J1 mates upward from the front; the motor, spotlight and seventh-zone sockets mate downward from the back.

Connectors and pinmaps

Contact numbers below are PCB contact numbers, not a left-to-right view of a cable plug — a wire-entry view reverses a mating-face view. Use the numbered lands and the manufacturer's cavity drawing when making harnesses.

Port	What plugs in	Face	How it mates	Contacts in numeric order	Mating hardware
J1	the only power inlet: 24 V from the external supply	front	mates upward, out of the front face	1 = VIN24_RAW, 2 = GND	Phoenix 1771091 top-entry spring terminal -- wires go straight in, there is no mating plug. 0.5 mm2 / AWG20 conductors, 6 mm strip length.
J2	all six radial zones, separately fused	front	locking direct-insertion tail, gold facing the main board	1 = ZONE4_24V, 2 = ZONE4_24V, 3 = ZONE4_W, 4 = ZONE4_N, 5 = ZONE4_C, 6 = ZONE5_24V, 7 = ZONE5_24V, 8 = ZONE5_W, 9 = ZONE5_N, 10 = ZONE5_C, 11 = ZONE6_24V, 12 = ZONE6_24V, 13 = ZONE6_W, 14 = ZONE6_N, 15 = ZONE6_C, 16 = ZONE1_24V, 17 = ZONE1_24V, 18 = ZONE1_W, 19 = ZONE1_N, 20 = ZONE1_C, 21 = ZONE2_24V, 22 = ZONE2_24V, 23 = ZONE2_W, 24 = ZONE2_N, 25 = ZONE2_C, 26 = ZONE3_24V, 27 = ZONE3_24V, 28 = ZONE3_W, 29 = ZONE3_N, 30 = ZONE3_C	Molex 2005280300, bottom-contact Front Flip, 30 contacts at 1 mm pitch. Upper flex J100 inserts directly; total insertion thickness 0.30 +/-0.05 mm. No solder on the fingers.
J8	ambient zone 7 (the bottom ring)	back	mates downward, out of the back face	1 = ZONE7_24V, 2 = ZONE7_W, 3 = ZONE7_N, 4 = ZONE7_C	JST GH 4-way vertical BM04B-GHS-TBT, mating GHR-04V-S
J9	all three independent spotlight LED pairs	back	mates downward beside the tilt harness	1 = SPOT1_LED_PLUS, 2 = SPOT1_LED_MINUS, 3 = SPOT2_LED_PLUS, 4 = SPOT2_LED_MINUS, 5 = SPOT3_LED_PLUS, 6 = SPOT3_LED_MINUS	JST GH 6-way vertical BM06B-GHS-TBT, mating GHR-06V-S; pins 1/2, 3/4 and 5/6 are separate channel pairs
J12	motor 1: 24 V, ground and the CAN pair	back	mates downward, out of the back face	1 = V24_MOTOR1, 2 = GND, 3 = CAN_H, 4 = CAN_L	JST PA BM04B-PASS-TFT, mating PAP-04V-S with SPHD-001T-P0.5 contacts; AWG22 for the power leads, CAN_H and CAN_L kept as a twisted pair
J13	motor 2: 24 V, ground and the CAN pair	back	mates downward, out of the back face	1 = V24_MOTOR2, 2 = GND, 3 = CAN_H, 4 = CAN_L	JST PA BM04B-PASS-TFT, mating PAP-04V-S with SPHD-001T-P0.5 contacts; AWG22 for the power leads, CAN_H and CAN_L kept as a twisted pair
J14	USB-C for programming and serial, alongside external 24 V	front	mates sideways, into the front-face edge	A1, A12, B1, B12 and the shell = GND; A4, A9, B4, B9 = USB_VBUS; A5 = USB_CC1; B5 = USB_CC2; A6, B6 = USB_DP_HOST; A7, B7 = USB_DM_HOST; A8, B8 unused	GCT USB4105-GF-A: 16 contacts plus four soldered through-hole shield stakes
J15	3.3 V UART service port	front	side-entry across the front face	1 = +3V3, 2 = GND, 3 = UART_TX, 4 = UART_RX	JST SH 4-way SM04B-SRSS-TB -- deliberately a different size from the GH ambient ports so a strip cable cannot be plugged in here
J16	a tap on the protected bus for a separately designed brake	front	side-entry across the front face	1 = V24_BUS, 2 = GND	Molex Pico-Lock 2053380002
J17	the physical ARM switch	front	vertical mating from the front face	1 = +3V3, 2 = ARM	JST PH 2-way B2B-PH-SM4-TB, mating PHR-2 with SPH-002T-P0.5S -- ships open, which means disarmed
J18	five spare GPIOs plus 3.3 V and ground	back	bare pads on the back face; no header is fitted	1 = +3V3, 2 = GND, 3 = GPIO19, 4 = GPIO20, 5 = GPIO21, 6 = GPIO22, 7 = GPIO23	no connector: 0.85 mm solder lands on 1.27 mm pitch

The parts list

One row is one exact part and footprint, so the same part number can appear on more than one row where the land pattern differs. Selecting a part on the board marks its row here without moving the page — use Show in parts list in the part's summary to actually jump to it. Going the other way, Locate all on a row highlights every place that part goes on the board.

Per board is the count for one PCB. For two boards doubles it, because PCBWay was asked to populate two of the five quoted boards — the other three would arrive bare. Bare pads, test points, mounting holes and the solder jumper are made with the PCB and are not purchased; they are listed separately below. No price or stock is claimed here, and every row of the source CSV carries the same status: quote only, exact source, quantity and process not confirmed.

