Smartwatch PCB Design Guide
Thought for 5 mins 26 sec
Placed 50 component(s): TP2, TP6, R3, R10, SW1, C11, R12, R6, U1, U6, TP10, C15, TP5, U3, C13, C16, R9, U2, R2, C3, TP4, TP3, C14, C2, SW3, TP9, J2, U7, R5, C4, C10, C1, TP8, R1, R7, J1, C12, DS1, C7, R8, R4, TP7, C5, TP1, R11, SW2, C9, D1, C8, C6
Thought
Work done
- Resized the PCB to 100 × 75 mm, 4-layer, to add routing margin while staying within a common prototype size.
- Re-placed the layout so DS1 remains top-side, while U4/MAX30102 and U5/MLX90614 are on the bottom wrist side, close together near the center beneath the OLED.
- Kept the ESP32-C3 antenna at the edge facing outward, with USB-C, battery connector, switch, and power parts arranged away from the sensor cluster.
- ✅ Skin-touch sensors are now bottom-side and centered under the OLED.
- ✅ OLED remains top-side and antenna placement was preserved at the board edge.
- ❌ Routing is not complete: the latest validation still reported 87 airwires and 12 overlapping-copper issues before the final re-placement, and I could not continue to reroute/validate further.
- ❌ Manufacturing export files were not generated, because export should only happen after DRC is clean.
- Run routing cleanup/autorouting next, then re-check DRC until airwires and copper conflicts are cleared.
- After DRC is clean, generate the Gerber, BOM, and pick-and-place manufacturing package.
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Layout Update Status
Current mechanical orientation
- Board resized to 85 mm x 60 mm, rounded rectangle, to fit the integrated top OLED and bottom wrist-contact sensors with better routing clearance.
- DS1 AOM12864A0-1.3BW-ANO OLED is an integrated top-side display and must face upward through the top glass/window.
- U4 MAX30102 and U5 MLX90614 are bottom-side wrist-contact sensors. They must be kept level with one another and aligned to enclosure cutouts/windows.
- U1 ESP32-C3-WROOM-02-N4 remains top-side with antenna facing the outward board edge and a required no-copper/no-trace antenna keepout.
Stackup / ACU decision
- The original goal was JLCPCB 2-layer <=19 ACU.
- The current design remains on 4 layers because the integrated OLED, USB-C/ESD, ESP32 module, charger/regulator, bottom-side optical/IR sensors, and many test/support parts create high routing density and strict keepout conflicts.
- A 2-layer board should only be attempted if the design is simplified or a human accepts a higher risk of routing/return-path/keepout compromises.
Export gate
- Manufacturing files must not be generated until airwires and copper-overlap checks are clean.
Current mechanical orientation
Stackup / ACU decision
Export gate
