imrishabh18/fitness_watch

VALIDATION.md

# Centered heart-rate sensor — version 1.0.12

U5 (MAX30102) has moved from (13, -10) mm to (0, 0) mm, at the centre of the 50 × 40 mm board on the wrist-facing bottom layer. Its power/decoupling cluster moved with it: U6 (-6, 0), R17 (5, 0), C15 (-3, -4.4), C13 (4, 3.5), C16 (4, -3), C12 (4, 6.5), C14 (-7, -3.5), all in millimetres on the bottom.

The battery-only power path, J2 UART programming, top-side motor location and optical/motion sensor connections are preserved. Copper was rerouted and repaired; reviewed-routes.json and routing-anchors.json preserve the verified result with endpoint and net guards. The motion-sensor centre keepout and antenna keepout remain enforced.

Validation with global tscircuit 0.0.2506:

- PCB DRC: zero errors.
- Default tsci check: zero errors, 33 existing schematic/component annotation warnings.
- Netlist: zero errors and warnings.
- Gerber short detection: no shorts.
- TypeScript: passed.
- 69 connectivity assertions passed; additional assertions verify U5 is on the bottom and at the centre.
- PCB placement DRC: zero errors/warnings. R14/C11 orientation heuristics remain advisory after successful routing.
- Schematic R6/U2 label collision corrected. Presentation suggestions (box dimensions, symbol orientation, grouping) remain; no schematic component/net-label collisions remain.

The enclosure still needs a smooth back and a sealed optical window aligned to U5. This relocation is not a completed enclosure design or a guarantee of heart-rate accuracy. All other bottom parts and solder joints must remain inside the enclosure. Firmware, battery/power and mechanical validation remain outstanding.

The BOM remains 36 placements/22 exact supplier codes. Stock data is the September 10 snapshot and was not refreshed for this placement-only revision.