Row	References	Per board	For two boards	Value / description	Part number	Package	Notes	Source
1	U1	1	2	ESP32-C6-WROOM-1-N8	ESP32-C6-WROOM-1-N8	castellated radio module with a ground pad under the body	3.3V supply; antenna keepout and peak-current/decoupling verification required	datasheet
2	R1 R2 R3 R4 R5 R6 R20 R21 R36 R40 R41 R502 R504 R506 R507 R508 R509 R512 R513 R518 R519 R520	22	44	10k	RC0603FR-0710KL	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
3	R526 R527 R528	3	6	910 ohm 1%	RC0603FR-07910RL	0603 chip resistor (1.6 x 0.8 mm)	Required with U5 Schmitt replacement; do not fit the old 10k on R526-R528.	datasheet
4	C1 C22 C42 C43 C508	5	10	1u / 1uF 25V X7R	C1608X7R1E105K080AB	0603 chip capacitor (1.6 x 0.8 mm)		datasheet
5	R7 R8 R301 R302 R303 R304 R305 R306 R307 R308 R309 R310 R311 R312 R313 R314 R315 R316 R317 R318 R319 R320 R321	23	46	2.2k	RC0603FR-072K2L	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
6	R9 R10 R11 R34 R35 R201 R202 R203 R204 R205 R206 R207 R208 R209 R210 R211 R212 R213 R214 R215 R216 R217 R218 R219 R220 R221 R510	27	54	100k	RC0603FR-07100KL	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
7	C2 C4 C5 C20 C21 C30 C31 C40 C41 C44 C45 C46 C500 C502 C503 C505 C509 C514 C515 C517 C518	21	42	100n / 100nF 100V X7R	GRM188R72A104KA35D	0603 chip capacitor (1.6 x 0.8 mm)		datasheet
8	C3 C510 C511 C512 C513	5	10	22uF 25V X7R	GRM32ER71E226KE15L	1210 chip capacitor (3.2 x 2.5 mm)	Nominal voltage/package checked; exact DC-bias effective capacitance and temperature/tolerance still required Update: Historical screen recorded with LIGHT v0.1 (c046202e), not rerun for this layout. The row's note still asks for DC-bias characterisation. For these two references that work was completed: both were changed to a 22 uF 25 V X7R in a 1210 package after a capacitance review, and the screens passed on characterised sample data plus an engineering reserve. The other references on this row were not part of that screen.	datasheet
9	S1 S2	2	4	RESET / BOOT	TL3305AF160QG	surface-mount tactile button	50mA12V; operating temperature -20 to70C; momentary reset/boot	datasheet
10	J17	1	2	ARM SWITCH	B2B-PH-SM4-TB(LF)(SN)	JST PH 2-way vertical socket	JST PH vertical SMD ARM connector, public PH catalogue p2 land pattern. Contact 1 3V3, contact 2 ARM.	datasheet
11	J15	1	2	UART DEBUG	SM04B-SRSS-TB(LF)(SN)	JST SH 4-way side-entry socket (1 mm pitch)	3.3V UART service; SH housing/crimp required; external adapter must not drive power pin1	datasheet
12	U5	1	2	74HCS08PWJ Schmitt-input quad AND	74HCS08PWJ	TSSOP-14 on 0.65 mm pitch	Audit candidate: Schmitt-input quad AND. Use with 910-ohm R526/R527/R528. 12NC 935691991118. See review control report for bounded drive and partial-power limitations.	datasheet
13	U6	1	2	SN74LVC1G04DBVR	SN74LVC1G04DBVR	SOT-23-5	3.3V inverter driving PCA OE; default-high OE pullup	datasheet
14	U4	1	2	TCAN1042HGVDRQ1	TCAN1042HGVDRQ1	SOIC-8	5V VCC/3.3V VIO; device bus-fault rating does not rate the complete terminated/protected port	datasheet
15	U16	1	2	NUP2105LT1G	NUP2105LT1G	SOT-23, three leads	24V working standoff; transient clamp only; no complete-port continuous high-voltage fault guarantee	datasheet
16	R22	1	2	120	RC0805FR-07120RL	0805 chip resistor (2.0 x 1.25 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity; termination0.125W, no24V across120ohm fault-survival claim	datasheet
17	J14	1	2	USB DATA /24V REQUIRED	USB4105-GF-A	USB-C receptacle: 16 contacts plus four through-hole shield stakes	USB data only,24V external power required; connector high-power headline does not rate this board	datasheet
18	R30 R31	2	4	5.1k	RC0603FR-075K1L	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
19	R32 R33	2	4	0	RC0603JR-070RL	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
20	U15	1	2	ESDS302	ESDS302DBVR	SOT-23-5	Ground-only dataTVS; pins1/3 NC; no rail clamp feed.	datasheet
21	D30	1	2	TPD1E10B06DYAR	TPD1E10B06DYAR	SOD-523 miniature diode	DYA SOD523 bidirectional 5.5V working limit; dedicated USB VBUS ESD	datasheet
22	Q30	1	2	MMBT3904	MMBT3904-7-F	SOT-23, three leads	SOT23 B1/E2/C3; USB sense only, no host power to logic supply	datasheet
23	U2 U3	2	4	PCA9685PW,118	PCA9685PW,118	TSSOP-28 on 0.65 mm pitch	3.3V TSSOP28; open-drain output with switchable bias; firmware duty polarity must follow external-transistor mode	datasheet
24	Q101 Q102 Q103 Q104 Q105 Q106 Q107 Q108 Q109 Q110 Q111 Q112 Q113 Q114 Q115 Q116 Q117 Q118 Q119 Q120 Q121	21	42	AO3422	AO3422	SOT-23, three leads	55V VDS;0.200ohm max at2.5Vgate25C; hot operating and short-circuit limits require verification	datasheet
25	R101 R102 R103 R104 R105 R106 R107 R108 R109 R110 R111 R112 R113 R114 R115 R116 R117 R118 R119 R120 R121	21	42	220	RC0603FR-07220RL	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
26	J8	1	2	ZONE 7	BM04B-GHS-TBT(LF)(SN)	JST GH 4-way vertical socket	JST GH vertical SMD. Public GH catalogue p2 land pattern. 1.25 mm pitch; preserve contact numbering when making harness.	datasheet
27	U17	1	2	TMUXHS221F	TMUXHS221FRSWR	UQFN-10, 1.4 x 1.8 mm on 0.4 mm pitch -- the finest-pitch part on the board	Host-VBUS interface supply only; default data parking; exact custom land pattern.	datasheet
28	R37 R38 R42	3	6	1k	RC0603FR-071KL	0603 chip resistor (1.6 x 0.8 mm)	1%0603 resistor; assembler must confirm sourcing.	datasheet
29	R39	1	2	33k	RC0603FR-0733KL	0603 chip resistor (1.6 x 0.8 mm)	1%0603 resistor; assembler must confirm sourcing.	datasheet
30	U18	1	2	TPS3808G33	TPS3808G33DBVR	SOT-23-6	3.07V supervisor; qualified reset timing and protected first-hardware checks remain.	datasheet
31	U19	1	2	SN74LVC1G97 AND Schmitt	SN74LVC1G97DBVR	SOT-23-6	Pin1=GND IN1, pin3=IN0; avoids slow-RC standard-CMOS input violation.	datasheet
32	U20	1	2	TMP112AIDRLR	TMP112AIDRLR	SOT-563, 1.6 x 1.2 mm -- the smallest logic package here	TMP112AIDRLR SOT-563, DRL pin map. 3.3 V I2C at 0x48; ADD0 to GND, unused ALERT explicitly NC. Local PCB temperature only; no extra I2C pullups.	datasheet
33	U12	1	2	24V input eFuse / 4.5A nominal	TPS26630RGER	VQFN-24, 4 x 4 mm on 0.5 mm pitch, with a thermal pad		datasheet
34	Q500	1	2	100V reverse blocking MOSFET	CSD19537Q3	VSON-8 power package with a large exposed drain		datasheet
35	Q501	1	2	fast reverse gate pull-down	2N7002BK,215	SOT-23, three leads		datasheet
36	D500	1	2	SMBJ33CA 33V bidirectional TVS	SMBJ33CA	SMB surface-mount diode		datasheet
37	F1	1	2	6.3A backup fuse	045106.3MRL	surface-mount fuse clips		datasheet
38	F2 F3	2	4	1A motor branch fuse	0451001.MRL	Nano2 surface-mount cartridge fuse		datasheet
39	F4 F5 F6 F7 F8 F9 F10	7	14	0.75A ambient zone fuse	0451.750MRL	Nano2 surface-mount cartridge fuse		datasheet
40	F11	1	2	0.5A logic branch fuse	0451.500MRL	Nano2 surface-mount cartridge fuse		datasheet
41	R500	1	2	4.02k	RC0603FR-074K02L	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
42	R501	1	2	140k	RC0603FR-07140KL	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
43	R503 R517	2	4	210k	RC0603FR-07210KL	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
44	R505	1	2	165k	RC0603FR-07165KL	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
45	C501	1	2	1uF 100V X7R	C3216X7R2A105K160AA	1206 chip capacitor (3.2 x 1.6 mm)		datasheet
46	C504	1	2	1000uF 50V low ESR	AFK108M50P44T-F	16 mm can electrolytic on provisional engineering-derived lands	1000uF50V caseP; factory controlled final installation after normal two-sided reflows; no stencil paste; provisional lands need approval;230C peak5s, >=200C20s, one reflow limit; confirm assembler process; Assembler process acknowledgement required	datasheet
47	U10	1	2	24V to 5V 1A buck	LMR36510ADDAR	SO PowerPAD-8: eight leads plus a thermal pad with eight vias under the body	0.125mm stencil basis; EP mask/paste 2.71x3.40mm, copper 2.95x4.90mm. Four thermal holes under paste require declared factory via treatment; no silent stencil-thickness change.	datasheet
48	L500	1	2	22uH 2.5A RMS 5.5A sat	SRP7050TA-220M	7 x 7 mm shielded power inductor		datasheet
49	C506 C519 C520 C521 C522 C523 C524	7	14	10uF 50V X7R	GRM32ER71H106KA12L	1210 chip capacitor (3.2 x 2.5 mm)	Nominal voltage/package checked; exact DC-bias effective capacitance and temperature/tolerance still required	datasheet
50	C507	1	2	220nF 50V X7R	C2012X7R1H224K125AA	0805 chip capacitor (2.0 x 1.25 mm)		datasheet
51	R511	1	2	24.9k	RC0603FR-0724K9L	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
52	U11	1	2	5V to 3.3V 1A fixed buck	TPS62162DSGR	WSON-8, 2 x 2 mm, with a thermal pad		datasheet
53	L501	1	2	2.2uH 2.9A RMS 3A sat	SRN4018-2R2M	4 x 4 mm shielded power inductor		datasheet
54	U13	1	2	switched ambient gate bias	TPS22919DCKR	SC-70-6		datasheet
55	R514	1	2	4.7k	RC0603FR-074K7L	0603 chip resistor (1.6 x 0.8 mm)	1%0603 resistor; assembler must confirm sourcing.	datasheet
56	U14	1	2	spot branch gated eFuse 0.494A nominal	TPS26600PWPR	HTSSOP-16 with a thermal pad and six vias under the body		datasheet
57	R515	1	2	24.3k	RC0603FR-0724K3L	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
58	R516	1	2	402k	RC0603FR-07402KL	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
59	R521	1	2	47k	RC0603FR-0747KL	0603 chip resistor (1.6 x 0.8 mm)	0.1W0603 or0.125W0805 at70C; exact value/code checked; assembler must confirm available quantity	datasheet
60	C516	1	2	47nF 50V X7R	C1608X7R1H473K080AA	0603 chip capacitor (1.6 x 0.8 mm)		datasheet
61	D501 D502 D503 D504	4	8	60V output negative transient Schottky / 60V 1A flyback Schottky	B160-13-F	SMA surface-mount diode		datasheet
62	U7 U8 U9	3	6	333mA spotlight CC driver	AL8860WT-7	TSOT-23-5	TSOT25 exactWT code;0.300ohm333mA nominal;220uH; local TVS/cutoff included; actual emitter and thermal limits pending	datasheet
63	R523 R524 R525	3	6	0.300ohm 1% 0.125W	ERJ-6RQFR30V	0805 chip resistor (2.0 x 1.25 mm)		datasheet
64	L502 L503 L504	3	6	220uH +/-20%, .6A RMS .7A saturation	SRN6045-221M	6 x 6 mm shielded power inductor	220uH,0.6A RMS,0.7A saturation at30%drop,1.18ohm max;250C maxreflow; hot ripple/thermal test pending	datasheet
65	D505	1	2	60V 5A output negative transient Schottky	B560C-13-F	SMC surface-mount diode		datasheet
66	U500 U501	2	4	27V flat-clamp transient protector	TVS2700DRVR	WSON-6, 2 x 2 mm, with a thermal pad	27V standoff; specified pulse-clamp35Vmax;12mA DC breakdown absolute limit; not continuous regeneration brake	datasheet
67	J1	1	2	24V INPUT	1771091	Phoenix PTSM top-entry spring terminal	Phoenix 1771091: upward SMD spring terminal; 6 A IEC rating, 0.5 mm2 / AWG20 PSU leads recommended, 6 mm strip; harness strain relief required. Exact availability and solder process require factory confirmation. Update: This terminal takes stripped wire directly; there is no mating plug to order.	datasheet
68	J16	1	2	24V INPUT / BRAKE / BUS	2053380002	Molex Pico-Lock 2-way socket	2-circuit input/brake;6.5A at20AWG fully loaded under specified rise; thermal/harness limits apply	datasheet
69	J12 J13	2	4	MOTOR 1	BM04B-PASS-TFT(LF)(SN)	JST PA 4-way vertical socket (2 mm pitch)	JST PA vertical SMD, no boss, TFT pickup packaging. Public PA drawing pp4/11; custom land geometry reviewed. 3 A with AWG22 rating; initial motor supply envelope 0.75 A each. Confirm mating housing/crimps and contact-1 orientation.	datasheet
70	J9	1	2	SPOTLIGHT 3 PAIRS	BM06B-GHS-TBT(LF)(SN)	JST GH six-contact vertical socket	Six independent contacts: 1/2 SPOT1 +/-, 3/4 SPOT2 +/-, 5/6 SPOT3 +/-. No LED return or positive is merged. Vertical mating axis on underside; match GHR-06V-S housing and SSHL-002T-P0.2 contacts, AWG26 for rated 1 A. Keep wire service-loop strain off connector and flex pads.	datasheet
71	J2	1	2	2005280300 / 6-ZONE FLEX	2005280300	Molex 30-contact 1 mm locking flex socket	30 contacts; 1 mm pitch; bottom contact / Front Flip. Do not wash. Maximum two reflows; connector faces upward in second reflow. Preserve actuator access. Mate B-side gold flex fingers, total insertion thickness 0.30 +/-0.05 mm.	datasheet

