Complete: I created and wired the full schematic for the USB-C powered ESP32-S3 WiFi water flow meter, including 3.3 V buck regulation, 12 V boost sensor power, MAX3485 RS485 interface, USB-C protection/CC resistors, reset/boot circuitry, UART header, and status LEDs. Review returned no ERROR/WARNING/OPEN ERC issues.

I also created Design Notes with the architecture, power budget, assumptions, and pin map, plus Firmware Starter with PlatformIO/Arduino Modbus RS485 starter code. The main remaining assumption is the exact ultrasonic sensor’s Modbus register map; update the firmware once the sensor datasheet is chosen.

Schematic is ready for layout. Want me to proceed with board sizing and component placement?

I’ll size the PCB first, set an appropriate stackup, then place components by functional block with the ESP32 antenna at an edge, USB and sensor connectors on board edges, and decoupling/power passives near their ICs. After placement I’ll run a DRC review and adjust if needed.

Done. I resized the PCB to 100 × 80 mm with rounded corners and a 4-layer stackup, then placed all components by functional block.

Placement is clean: ESP32 is at the top edge with antenna overhang, USB-C is on the left edge, the sensor terminal is on the right edge, power stages are grouped, and user-facing LEDs/buttons/header are accessible. The only review errors now are expected unrouted connections because routing has not been performed yet.

Ready for routing when you are.