I renamed the project to USB-C WiFi BLE Environmental Node and updated the description. I also created a project specification file capturing the requirements, architecture, assumptions, and initial power budget: Project Specification.
I selected and researched likely core parts:
- MCU/radio: ESP32-C3-WROOM-02-N4 — Wi‑Fi 2.4 GHz 802.11 b/g/n + BLE 5, integrated PCB antenna, native USB pins.
- Sensor: SHT40-AD1B-R2 — low-power I2C temperature/RH sensor.
- USB-C connector: USB4105-GF-A / USB-C 2.0 receptacle.
- Input protection candidate: MP5036AGJ-P eFuse/load switch, but its datasheet text was not accessible in this run, so wiring was not started.
- Regulator: AP2114H-3.3TRG1 3.3 V / 1 A LDO; datasheet confirmed 4.7 µF input/output capacitors, EN behavior, 1 A rating, and thermal limits.
- USB data ESD: USBLC6-2SC6.
- VBUS ESD: TPD1E05U06DPYR.
- Reset/boot buttons and status LED candidates were found.
Initial power sizing:
- ESP32-C3 rail should be designed for at least 500 mA peak.
- SHT40 is sub-mA during measurement, unless heater is used.
- 3.3 V rail target is about 510 mA peak minimum, so the 1 A AP2114 LDO has current margin, but layout copper/thermal handling will matter.
No schematic components were added or wired yet because execution credits ran out before the build step. Remaining work is to add components, wire the USB-C protection/regulator/ESP32/SHT40/support passives, create firmware notes, run schematic review, and fix any violations.