Board features, which are not purchased parts

Feature	What it is	Why it is not in the parts list
H1	3.2 mm unplated M3 hole	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
H2	3.2 mm unplated M3 hole	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
H3	3.2 mm unplated M3 hole	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
H4	3.2 mm unplated M3 hole	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
J18	seven bare solder lands on 1.27 mm pitch	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
JP1	two-pad solder jumper, open as manufactured	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP1	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP2	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP3	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP4	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP5	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP6	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP7	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP8	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP9	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP10	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP11	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP12	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP13	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP14	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.
TP15	1 mm bare probe pad	Made with the PCB itself -- copper, a hole or bare pads -- so it is not a purchased package.

Bare PCB versus PCB assembly

A bare PCB is the board on its own: fibreglass, copper, mask and silkscreen, made from the fabrication outputs. A PCB assembly (PCBA) is that board with all the parts sourced, placed and soldered. They are quoted separately, priced separately and can be ordered separately — which is why "five boards, two assembled" is a coherent request rather than a contradiction.

The parts list on this page is the assembly side of that: what would be fitted to the two populated boards. The fabrication reference is the bare-board side.

What PCB assembly has to handle here — acknowledgement pending

These are factory process items, not hand-soldering tasks. Some inspection requests have been acknowledged, but the revised board still needs an accepted process and stack:

• U10 and U14 have thermal pads with vias underneath, some directly beneath the paste. A qualified filling or capping process is required; ordinary mask tenting is not evidence of a sealed, solderable surface.
• C504, the 1000 µF can, sits on provisional engineering-derived lands with no paste apertures and tolerates one reflow at 230 °C peak for at most 5 s. It needs controlled final installation after ordinary two-sided reflow.
• J14's four shield stakes are plated through-hole slots that must be soldered and must not be filled or capped. Zero through-hole packages does not mean zero through-hole joints.
• U17 is a 0.4 mm-pitch UQFN, 1.4 × 1.8 mm. Its mask webs and stencil registration need review, and its lands must not be silently modified.
• J2 is a no-wash connector, with at most two reflows and the connector upward in the second pass. Its latch needs opening clearance; the upper tail needs the correct total insertion thickness.
• No substitution is pre-approved. Matching a value, voltage and footprint is not sufficient.

Hand soldering — optional rework only

Hand assembly is not the plan for these boards, and this design was never redesigned to be iron-only. If you are considering rework, these are the limits worth knowing: the board is two-sided with 0603 passives throughout; several parts have pads underneath the body that an iron cannot reach; U17 is 0.4 mm pitch; U20 is a 1.6 × 1.2 mm package. Suitable hot-air or reflow equipment changes what is feasible — a soldering iron alone does not.

The schematic — 20 sheets

The schematic says how the circuit is connected and why it works. It does not say where anything sits. Matching net labels mean those points are connected even when they appear on different sheets, and a tiny crossed mark is a deliberate no-connect, not a broken route.

Start with sheet 1, the hierarchy map: it has no parts of its own, and each box on it is one of the other 19 sheets. Selecting a part on the board offers its sheet.

The sheet browser needs JavaScript. Every sheet is linked in the table below, and the complete 19-page schematic PDF has the same pages in the same order.

Sheet	Title	Parts	View	Native file	What is on it
1	Integrated lighting controller	0	open the drawing	engineered-lighting-rev-a.kicad_sch	The hierarchy map. It has no components of its own -- each box is one of the other 19 sheets, labelled with its file name.
2	Controller	23	open the drawing	controller.kicad_sch	The controller: the radio module, its reset and boot circuitry, the UART service port and the ARM input.
3	Power Sequence	5	open the drawing	power_sequence.kicad_sch	The power sequence: the supervisor and the gate that decides when lighting is allowed.
4	Can	11	open the drawing	can.kicad_sch	CAN: the transceiver, its protection, the termination option and both motor connectors.
5	Usb	19	open the drawing	usb.kicad_sch	The USB-C island: connector, protection, presence sensing and the data multiplexer.
6	Pwm	6	open the drawing	pwm.kicad_sch	The two PWM expanders and the I2C bus that reaches them.
7	Zone 1	12	open the drawing	zone_1.kicad_sch	Ambient zone 1 low-side W/N/C switches; outputs now reach the shared J2 interface on sheet 20.
8	Zone 2	12	open the drawing	zone_2.kicad_sch	Ambient zone 2 low-side W/N/C switches; outputs now reach the shared J2 interface on sheet 20.
9	Zone 3	12	open the drawing	zone_3.kicad_sch	Ambient zone 3 low-side W/N/C switches; outputs now reach the shared J2 interface on sheet 20.
10	Zone 4	12	open the drawing	zone_4.kicad_sch	Ambient zone 4 low-side W/N/C switches; outputs now reach the shared J2 interface on sheet 20.
11	Zone 5	12	open the drawing	zone_5.kicad_sch	Ambient zone 5 low-side W/N/C switches; outputs now reach the shared J2 interface on sheet 20.
12	Zone 6	12	open the drawing	zone_6.kicad_sch	Ambient zone 6 low-side W/N/C switches; outputs now reach the shared J2 interface on sheet 20.
13	Zone 7	13	open the drawing	zone_7.kicad_sch	Ambient zone 7 -- the bottom ring. Its connector mates downward from the back face.
14	Test	12	open the drawing	test.kicad_sch	The test points: every pad bring-up expects to probe.
15	Power 1	31	open the drawing	power_1.kicad_sch	Power, part 1: the input protection chain and the branch fuses.
16	Power 2	24	open the drawing	power_2.kicad_sch	Power, part 2: the 24 V input terminal and the two switching converters.
17	Spot 1	30	open the drawing	spot_1.kicad_sch	Spotlight, part 1: the gated supply and the three constant-current driver cells.
18	Spot 2	5	open the drawing	spot_2.kicad_sch	Spotlight, part 2: the driver outputs and their connectors.
19	Monitor Expansion	10	open the drawing	monitor_expansion.kicad_sch	Monitoring and expansion: the temperature sensor, the expansion pads, the boot-strap probes and the mounting holes.
20	Central six-zone LED flex interface	1	open the drawing	central_led_interface.kicad_sch	One locking 30-contact interface for the six radial zones; paired positive contacts keep each fused zone separate.

Why the drawings still say “Rev A”

The project keeps the original engineered-lighting-rev-a file name. Most inherited sheets still have their 6 September Rev: A draft title blocks; the new central interface sheet says LIGHT v0.2 candidate, dated 8 September. The full hash in provenance, rather than a retained drawing title, identifies this snapshot.

All 262 features, by circuit family

Every physical feature on the board, grouped by what it does. This index works without JavaScript, and it is what the search box searches.

