I’ll build the complete schematic around an ESP32 WiFi module, USB‑C 5V input, protected 3.3V regulation, external ultrasonic sensor connector, programming/reset circuitry, and status LEDs. I’ll first select datasheet-backed parts, then add/wire the schematic, document the power budget, and run design checks.

I selected the main parts: ESP32-S3-WROOM-1, AP2112K 3.3V LDO, USB-C receptacle, USB ESD array, resettable fuse, headers, switches, and indicator LEDs. I’m adding the schematic components now, with the sensor interface kept generic until a specific ultrasonic sensor module is chosen.

Schematic is complete for the ESP32-S3 WiFi ultrasonic water flow meter: USB-C 5V input, fuse + ESD protection, AP2112K 3.3V regulator with required caps, ESP32 reset/boot network, native USB, UART header, sensor connector, and three status LEDs.

Validation: ERC is clean; remaining review errors are PCB-layout-only airwires/overlaps because placement/routing has not started yet. I also created Project Specification, Design Notes, and Firmware Starter.

One design caveat: the exact external ultrasonic sensor model is still unspecified, so the connector supports a generic pulse/UART-style sensor interface and should be updated if the chosen sensor requires 5V, 12V, RS485, or an analog ultrasonic front end. Ready to move to PCB layout when you are.