Marker lamp controller rev b

Fabrication Design

This directory contains Revision A and Revision B of the two-layer marker-lamp controller. Revision B is the current fabrication design.

Files

• marker-lamp-controller.kicad_pcb — generated KiCad 10 PCB.
• marker-lamp-controller-rev-b.kicad_pcb — corrected Revision B PCB.
• generate_pcb.py — deterministic PCB generator using KiCad's pcbnew Python module.
• circuit-netlist.md — readable authoritative circuit connectivity.
• revision-b-notes.md — corrections found while assembling Revision A that must be incorporated before the next board order.
• BOM.csv — orderable manufacturer and DigiKey part numbers.
• drc-report.txt — KiCad board DRC result.
• fabrication/ — OSH Park Gerbers and separate plated/non-plated drills.
• fabrication-rev-b/ — Revision B OSH Park Gerbers, drills, and upload ZIP.
• board-render.png — top-side board preview (custom hand-solder footprints do not carry 3D body models).
• board-render-rev-b.png — Revision B top-side board preview.

Revision B includes top-side reference designators, diode cathode markings, C3 polarity, U1/U2 pin-1 cues, Q1 lead labels, the complete J1 pinout, and the project source URL to support hand assembly and design-source identification.

The PCB generator and circuit-netlist.md are authoritative for Revision B.

Connector

Board header:

• Same Sky TBP01R1-508-04BE

Mating pluggable terminal connector:

• Same Sky TBP01P1-508-04BE

Pinout:

1. SENSE — driver-side rear parking output, C4483 cavity 10, violet/green.
2. BATT+ — separately fused 12 V feed; use a 2 A fuse.
3. LAMP+ — switched positive output to the 0.25 A grille LEDs.
4. GND — chassis ground and grille LED return.

Board construction

• 80 × 45 mm
• Two copper layers
• 1 oz copper
• Minimum designed trace/space: 0.20 mm / 0.20 mm
• Signal traces: 0.35–0.60 mm
• Power/load traces: 1.2 mm
• Vias: 0.8 mm finished pad, 0.4 mm drill
• Four 3.2 mm non-plated mounting holes
• Mounting-hole centers: 72 × 37 mm
• Components on the top side

These values exceed the OSH Park two-layer minima of 0.1524 mm trace/spacing, 0.127 mm annular ring, and 0.254 mm minimum drill.

DigiKey availability review

The BOM was checked against DigiKey stock on 2026-07-24. Stock changes continuously, so verify it again before ordering.

• BSP762TXUMA1: stocked, cut tape available.
• VO617A-4X017T: stocked, cut tape available.
• TBP01R1-508-04BE header: stocked.
• TBP01P1-508-04BE mating plug: stocked.
• STPS2H100A and SMBJ22A: stocked, cut tape available.
• SBC807-40LT1G: stocked, automotive-qualified.
• 1N4148WS: stocked alternate selected.
• BZT52-C5V1-QX: stocked, automotive-qualified.
• CGA6P1X7R1E106K250AC: stocked, automotive-qualified.
• C0805C104K5RAC7210: stocked, active replacement for an obsolete Murata bypass capacitor considered during selection.
• EEE-FK1H470P and all three Yageo resistor values: stocked.

Regenerate

python3 generate_pcb.py

Run from this directory or from the project root using the full relative path.

Generate the top-side repository preview from the project root with:

kicad-cli pcb render --side top --quality basic --background opaque \
  --width 1600 --height 900 --zoom 1.15 \
  -o hardware/kicad/board-render-rev-b.png \
  hardware/kicad/marker-lamp-controller-rev-b.kicad_pcb

The custom hand-solder footprints do not include 3D component-body models, so the render intentionally shows the bare board, pads, and assembly silkscreen.

Status

An assembled Revision B board has been bench tested, installed, and verified working in the vehicle with the intended 0.25 A marker-lamp load. It remains an engineering prototype; independent builders should bench test every assembly and characterize turn-on/off behavior, reverse polarity, output short protection, thermal behavior, and vehicle sleep current before permanent installation.

KiCad 10 DRC reports zero violations, zero unconnected pads, and zero footprint errors for Revision B. This verifies the artwork rules and connectivity, not vehicle behavior.