Ambient channel switch 21

Reference	What it is	Value	Part number	Face	Sheet	Parts list
Q101	Zone 1 warm channel switch	AO3422	AO3422	front	7	row 24
Q102	Zone 1 neutral channel switch	AO3422	AO3422	front	7	row 24
Q103	Zone 1 cool channel switch	AO3422	AO3422	front	7	row 24
Q104	Zone 2 warm channel switch	AO3422	AO3422	front	8	row 24
Q105	Zone 2 neutral channel switch	AO3422	AO3422	front	8	row 24
Q106	Zone 2 cool channel switch	AO3422	AO3422	front	8	row 24
Q107	Zone 3 warm channel switch	AO3422	AO3422	front	9	row 24
Q108	Zone 3 neutral channel switch	AO3422	AO3422	front	9	row 24
Q109	Zone 3 cool channel switch	AO3422	AO3422	front	9	row 24
Q110	Zone 4 warm channel switch	AO3422	AO3422	front	10	row 24
Q111	Zone 4 neutral channel switch	AO3422	AO3422	front	10	row 24
Q112	Zone 4 cool channel switch	AO3422	AO3422	front	10	row 24
Q113	Zone 5 warm channel switch	AO3422	AO3422	front	11	row 24
Q114	Zone 5 neutral channel switch	AO3422	AO3422	front	11	row 24
Q115	Zone 5 cool channel switch	AO3422	AO3422	front	11	row 24
Q116	Zone 6 warm channel switch	AO3422	AO3422	front	12	row 24
Q117	Zone 6 neutral channel switch	AO3422	AO3422	front	12	row 24
Q118	Zone 6 cool channel switch	AO3422	AO3422	front	12	row 24
Q119	Zone 7 warm channel switch	AO3422	AO3422	front	13	row 24
Q120	Zone 7 neutral channel switch	AO3422	AO3422	front	13	row 24
Q121	Zone 7 cool channel switch	AO3422	AO3422	front	13	row 24

Ambient gate pull-down 21

Reference	What it is	Value	Part number	Face	Sheet	Parts list
R201	Zone 1 warm gate pull-down	100k	RC0603FR-07100KL	back	7	row 6
R202	Zone 1 neutral gate pull-down	100k	RC0603FR-07100KL	back	7	row 6
R203	Zone 1 cool gate pull-down	100k	RC0603FR-07100KL	front	7	row 6
R204	Zone 2 warm gate pull-down	100k	RC0603FR-07100KL	back	8	row 6
R205	Zone 2 neutral gate pull-down	100k	RC0603FR-07100KL	back	8	row 6
R206	Zone 2 cool gate pull-down	100k	RC0603FR-07100KL	front	8	row 6
R207	Zone 3 warm gate pull-down	100k	RC0603FR-07100KL	back	9	row 6
R208	Zone 3 neutral gate pull-down	100k	RC0603FR-07100KL	back	9	row 6
R209	Zone 3 cool gate pull-down	100k	RC0603FR-07100KL	back	9	row 6
R210	Zone 4 warm gate pull-down	100k	RC0603FR-07100KL	back	10	row 6
R211	Zone 4 neutral gate pull-down	100k	RC0603FR-07100KL	back	10	row 6
R212	Zone 4 cool gate pull-down	100k	RC0603FR-07100KL	front	10	row 6
R213	Zone 5 warm gate pull-down	100k	RC0603FR-07100KL	back	11	row 6
R214	Zone 5 neutral gate pull-down	100k	RC0603FR-07100KL	back	11	row 6
R215	Zone 5 cool gate pull-down	100k	RC0603FR-07100KL	back	11	row 6
R216	Zone 6 warm gate pull-down	100k	RC0603FR-07100KL	back	12	row 6
R217	Zone 6 neutral gate pull-down	100k	RC0603FR-07100KL	back	12	row 6
R218	Zone 6 cool gate pull-down	100k	RC0603FR-07100KL	back	12	row 6
R219	Zone 7 warm gate pull-down	100k	RC0603FR-07100KL	back	13	row 6
R220	Zone 7 neutral gate pull-down	100k	RC0603FR-07100KL	back	13	row 6
R221	Zone 7 cool gate pull-down	100k	RC0603FR-07100KL	back	13	row 6

Ambient gate pull-up 21

Reference	What it is	Value	Part number	Face	Sheet	Parts list
R301	Zone 1 warm gate pull-up	2.2k	RC0603FR-072K2L	back	7	row 5
R302	Zone 1 neutral gate pull-up	2.2k	RC0603FR-072K2L	back	7	row 5
R303	Zone 1 cool gate pull-up	2.2k	RC0603FR-072K2L	back	7	row 5
R304	Zone 2 warm gate pull-up	2.2k	RC0603FR-072K2L	back	8	row 5
R305	Zone 2 neutral gate pull-up	2.2k	RC0603FR-072K2L	back	8	row 5
R306	Zone 2 cool gate pull-up	2.2k	RC0603FR-072K2L	back	8	row 5
R307	Zone 3 warm gate pull-up	2.2k	RC0603FR-072K2L	back	9	row 5
R308	Zone 3 neutral gate pull-up	2.2k	RC0603FR-072K2L	back	9	row 5
R309	Zone 3 cool gate pull-up	2.2k	RC0603FR-072K2L	back	9	row 5
R310	Zone 4 warm gate pull-up	2.2k	RC0603FR-072K2L	back	10	row 5
R311	Zone 4 neutral gate pull-up	2.2k	RC0603FR-072K2L	back	10	row 5
R312	Zone 4 cool gate pull-up	2.2k	RC0603FR-072K2L	back	10	row 5
R313	Zone 5 warm gate pull-up	2.2k	RC0603FR-072K2L	back	11	row 5
R314	Zone 5 neutral gate pull-up	2.2k	RC0603FR-072K2L	back	11	row 5
R315	Zone 5 cool gate pull-up	2.2k	RC0603FR-072K2L	back	11	row 5
R316	Zone 6 warm gate pull-up	2.2k	RC0603FR-072K2L	back	12	row 5
R317	Zone 6 neutral gate pull-up	2.2k	RC0603FR-072K2L	back	12	row 5
R318	Zone 6 cool gate pull-up	2.2k	RC0603FR-072K2L	back	12	row 5
R319	Zone 7 warm gate pull-up	2.2k	RC0603FR-072K2L	back	13	row 5
R320	Zone 7 neutral gate pull-up	2.2k	RC0603FR-072K2L	back	13	row 5
R321	Zone 7 cool gate pull-up	2.2k	RC0603FR-072K2L	back	13	row 5

Ambient gate series resistor 21

Reference	What it is	Value	Part number	Face	Sheet	Parts list
R101	Zone 1 warm gate resistor	220	RC0603FR-07220RL	front	7	row 25
R102	Zone 1 neutral gate resistor	220	RC0603FR-07220RL	front	7	row 25
R103	Zone 1 cool gate resistor	220	RC0603FR-07220RL	front	7	row 25
R104	Zone 2 warm gate resistor	220	RC0603FR-07220RL	front	8	row 25
R105	Zone 2 neutral gate resistor	220	RC0603FR-07220RL	front	8	row 25
R106	Zone 2 cool gate resistor	220	RC0603FR-07220RL	front	8	row 25
R107	Zone 3 warm gate resistor	220	RC0603FR-07220RL	front	9	row 25
R108	Zone 3 neutral gate resistor	220	RC0603FR-07220RL	front	9	row 25
R109	Zone 3 cool gate resistor	220	RC0603FR-07220RL	front	9	row 25
R110	Zone 4 warm gate resistor	220	RC0603FR-07220RL	front	10	row 25
R111	Zone 4 neutral gate resistor	220	RC0603FR-07220RL	front	10	row 25
R112	Zone 4 cool gate resistor	220	RC0603FR-07220RL	front	10	row 25
R113	Zone 5 warm gate resistor	220	RC0603FR-07220RL	front	11	row 25
R114	Zone 5 neutral gate resistor	220	RC0603FR-07220RL	front	11	row 25
R115	Zone 5 cool gate resistor	220	RC0603FR-07220RL	front	11	row 25
R116	Zone 6 warm gate resistor	220	RC0603FR-07220RL	front	12	row 25
R117	Zone 6 neutral gate resistor	220	RC0603FR-07220RL	front	12	row 25
R118	Zone 6 cool gate resistor	220	RC0603FR-07220RL	front	12	row 25
R119	Zone 7 warm gate resistor	220	RC0603FR-07220RL	front	13	row 25
R120	Zone 7 neutral gate resistor	220	RC0603FR-07220RL	front	13	row 25
R121	Zone 7 cool gate resistor	220	RC0603FR-07220RL	front	13	row 25

Ambient zone connector 2

Reference	What it is	Value	Part number	Face	Sheet	Parts list
J2	Six-zone locking flex interface	2005280300 / 6-ZONE FLEX	2005280300	front	20	row 71
J8	Ambient zone 7 connector	ZONE 7	BM04B-GHS-TBT(LF)(SN)	back	13	row 26

