abse/museair-usb

docs/PROTOTYPE-FABRICATION-REVIEW.md

# Prototype fabrication review

The bare PCB is ready for prototype fabrication based on the checked native board, Gerber short scan and native DRC: zero violations and unconnected items. Circuit/routing and critical pin mapping checks pass. BOM/CPL match the native board; all65 PCBA placements are on top. Exact imported footprints and the mechanical hole pattern are retained.

All71 component/test-point explanations are present. The website style analyzer reports zero issues. C3 and C12 are grouped inside the POWER drawing area, removing a separate sheet-boundary warning; electrical nets and PCB geometry/copper are unchanged.

Confirm JLCPCB procurement before an assembled-board order: J6 C160403 currently shows25 overseas units but zero pre-sale quantity. J7 C177225 shows available pre-purchase stock. None is reserved. Use the checked BOM and CPL, and confirm orientation in the assembler preview.

L1 SWPA4030S4R7MT catalog ratings are2A continuous,3.2A saturation and78mΩ DCR, sufficient for the intended600mA ESP rail. These are current JLCPCB catalog specifications; the manufacturer PDF could not be retrieved. Do not treat the complete converter as a characterized2A supply.

Bring up prototypes on a stable5V USB-C supply with sufficient current. Check both3.3V rails first, program through J6 at3.3V logic, then test boot/reset/ASK, sensor/display I2C, microphone and low-volume speaker playback. Measure current, ripple and temperature, and validate enclosure airflow, seals, connector fit and RF. Firmware and physical hardware tests are outstanding; CAD/DRC checks do not establish those results.

The checked native KiCad board is the fabrication authority. Use order/gerbers.zip, order/bom-jlcpcb.csv and order/cpl-jlcpcb.csv. Detailed evidence: validation/prototype-fabrication-roundup.json and validation/production-audit.json.