USB-C WiFi BLE Sensor Design
Worked for 3 mins 22 sec
I started the USB-C Wi‑Fi/BLE temperature/humidity sensor node design and completed the early schematic setup work before execution stopped.
Completed:
- Renamed the project to USB-C WiFi BLE Environmental Sensor and updated the description.
- Created initial project files:
- Selected and added the main schematic parts:
- U1: ESP32-C3-MINI-1-N4 Wi‑Fi 802.11 b/g/n + BLE 5 module
- U2: SHT40-AD1F-R2 digital temperature/humidity sensor
- U3: TPS259474LRPWR eFuse for OVP/UVLO/OCP/reverse-current protection
- U4: AP63203WU-7 3.3 V / 2 A buck regulator
- J1: USB-C receptacle
- D1: TPD2EUSB30A USB D+/D− ESD protection
- Consulted datasheets for the ESP32-C3 module, SHT40 sensor, TPS25947 eFuse, AP63203 buck regulator, and USB ESD protector.
Key design decisions already grounded in datasheets:
- ESP32-C3 requires 3.0–3.6 V, with a supply sized for at least 0.5 A.
- ESP32-C3 USB native pins are IO18 = USB_D− and IO19 = USB_D+.
- ESP32-C3 EN must not float; datasheet recommends an RC delay, typically 10 kΩ + 1 µF.
- SHT40 runs from 1.08–3.6 V, uses I2C address 0x44, and needs 100 nF decoupling.
- AP63203 fixed 3.3 V buck recommended external parts:
- 10 µF input capacitor
- 3.9 µH inductor
- 2 × 22 µF output capacitors
- 100 nF bootstrap capacitor
- TPS259474 eFuse:
- IN range 2.7–23 V
- Adjustable UVLO/OVLO
- ILM resistor required; do not leave ILM floating
- ITIMER may be left open for fastest overcurrent response or populated with a capacitor for blanking
- PG is open-drain and needs pull-up if used
Remaining work:
- Add all support passives: USB-C CC pull-downs, buck inductor/caps, eFuse threshold/current-limit parts, ESP32 EN/reset/boot parts, I2C pull-ups, decoupling, LED, and test points.
- Wire the full schematic.
- Run ERC/review and fix all violations.
- Create firmware starter and board bring-up plan files.
- After schematic is clean, ask for approval before moving to PCB layout.
Finish schematic
Size eFuse resistors
Complete USB-C
Run ERC/DRC
Document decisions