Ambient zone fuse 7

Reference	What it is	Value	Part number	Face	Sheet	Parts list
F4	Ambient zone 1 fuse	0.75A ambient zone fuse	0451.750MRL	front	15	row 39
F5	Ambient zone 2 fuse	0.75A ambient zone fuse	0451.750MRL	front	15	row 39
F6	Ambient zone 3 fuse	0.75A ambient zone fuse	0451.750MRL	front	15	row 39
F7	Ambient zone 4 fuse	0.75A ambient zone fuse	0451.750MRL	front	15	row 39
F8	Ambient zone 5 fuse	0.75A ambient zone fuse	0451.750MRL	front	15	row 39
F9	Ambient zone 6 fuse	0.75A ambient zone fuse	0451.750MRL	front	15	row 39
F10	Ambient zone 7 fuse	0.75A ambient zone fuse	0451.750MRL	front	15	row 39

Boot-strap probe pad 3

Reference	What it is	Value	Part number	Face	Sheet	Parts list
TP13	Boot-strap probe pad (GPIO4_STRAP)	GPIO4 STRAP	PCB FEATURE	front	19	PCB feature
TP14	Boot-strap probe pad (GPIO5_STRAP)	GPIO5 STRAP	PCB FEATURE	front	19	PCB feature
TP15	Boot-strap probe pad (GPIO15_STRAP)	GPIO15 STRAP	PCB FEATURE	front	19	PCB feature

Bulk reservoir capacitor 9

Reference	What it is	Value	Part number	Face	Sheet	Parts list
C1	MCU_EN reservoir	1u	C1608X7R1E105K080AB	back	2	row 4
C3	+3V3 reservoir	22uF 25V X7R	GRM32ER71E226KE15L	back	2	row 8
C501	VIN24_FUSED reservoir	1uF 100V X7R	C3216X7R2A105K160AA	back	15	row 45
C506	V24_LOGIC reservoir	10uF 50V X7R	GRM32ER71H106KA12L	back	16	row 49
C508	BUCK5_VCC reservoir	1uF 25V X7R	C1608X7R1E105K080AB	back	16	row 4
C510	+5V reservoir	22uF 25V X7R	GRM32ER71E226KE15L	back	16	row 8
C511	+5V reservoir	22uF 25V X7R	GRM32ER71E226KE15L	back	16	row 8
C512	+5V reservoir	22uF 25V X7R	GRM32ER71E226KE15L	back	16	row 8
C513	+3V3 reservoir	22uF 25V X7R	GRM32ER71E226KE15L	back	16	row 8

Decoupling capacitor 23

Reference	What it is	Value	Part number	Face	Sheet	Parts list
C2	U1 decoupling capacitor	100n	GRM188R72A104KA35D	front	2	row 7
C4	U5 decoupling capacitor	100n	GRM188R72A104KA35D	front	2	row 7
C5	U6 decoupling capacitor	100n	GRM188R72A104KA35D	front	2	row 7
C20	U4 decoupling capacitor	100n	GRM188R72A104KA35D	back	4	row 7
C21	U4 decoupling capacitor	100n	GRM188R72A104KA35D	front	4	row 7
C22	U4 decoupling capacitor	1u	C1608X7R1E105K080AB	front	4	row 4
C30	J14 decoupling capacitor	100n	GRM188R72A104KA35D	front	5	row 7
C31	U17 decoupling capacitor	100n	GRM188R72A104KA35D	back	5	row 7
C40	U2 decoupling capacitor	100n	GRM188R72A104KA35D	front	6	row 7
C41	U3 decoupling capacitor	100n	GRM188R72A104KA35D	front	6	row 7
C42	U2 decoupling capacitor	1u	C1608X7R1E105K080AB	front	6	row 4
C43	U3 decoupling capacitor	1u	C1608X7R1E105K080AB	front	6	row 4
C44	U18 decoupling capacitor	100n	GRM188R72A104KA35D	back	3	row 7
C45	U19 decoupling capacitor	100n	GRM188R72A104KA35D	back	3	row 7
C46	U20 decoupling capacitor	100n	GRM188R72A104KA35D	back	19	row 7
C500	F1 decoupling capacitor	100nF 100V X7R	GRM188R72A104KA35D	back	15	row 7
C502	Q500 decoupling capacitor	100nF 100V X7R	GRM188R72A104KA35D	back	15	row 7
C505	U12 decoupling capacitor	100nF 100V X7R	GRM188R72A104KA35D	back	15	row 7
C507	U10 decoupling capacitor	220nF 50V X7R	C2012X7R1H224K125AA	back	16	row 50
C514	U13 decoupling capacitor	100nF 100V X7R	GRM188R72A104KA35D	front	16	row 7
C515	U13 decoupling capacitor	100nF 100V X7R	GRM188R72A104KA35D	front	16	row 7
C517	U14 decoupling capacitor	100nF 100V X7R	GRM188R72A104KA35D	back	17	row 7
C518	U14 decoupling capacitor	100nF 100V X7R	GRM188R72A104KA35D	back	17	row 7

Expansion solder pads 1

Reference	What it is	Value	Part number	Face	Sheet	Parts list
J18	Expansion solder pads	GPIO EXPANSION 3V3	PCB FEATURE	back	19	PCB feature

Input backup fuse 1

Reference	What it is	Value	Part number	Face	Sheet	Parts list
F1	Input backup fuse	6.3A backup fuse	045106.3MRL	front	15	row 37

Logic branch fuse 1

Reference	What it is	Value	Part number	Face	Sheet	Parts list
F11	Logic branch fuse	0.5A logic branch fuse	0451.500MRL	back	15	row 40

Motor branch fuse 2

Reference	What it is	Value	Part number	Face	Sheet	Parts list
F2	Motor 1 fuse	1A motor branch fuse	0451001.MRL	front	15	row 38
F3	Motor 2 fuse	1A motor branch fuse	0451001.MRL	front	15	row 38

Mounting hole 4

Reference	What it is	Value	Part number	Face	Sheet	Parts list
H1	M3 mounting hole	M3 / 3.2mm NPTH	PCB FEATURE	front	19	PCB feature
H2	M3 mounting hole	M3 / 3.2mm NPTH	PCB FEATURE	front	19	PCB feature
H3	M3 mounting hole	M3 / 3.2mm NPTH	PCB FEATURE	front	19	PCB feature
H4	M3 mounting hole	M3 / 3.2mm NPTH	PCB FEATURE	front	19	PCB feature

Named part 41

Reference	What it is	Value	Part number	Face	Sheet	Parts list
C503	eFuse output ramp capacitor	100nF 100V X7R	GRM188R72A104KA35D	back	15	row 7
C504	Bulk capacitor on the protected bus	1000uF 50V low ESR	AFK108M50P44T-F	back	15	row 46
C509	Bootstrap capacitor	100nF 100V X7R	GRM188R72A104KA35D	back	16	row 7
C516	Spotlight eFuse ramp capacitor	47nF 50V X7R	C1608X7R1H473K080AA	back	17	row 60
D30	USB bus-voltage protection	TPD1E10B06DYAR	TPD1E10B06DYAR	front	5	row 21
D500	Input transient suppressor	SMBJ33CA 33V bidirectional TVS	SMBJ33CA	back	15	row 36
D501	Spotlight rail negative-transient diode	60V output negative transient Schottky	B160-13-F	back	17	row 61
D505	Bus negative-transient diode	60V 5A output negative transient Schottky	B560C-13-F	back	16	row 65
J1	24 V input terminal	24V INPUT	1771091	front	16	row 67
J12	Motor 1 connector	MOTOR 1	BM04B-PASS-TFT(LF)(SN)	back	4	row 69
J13	Motor 2 connector	MOTOR 2	BM04B-PASS-TFT(LF)(SN)	back	4	row 69
J14	USB-C connector	USB DATA /24V REQUIRED	USB4105-GF-A	front	5	row 17
J15	UART service port	UART DEBUG	SM04B-SRSS-TB(LF)(SN)	front	2	row 11
J16	Protected-bus service port	BRAKE / BUS	2053380002	front	16	row 68
J17	ARM switch connector	ARM SWITCH	B2B-PH-SM4-TB(LF)(SN)	front	2	row 10
L500	5 V converter inductor	22uH 2.5A RMS 5.5A sat	SRP7050TA-220M	back	16	row 48
L501	3.3 V converter inductor	2.2uH 2.9A RMS 3A sat	SRN4018-2R2M	back	16	row 53
Q30	USB presence sensor	MMBT3904	MMBT3904-7-F	front	5	row 22
Q500	Reverse-blocking transistor	100V reverse blocking MOSFET	CSD19537Q3	back	15	row 34
Q501	Reverse gate pull-down	fast reverse gate pull-down	2N7002BK,215	front	15	row 35
S1	RESET button	RESET	TL3305AF160QG	front	2	row 9
S2	BOOT button	BOOT	TL3305AF160QG	front	2	row 9
U1	ESP32-C6 radio module (the controller)	ESP32-C6-WROOM-1-N8	ESP32-C6-WROOM-1-N8	front	2	row 1
U2	PWM expander at address 0x40	PCA9685PW,118	PCA9685PW,118	front	6	row 23
U3	PWM expander at address 0x41	PCA9685PW,118	PCA9685PW,118	front	6	row 23
U4	CAN transceiver	TCAN1042HGVDRQ1	TCAN1042HGVDRQ1	front	4	row 14
U5	Schmitt-input spotlight permission gate	74HCS08PWJ	74HCS08PWJ	front	2	row 12
U6	Inverter for the expanders' output-enable	SN74LVC1G04DBVR	SN74LVC1G04DBVR	front	2	row 13
U10	24 V to 5 V converter	24V to 5V 1A buck	LMR36510ADDAR	back	16	row 47
U11	5 V to 3.3 V converter	5V to 3.3V 1A fixed buck	TPS62162DSGR	back	16	row 52
U12	24 V eFuse (the main protection chip)	24V input eFuse / 4.5A nominal	TPS26630RGER	back	15	row 33
U13	Gate-bias load switch	switched ambient gate bias	TPS22919DCKR	front	16	row 54
U14	Spotlight supply eFuse	spot branch gated eFuse 0.494A nominal	TPS26600PWPR	back	17	row 56
U15	USB data-line protection	ESDS302	ESDS302DBVR	front	5	row 20
U16	CAN bus transient clamp	NUP2105LT1G	NUP2105LT1G	front	4	row 15
U17	USB data multiplexer	TMUXHS221F	TMUXHS221FRSWR	front	5	row 27
U18	3.3 V supply supervisor	TPS3808G33	TPS3808G33DBVR	back	3	row 30
U19	Schmitt AND gate: the SAFE decision	SN74LVC1G97 AND Schmitt	SN74LVC1G97DBVR	back	3	row 31
U20	Board temperature sensor	TMP112AIDRLR	TMP112AIDRLR	back	19	row 32
U500	Flat clamp on the spotlight rail	27V flat-clamp transient protector	TVS2700DRVR	back	18	row 66
U501	Flat clamp on the protected bus	27V flat-clamp transient protector	TVS2700DRVR	back	16	row 66

