Smart Espresso Scale
Worked for 23 mins 27 sec
Created a project doc
Layout Verification Notes — Smart Espresso Scale
Board set to compact 50 x 80 mm rounded rectangle. Stackup set to Standard 4 Layer.
Completed the PCB layout pass: the board is 50 × 80 mm, 4-layer, placed with the ESP32 antenna intentionally overhanging the top edge, and fully routed with no airwires/overlap/dangling/invalid-layer errors remaining.
Open items:
- U1 still reports a body-over-edge warning; this is intentional for the ESP32 antenna keepout.
- BOM still needs final MPNs for generic resistors/capacitors, L3 inductor, and J4 header; TP1–TP4 were excluded from BOM/PnP.
- Routing used 0.1 mm traces to enter fine-pitch parts, so power paths should be widened/poured before manufacturing.
I documented the verification details in Layout Verification Notes.
Suggested next steps:
- Select final passive/inductor/header MPNs.
- Widen/pour VBUS, BAT, SYS, REG_IN, and 3V3 power paths.
- Verify antenna keepout visually/mechanically.
- Export Gerbers/BOM/PnP once BOM MPNs are finalized.
Finalize BOM and power
Select final MPNs
Widen power paths
Verify RF keepout
Run manufacture export
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Technical Construction File Notes — Smart Espresso Scale
Status
Draft design-stage notes; not a certification package.
Applicable Areas
- FCC Part 15 / CE RED likely applicable due to ESP32-C3 WiFi/BLE module.
- Battery charging safety review applicable due to USB-C LiPo charging.
Wireless Technology Summary
Table
| Module | MPN | Technology | Antenna | Notes |
|---|---|---|---|---|
| U1 | ESP32-C3-WROOM-02-N4 | WiFi 2.4GHz + BLE | Integrated PCB antenna | Use module datasheet antenna keepout; confirm regional modular approvals before production. |
Required Documentation Checklist
- Draft block diagram: in Project Specification.
- Draft BOM source: current schematic.
- Draft firmware outline: Firmware Starter.
- Final schematic PDF after review.
- Final PCB layout/Gerbers after layout.
- ESP32-C3 module FCC/CE grant/certification evidence.
- Accredited EMC/RF test reports.
- Final user manual and labeling.
RF Design Notes
- Place ESP32 module antenna at board edge.
- Keep copper, traces, vias, and components out of the antenna keepout on all layers.
- Do not place the load-cell analog front end or switching regulator near the antenna region.
Safety / Battery Notes
- Use a protected 1S LiPo pack unless a future revision adds on-board cell protection.
- BQ24074 TS is currently fixed by a 10k resistor; this does not measure battery temperature.
- Charge current is set to approximately 250mA. Confirm it is <= battery manufacturer recommended charge rate.
Open Items
- Confirm exact ESP32-C3-WROOM-02-N4 certification IDs for target markets.
- Confirm enclosure ingress/splash strategy for espresso-counter use.
- Review product labeling and user safety warnings before manufacturing.
Status
Applicable Areas
Wireless Technology Summary
Required Documentation Checklist
RF Design Notes
Safety / Battery Notes
Open Items
