• Project description updated and mermaid system‐architecture flowchart added. • ESP32 module (U1) and DevKitC footprint (U3) placed. • External buck regulator (U2) integrated. • Decoupling and bulk capacitors added: C1, C2, C3. • Resistors for LEDs (220 Ω), echo divider (2.2 kΩ/1 kΩ), I²C pull-ups (4.7 kΩ ×2) added. • Programming/test pads (TP1–TP6), 6-pin sensor header (J1), USB-C (J2), 2-pin power header (J3) placed and nets connected. • Package footprints assigned for all resistors (R1–R6) and capacitors (C1–C3), plus modules (U1–U3). • PCB outline set to 70 mm×40 mm, 2-layer stackup with bottom GND plane configured. • Four corner mounting holes added. • Component availability and lifecycle statuses enriched. • Gerber and Pick-and-Place files exported.

• Messaging the user with the raw mermaid code for the system architecture. • Assigning footprints to connectors (J1–J3) and test points (TP1–TP6). • Net classification and trace-width rule setup. • Component placement on PCB. • Auto-routing of nets. • ERC/DRC reviews and fixes. • BOM CSV generation.

Next step Run electrical‐rule and design‐rule checks (ERC/DRC) in the schematic and PCB to catch and correct any connectivity or manufacturing errors before placement and routing.