Pull-down resistor 15

Reference	What it is	Value	Part number	Face	Sheet	Parts list
R4	LIGHT_ENABLE pull-down	10k	RC0603FR-0710KL	front	2	row 2
R5	ARM pull-down	10k	RC0603FR-0710KL	front	2	row 2
R9	SPOT1_PWM pull-down	100k	RC0603FR-07100KL	front	2	row 6
R10	SPOT2_PWM pull-down	100k	RC0603FR-07100KL	back	2	row 6
R11	SPOT3_PWM pull-down	100k	RC0603FR-07100KL	front	2	row 6
R21	CAN_STB pull-down	10k	RC0603FR-0710KL	front	4	row 2
R30	USB_CC1 pull-down	5.1k	RC0603FR-075K1L	front	5	row 18
R31	USB_CC2 pull-down	5.1k	RC0603FR-075K1L	front	5	row 18
R37	USB_DP_PARK pull-down	1k	RC0603FR-071KL	back	5	row 28
R38	USB_DM_PARK pull-down	1k	RC0603FR-071KL	front	5	row 28
R40	USB_VBUS pull-down	10k	RC0603FR-0710KL	back	5	row 2
R507	EFUSE_IMON pull-down	10k	RC0603FR-0710KL	back	15	row 2
R514	LIGHT_ENABLE_SAFE pull-down	4.7k	RC0603FR-074K7L	back	16	row 55
R519	SPOT_EFUSE_IMON pull-down	10k	RC0603FR-0710KL	back	17	row 2
R521	V24_SPOT pull-down	47k	RC0603FR-0747KL	back	17	row 59

Pull-up resistor 13

Reference	What it is	Value	Part number	Face	Sheet	Parts list
R1	MCU_EN pull-up	10k	RC0603FR-0710KL	front	2	row 2
R2	BOOT_GPIO9 pull-up	10k	RC0603FR-0710KL	front	2	row 2
R3	BOOT_GPIO8 pull-up	10k	RC0603FR-0710KL	back	2	row 2
R6	PCA_OE pull-up	10k	RC0603FR-0710KL	front	2	row 2
R7	I2C_SDA pull-up	2.2k	RC0603FR-072K2L	front	2	row 5
R8	I2C_SCL pull-up	2.2k	RC0603FR-072K2L	front	2	row 5
R20	CAN_TX pull-up	10k	RC0603FR-0710KL	front	4	row 2
R36	USB_PRESENT_N pull-up	10k	RC0603FR-0710KL	front	5	row 2
R508	EFUSE_FLT_N pull-up	10k	RC0603FR-0710KL	back	15	row 2
R509	EFUSE_PGOOD pull-up	10k	RC0603FR-0710KL	back	15	row 2
R512	BUCK5_PGOOD pull-up	10k	RC0603FR-0710KL	back	16	row 2
R513	BUCK3_PGOOD pull-up	10k	RC0603FR-0710KL	back	16	row 2
R520	SPOT_EFUSE_FLT_N pull-up	10k	RC0603FR-0710KL	back	17	row 2

Resistive divider leg 14

Reference	What it is	Value	Part number	Face	Sheet	Parts list
R34	Divider leg on USB_SENSE_BASE	100k	RC0603FR-07100KL	front	5	row 6
R35	Divider leg on USB_SENSE_BASE	100k	RC0603FR-07100KL	front	5	row 6
R39	Divider leg on USB_READY_SELECT	33k	RC0603FR-0733KL	back	5	row 29
R41	Divider leg on USB_READY_SELECT	10k	RC0603FR-0710KL	front	5	row 2
R501	Divider leg on EFUSE_UVLO	140k	RC0603FR-07140KL	back	15	row 42
R502	Divider leg on EFUSE_UVLO	10k	RC0603FR-0710KL	back	15	row 2
R503	Divider leg on EFUSE_OVP	210k	RC0603FR-07210KL	back	15	row 43
R504	Divider leg on EFUSE_OVP	10k	RC0603FR-0710KL	back	15	row 2
R505	Divider leg on EFUSE_PGTH	165k	RC0603FR-07165KL	back	15	row 44
R506	Divider leg on EFUSE_PGTH	10k	RC0603FR-0710KL	back	15	row 2
R510	Divider leg on BUCK5_FB	100k	RC0603FR-07100KL	back	16	row 6
R511	Divider leg on BUCK5_FB	24.9k	RC0603FR-0724K9L	back	16	row 51
R517	Divider leg on SPOT_EFUSE_OVP	210k	RC0603FR-07210KL	back	17	row 43
R518	Divider leg on SPOT_EFUSE_OVP	10k	RC0603FR-0710KL	back	17	row 2

Setting resistor 7

Reference	What it is	Value	Part number	Face	Sheet	Parts list
R22	Setting resistor on CAN_TERM	120	RC0805FR-07120RL	front	4	row 16
R32	Setting resistor on USB_DM_MCU	0	RC0603JR-070RL	front	5	row 19
R33	Setting resistor on USB_DP_MCU	0	RC0603JR-070RL	front	5	row 19
R42	Setting resistor on MCU_EN	1k	RC0603FR-071KL	back	3	row 28
R500	Setting resistor on EFUSE_ILIM	4.02k	RC0603FR-074K02L	back	15	row 41
R515	Setting resistor on SPOT_EFUSE_ILIM	24.3k	RC0603FR-0724K3L	back	17	row 57
R516	Setting resistor on SPOT_EFUSE_MODE	402k	RC0603FR-07402KL	back	17	row 58

Solder jumper 1

Reference	What it is	Value	Part number	Face	Sheet	Parts list
JP1	CAN termination jumper	CAN TERMINATION		front	4	PCB feature

Spotlight CTRL pull-down 3

Reference	What it is	Value	Part number	Face	Sheet	Parts list
R526	Spotlight 1 CTRL pull-down	910	RC0603FR-07910RL	back	17	row 3
R527	Spotlight 2 CTRL pull-down	910	RC0603FR-07910RL	back	17	row 3
R528	Spotlight 3 CTRL pull-down	910	RC0603FR-07910RL	back	17	row 3

Spotlight catch diode 3

Reference	What it is	Value	Part number	Face	Sheet	Parts list
D502	Spotlight 1 catch diode	60V 1A flyback Schottky	B160-13-F	back	17	row 61
D503	Spotlight 2 catch diode	60V 1A flyback Schottky	B160-13-F	back	17	row 61
D504	Spotlight 3 catch diode	60V 1A flyback Schottky	B160-13-F	back	18	row 61

Spotlight current-sense resistor 3

Reference	What it is	Value	Part number	Face	Sheet	Parts list
R523	Spotlight 1 current sense	0.300ohm 1% 0.125W	ERJ-6RQFR30V	back	17	row 63
R524	Spotlight 2 current sense	0.300ohm 1% 0.125W	ERJ-6RQFR30V	back	17	row 63
R525	Spotlight 3 current sense	0.300ohm 1% 0.125W	ERJ-6RQFR30V	back	17	row 63

Spotlight driver 3

Reference	What it is	Value	Part number	Face	Sheet	Parts list
U7	Spotlight 1 driver	333mA spotlight CC driver	AL8860WT-7	back	17	row 62
U8	Spotlight 2 driver	333mA spotlight CC driver	AL8860WT-7	back	17	row 62
U9	Spotlight 3 driver	333mA spotlight CC driver	AL8860WT-7	back	17	row 62

