Auto-Layout Placement Review

flux

You’re right — that PDF export appears unusable for schematic review.
I generated alternate documentation instead:
Gerbers do not include schematic sheets; the netlist/connectivity files are the right companion documents for fabrication and debugging.
jacobwtyler

jacobwtyler

export .kicad_pcb and .kicad_sch files

flux

I’ll check whether a native KiCad project export is available for this design and provide the closest usable export if not.

flux

I can’t generate native .kicad_pcb or .kicad_sch files from this project right now — Flux does not currently expose a KiCad project-file export for this design.
Closest usable files already generated are:
  • Gerbers for fabrication
  • Pick-and-place CSV for assembly
  • BOM CSV
  • IPC-D-356 netlist
  • SVG/PDF-style documentation fallback
I also flagged the missing KiCad export capability internally.
Export manufacturing files
Export netlist
KiCad recreation steps
Export documentation
Create BOM spreadsheet
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Files

Schematic

Layout

Preview

Project Specification
Project Overview
  • Project Name: ArcBridge
  • Product: ArcBridge by Bridgeway Audio
  • Purpose: Digital-to-digital audio converter that accepts S/PDIF from TOSLINK or coaxial RCA and embeds the selected audio into HDMI with dummy 640x480 black video, ARC return audio on HDMI pin 14, and CEC participation.
  • Primary Use Case: Replace a commercial HDMI audio embedder + HDMI dongle in an RV AV chain feeding a FeinTech VAX04101A HDMI matrix for eARC distribution.
  • Firmware Repo: https://github.com/jacobwtyler/pico-ddc (subdirectory: pcb-v2)
Architecture Summary
  • MCU/Core: Raspberry Pi Pico 2 castellated module used as the main controller and TMDS generator.
  • Audio Inputs:
    • TOSLINK optical receiver
    • Coaxial RCA S/PDIF input with AC coupling and mid-supply bias
  • HDMI Output: Type-A receptacle with four AC-coupled TMDS differential pairs, HPD pull-up, VBUS sourcing, CEC direct connection, and AC-coupled ARC S/PDIF.
  • User I/O: Two status LEDs, SPDT input-select switch, optional 2-pin RF/button header.
  • Power: Entire board powered from the Pico 2 USB-C connector; no separate onboard supply.
Functional Blocks
  1. Pico 2 Core / TMDS Source
  2. HDMI Output Interface
  3. TOSLINK Receiver Input
  4. Coaxial S/PDIF Input Bias Network
  5. User Controls and Indicators
  6. Mounting / Mechanical Features
Key Schematic Requirements
  • Route Pico GP12-GP19 as HSTX TMDS source pairs through AC coupling capacitors to HDMI pins 1/3/4/6/7/9/10/12.
  • Drive HDMI pin 14 from Pico GP11 through a 100 nF AC-coupling capacitor for ARC S/PDIF.
  • Hold HDMI HPD high from VBUS with a 10 kOhm pull-up.
  • Connect HDMI pin 18 directly to VBUS from the Pico module.
  • Leave HDMI DDC pins 15/16 unconnected.
  • TOSLINK receiver operates from 3.3 V with a local 100 nF decoupling capacitor.
  • Coax input uses 100 nF AC coupling into a 2 kOhm / 2 kOhm divider to 3.3 V and GND, centered at 1.65 V into Pico GP1.
  • Switch common goes to GND; throws go to Pico GP4 and GP5.
  • LEDs are active-high from Pico GPIOs through 330 Ohm resistors into LED anodes with cathodes to GND.
  • Add 10 uF bulk decoupling on 3.3 V near Pico and 1 uF bulk decoupling on VBUS near HDMI.
PCB / Manufacturing Requirements
  • Board: JLCPCB 4-layer, 1.6 mm, ENIG.
  • Stackup Goal: Top signal / inner GND plane / inner 3.3 V plane / bottom signal.
  • High-Speed Constraint: TMDS pairs on top layer only with ~100 Ohm differential geometry per user requirement.
  • Assembly Split: JLCPCB assembles SMD parts; user hand-solders Pico module and through-hole parts.
  • Mechanical: Four M3 mounting holes, 1.5 mm corner radius, top-edge access for USB-C/TOSLINK/RCA/switch, bottom-edge HDMI connector.
Validation Goals
  • Schematic must match device datasheets and user pin map.
  • Every power pin must have proper supply and decoupling.
  • ERC should be clean or any residual warnings must be explicitly justified.
  • Pause for user confirmation before moving from schematic into layout.

  • Project Overview

  • Architecture Summary

  • Functional Blocks

  • Key Schematic Requirements

  • PCB / Manufacturing Requirements

  • Validation Goals