Spotlight driver input capacitor 6

Reference	What it is	Value	Part number	Face	Sheet	Parts list
C519	Spotlight 1 input capacitor	10uF 50V X7R	GRM32ER71H106KA12L	back	17	row 49
C520	Spotlight 1 input capacitor	10uF 50V X7R	GRM32ER71H106KA12L	back	17	row 49
C521	Spotlight 2 input capacitor	10uF 50V X7R	GRM32ER71H106KA12L	back	17	row 49
C522	Spotlight 2 input capacitor	10uF 50V X7R	GRM32ER71H106KA12L	back	17	row 49
C523	Spotlight 3 input capacitor	10uF 50V X7R	GRM32ER71H106KA12L	back	18	row 49
C524	Spotlight 3 input capacitor	10uF 50V X7R	GRM32ER71H106KA12L	back	18	row 49

Spotlight inductor 3

Reference	What it is	Value	Part number	Face	Sheet	Parts list
L502	Spotlight 1 inductor	220uH +/-20%, .6A RMS .7A saturation	SRN6045-221M	back	17	row 64
L503	Spotlight 2 inductor	220uH +/-20%, .6A RMS .7A saturation	SRN6045-221M	back	17	row 64
L504	Spotlight 3 inductor	220uH +/-20%, .6A RMS .7A saturation	SRN6045-221M	back	17	row 64

Spotlight output connector 1

Reference	What it is	Value	Part number	Face	Sheet	Parts list
J9	Three-channel spotlight connector	SPOTLIGHT 3 PAIRS	BM06B-GHS-TBT(LF)(SN)	back	18	row 70

Test point 12

Reference	What it is	Value	Part number	Face	Sheet	Parts list
TP1	Test point on GND	GND		back	14	PCB feature
TP2	Test point on VIN24_RAW	VIN24_RAW		front	14	PCB feature
TP3	Test point on V24_BUS	V24_BUS		back	14	PCB feature
TP4	Test point on +5V	+5V		back	14	PCB feature
TP5	Test point on +3V3	+3V3		back	14	PCB feature
TP6	Test point on GATE_BIAS	GATE_BIAS		front	14	PCB feature
TP7	Test point on LIGHT_ENABLE_SAFE	LIGHT_ENABLE_SAFE		front	14	PCB feature
TP8	Test point on EFUSE_RESET_N	EFUSE_RESET_N		back	14	PCB feature
TP9	Test point on V24_SPOT	V24_SPOT		back	14	PCB feature
TP10	Test point on I2C_SDA	I2C_SDA		front	14	PCB feature
TP11	Test point on I2C_SCL	I2C_SCL		front	14	PCB feature
TP12	Test point on PCA_OE	PCA_OE		front	14	PCB feature

Assembly references

These are KiCad's own assembly drawings: component outlines, orientation and reference labels, at a glance. They are drawn in contrasting plotting colours, which are not the board's colours. Click either drawing to enlarge it, or open it in a new tab from the link beneath.

Front face. Open the front drawing in a new tab.

Back face, plotted mirrored — as you would see it looking at the back of the board. Open the back drawing in a new tab.

The complete schematic PDF contains the current 20-sheet hierarchy. The former four-page layout review is not offered as a current-revision document.

Downloads — the actual KiCad sources

View in browser opens a generated view of these exact source files. Download gives you the native project to open in KiCad. The browser views are faithful, but they are not a CAD editor.

Two things are worth knowing before you download a single file. The root schematic links to 19 child sheets and will not open completely without them. And single sheet files do not carry the custom symbol and footprint libraries this design uses — only the complete archive does. If you want to open the design, take the ZIP.

The .kicad_prl file, which holds personal editor state, is deliberately not published.

File	Format	Revision	Size	SHA-256 (first 12)	View in browser	Download	Notes
Complete KiCad project (everything below, plus libraries)	ZIP archive	cbb8d9fc	1.5 MB	b8af46039d91		download	Extract the whole archive together and open the project file. The root schematic depends on the 19 child sheets, and the custom symbol and footprint libraries only exist inside this archive.
KiCad project settings	KiCad project	cbb8d9fc	29 kB	8649760bbe1c		download	Opens the project in KiCad.
PCB layout (the board itself)	KiCad board	cbb8d9fc	6.1 MB	cbb8d9fc060c	open in the board viewer	download	The physical layout this page's board viewer is generated from.
Root schematic sheet	KiCad schematic	cbb8d9fc	18 kB	f4d0c51d47c9	open in the sheet browser	download	The root sheet on its own is not the whole design: it links to 19 child sheets, and without them it will not open completely.
Parts list (BOM)	CSV (UTF-8 with byte-order mark)	cbb8d9fc	33 kB	be0bb641b64e	read the table above	download	The exact part selection for this layout: 71 rows, 241 packages per board.
Complete schematic (20 pages)	PDF	cbb8d9fc	718 kB	22ce254aa3b6	open in the sheet browser	download	One page per sheet, in the same order as the sheet chooser above.
Assembly drawing, front	SVG drawing	cbb8d9fc	595 kB	ec19cb8def9e	see the drawings below	download	Component outlines and reference labels for the front face.
Assembly drawing, back	SVG drawing	cbb8d9fc	863 kB	503ee3785161	see the drawings below	download	Component outlines and reference labels for the back face. KiCad plots this one mirrored, as you would see it looking at the back of the board.
Fabrication reference (Gerbers, drills, IPC-D-356)	ZIP archive	cbb8d9fc	1001 kB	c8c4290f366a		download	Manufacturing outputs of the same source. Not a fabrication release, and not where a beginner edits the design.
Drill map, plated holes	SVG drawing	cbb8d9fc	165 kB	757858f50efc	see the advanced section	download	Every plated hole, by size.
Drill map, unplated holes	SVG drawing	cbb8d9fc	47 kB	893454921f12	see the advanced section	download	The unplated holes: the four M3 mounts and the two USB locating pegs.
Board outline drawing	SVG drawing	cbb8d9fc	1008 bytes	133d5a0de548	see the advanced section	download	The current cut line in a millimetre SVG frame; no dimension annotations.
Drill report	Text	cbb8d9fc	307 bytes	a7ef33047477		download	Hole counts for this export; six are unplated mounting/locator holes.
Schematic sheet 2: Controller	KiCad schematic	cbb8d9fc	111 kB	b797f7f753b9	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 3: Power Sequence	KiCad schematic	cbb8d9fc	28 kB	9959d9f02d9e	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 4: Can	KiCad schematic	cbb8d9fc	55 kB	b4647849bdc7	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 5: Usb	KiCad schematic	cbb8d9fc	87 kB	1bcb7af753db	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 6: Pwm	KiCad schematic	cbb8d9fc	55 kB	23eb28335661	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 7: Zone 1	KiCad schematic	cbb8d9fc	41 kB	779fac8d76a5	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 8: Zone 2	KiCad schematic	cbb8d9fc	41 kB	76a134a3ba34	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 9: Zone 3	KiCad schematic	cbb8d9fc	41 kB	0e5407daf5be	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 10: Zone 4	KiCad schematic	cbb8d9fc	41 kB	aa0d86d7eec8	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 11: Zone 5	KiCad schematic	cbb8d9fc	41 kB	dff4e2bb0726	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 12: Zone 6	KiCad schematic	cbb8d9fc	41 kB	5566a943be99	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 13: Zone 7	KiCad schematic	cbb8d9fc	44 kB	b2f5d4f31296	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 14: Test	KiCad schematic	cbb8d9fc	39 kB	66d5ab6e2c36	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 15: Power 1	KiCad schematic	cbb8d9fc	117 kB	68c45d514fe4	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 16: Power 2	KiCad schematic	cbb8d9fc	99 kB	29fc09860d14	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 17: Spot 1	KiCad schematic	cbb8d9fc	108 kB	3c6777d0558a	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 18: Spot 2	KiCad schematic	cbb8d9fc	37 kB	20593035a0a7	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 19: Monitor Expansion	KiCad schematic	cbb8d9fc	41 kB	4f4b5d0c2e76	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Schematic sheet 20: Central six-zone LED flex interface	KiCad schematic	cbb8d9fc	37 kB	3c11b0b947c8	open in the sheet browser	download	One child sheet. Single sheet files do not carry the project's symbol and footprint libraries -- only the complete archive does.
Component placement, both sides	CSV	cbb8d9fc	20 kB	51579ea014cd		download	Exact factory placement data; common top-view coordinates on both sides. No second mirror.
current-checks.json	JSON	cbb8d9fc / 0af25f8f	4 kB	99e7fc5bb72b		download	Revision-bound evidence: read each source hash and scope; historical results are not current simulations.
teaching-v0.1.json	JSON	Historical c046202e / earlier	374 kB	a358647e40b7		download	Revision-bound evidence: read each source hash and scope; historical results are not current simulations.

Provenance

Everything on this page is derived from one board file:

engineered-lighting-rev-a.kicad_pcb
SHA-256  cbb8d9fc060c7f2b3e6b27b096a5728e789e816102ddba393c69e91020144abb

The layer plots and schematic sheets were exported from that file with KiCad 10.0.3 and published here with their geometry untouched: only the XML wrapper, the invisible duplicate text and the baked editor colours were removed, so the page can theme them. Every published file's size and SHA-256 are recorded in the manifest, and the derivation is recorded in provenance.json.

Datasheet and sourcing links are reproduced from the current quote BOM, including inherited sourcing records. They were not re-checked when this page was built.

Earlier revisions of this design have their own hashes, and the simulations run against them stay bound to those hashes on this page. They are not relabelled as results for this board. Older wording in the project's own notes — describing bare boards for local hand assembly — is superseded by the September quote scope stated at the top.

Design corrections, and why they happened

Four changes are worth understanding, because each one came from finding that an assumption was wrong.

Capacitors lose value under DC bias. A ceramic capacitor's marked value is measured at almost no applied voltage; at its working voltage it can lose most of it. Two reservoirs were re-screened against characterised sample data and moved to 22 µF 25 V X7R parts in larger packages. The screen used sample data plus an engineering reserve — not guaranteed lifetime minima.

A protection part fed a rail it should not have. The original USB data protection had internal diodes tied to a local 5 V rail, so a host driving the data lines could push current into a supply that was supposed to be off. It was replaced with a ground-referenced part, and a data multiplexer now parks the controller's data lines until the supervisor qualifies its rail.

Ordinary logic cannot be trusted while its own supply collapses. Lighting enable now goes through a supervisor and a Schmitt-input gate rather than plain logic, and the pull-down that holds the enable low was strengthened.

Clamping at the input is not clamping at the load. The input suppressor clamps at 53 V, which is far above what the spotlight drivers tolerate, so flat-clamp devices were added locally on the bus and on the spotlight rail. They are pulse devices with a 12 mA DC limit — none of them is a brake.

On power: the supply is a provisional 24 V / 5 A / 120 W unit, and the initial commissioning envelope is 4 A for the whole board. The load model gives about 73 W under constrained colour mixing; running all three colours at full duty simultaneously is outside that model at about 126.6 W. Actual strip and motor currents are unmeasured. Commissioning also stays at or below 0.50 A RMS per radial zone, conditional on local fuse air at or below 85 °C and verified strip currents/PWM limits. The 0.75 A fuse is not a current clamp; the 0.60 A positive / 0.20 A channel stress cases are not continuous operating ratings.

What has been checked — and what has not

The current digital checks below bind to the exact downloadable board hashes. They were completed for the electrical baseline; the current snapshot verifies all packaged hashes and records the separate silkscreen-only preservation evidence. The new viewer export adds identity, geometry and schematic-sheet checks. No hardware simulation was rerun merely to update this page, and no result is a physical measurement.

Check	Result on this revision	What ran it
Current branding delta	Zero current DRC/unconnected items; all non-back-silkscreen native objects identical to electrical baseline 80195efd	cbb8d9fc branding verification
Board / schematic / BOM parity	262 features; 241 fitted components; 71 BOM rows; 786 logical pins, 757 assigned and 29 no-connects; 879 physical pad objects	80195efd baseline parity plus current read-only exporter identity checks
Electrical rules and physical connectivity	Baseline ERC and physical-pad connectivity passed, including rejected seeded missing copper; preserved exactly by the branding delta	80195efd FINAL-NATIVE-CHECKS; not a new analogue simulation
Manufacturing export comparison	Current 14 non-back-silkscreen films and both drill files match baseline; baseline independent CAM compared 12 films and 868 drills	Fresh cbb8d9fc exports and 80195efd CAM checks
Arm connector change	J9 combines three independent LED pairs; J10/J11 removed. J13 tilt and J12 pan remain separate. No returns are joined	Current native schematic, six J9 contacts and matched placement data
Central LED interface preserved	J2 and the upper tail are unchanged from the reviewed 30-contact interface	Native preservation; physical mating is unmeasured

And here is the honest other half. None of this has been done:

• No board has been powered. There is no measurement of any kind on this revision.
• No firmware has been built or flashed. The channel map is an integration contract, not code.
• The factory stack-up, finished thickness, copper weight and plating are not accepted yet.
• The 90 Ohm USB differential geometry is a request to the factory. Historical modelled cases on earlier native geometry are not a current-board impedance guarantee.
• No USB certification, enumeration test or electrostatic-discharge test.
• The coupled startup of the two switching converters was never qualified; the vendor model would not run.
• Real falling-edge timing, reset recovery and inhibit behaviour are hardware observations not yet made.
• No EMC, radio or in-enclosure antenna measurement.
• Motor regeneration has no qualified path. Nothing on this board is a brake.
• No enclosed-temperature measurement or full-board thermal simulation on this revision. Historical copper-solver totals are not current results.
• Actual strip and motor currents are unmeasured; the load model is conditional arithmetic.
• C504 final factory installation and the no-wash J2 assembly sequence need supplier approval.

Advanced — the layer stack and fabrication outputs

The stack, the drill maps and the raw manufacturing files

Fabrication targets, all of them quotation targets rather than accepted facts: 1.6 mm FR-4, eight copper layers, 1 oz finished copper per layer, black solder mask and white silkscreen on both faces, ENIG finish. The factory-approved stack and the 90 Ω USB geometry are still open.

The intended layer purposes are: front copper for components, signals and local power; In1 a ground reference; In2 24 V distribution and reviewed signal routes; In3 a ground reference with an inherited PCA_OE route/slot; In4 signals; In5 signals and protected branches; In6 ground; back copper for components, signals and local power. Those are explanatory summaries. Look at the real copper in the viewer: the voids are real, and a layer's purpose is not proof that every shape on it belongs to one net.

Gerbers, drill files and an IPC-D-356 netlist describe the bare board. They are manufacturing outputs, not the place to read or edit a circuit, and browsers do not render them natively — which is why the drill maps and the outline drawing are published as SVG companions alongside the raw archive. All of them are in the downloads table.

When the boards arrive

This checklist is your own bench record

Ticking these boxes saves state in your browser only. Nothing is sent anywhere, and a ticked box on this page is not a project result. The items below are adapted from the project's first-hardware checklist, which is a plan: none of it has been carried out.

Inspect before you power anything. Confirm the fitted fuse values against the parts list, then check pin 1 orientation on every IC, the polarity of C504 and the diodes, and that the connectors are the ones you expect on the face you expect. Ask the assembler for their inspection results on the U10 and U14 thermal joints and on J14's four shield stakes. Stop for a solder bridge, a wrong part, a wrong polarity or an unexplained low resistance — correct it and inspect again before applying power.

Then, in this order, with a current-limited supply and ARM open:

• Rails only: no loads, no USB, ARM open. Log TP2–TP5 and the input current through startup. Set the supply's limit from the actual startup budget — the bulk capacitor alone draws roughly 0.5 A while it charges, so too low a limit prevents normal startup and is not a board fault. Stop on a rail outside its window, on persistent current limiting, or on repeated latch cycles.
• Outputs disabled: measure TP6, TP7 and TP12 and all 21 gates with ARM open. TP7 must be at most 0.35 V, with 0.30 V as the target. Stop if any gate stays biased on.
• Reset and recovery: record 3.3 V, READY, MCU_EN and TP7 through startup, a controlled supply decay, repeated power cycling and a manual reset. Confirm that a fresh arming is required afterwards.
• USB, with 24 V present: check enumeration in both connector orientations, and check that the presence signal and the data parking behave in all four host / 24 V combinations.
• Unloaded control: verify both expander addresses, the explicit mode initialisation, and every channel's off, on and duty encoding — including the open-drain complement and the two remapped channels. Stop on a swapped channel or an inverted polarity.
• One optical load at a time, starting with a dummy load. Compare spotlight current against the calculated 0.317–0.350 A band and record ripple, overshoot and inductor temperature.
• Combined load, increased deliberately, staying inside the 4 A envelope while watching rail minima and temperatures.
• CAN and motors last, after a separate motion review: check termination and harness polarity unpowered — about 60 Ω across a finished bus — before anything moves.

Risk register

Risk	Why it matters	What would settle it
No board has been powered	Every electrical number on this page is a calculation or a datasheet limit	The bring-up sequence above, on a real board
Factory stack and USB impedance not accepted	The 90 Ω differential target is a request; earlier modelled cases are historical, not a current impedance guarantee	The manufacturer's stack proposal and a coupon
Assembly process not approved	Thermal-via treatment, the bulk capacitor's installation and the 0.4 mm-pitch part all need a process answer	PCBWay's acknowledgement of the assembly clarifications
Motor regeneration has no path	Nothing on this board is a brake, and the clamps are pulse devices	A designed brake and a measured regeneration test
Coupled converter startup unqualified	The vendor model would not run; only isolated cases passed	Scope captures of both rails through startup
Firmware does not exist	The channel map, the open-drain complement and the two remaps are a contract, not code	A diagnostic build, verified channel by channel

Related reading

• Doc 10 · The Flex Circuits — the proposed manufactured wiring that plugs into this board's connectors.
• Doc 8 · Build the Fixture — the hand-soldered stage this board replaces.
• Doc 4 · Build the Full Fixture Bench — where the architecture was proven.
• Doc 6 · The Message Contract — the interface every part of the system obeys.