USB-C Temperature Humidity Sensor Node Design


I found suitable core parts: ESP32‑C3 module for Wi‑Fi/BLE 5, Sensirion SHT40 T/RH sensor, USB‑C receptacle, TPS25947 eFuse for OVP/UVLO/OCP/reverse blocking, HUSB238A for Type‑C source-current/PD awareness, and AP2112K 3.3 V LDO.
I’m blocked because the project has no available ACUs, so I can’t continue executing design actions or run validation.
Completed so far:
  • Renamed the project to USB-C WiFi BLE Sensor Node and updated its description/properties.
  • Selected and added the main schematic parts:
    • ESP32-C3-MINI-1-N4 Wi‑Fi/BLE module
    • Sensirion SHT40 T/RH sensor
    • USB-C receptacle
    • TPS259474 eFuse for OVP/UVLO/OCP/reverse-current blocking
    • AP2112K-3.3 600 mA LDO
    • HUSB238A USB-C/PD sink/current-detection controller
    • USB ESD protection, reset/boot switches, status LED, and support passives
  • Consulted datasheets for ESP32-C3, SHT40, and AP2112K:
    • ESP32-C3 needs 3.0–3.6 V, ≥0.5 A supply capability, EN not floating, GPIO9 boot pull-up, GPIO18/19 as USB D−/D+.
    • SHT40 runs from 1.08–3.6 V, I2C address 0x44, needs I2C pull-ups and local decoupling.
    • AP2112K uses 1 µF min input/output capacitors, EN high for normal operation.
Remaining work:
  • Finish datasheet checks for TPS259474, HUSB238A, USB-C connector, and USBLC6 ESD part.
  • Correct individual passive values/properties where needed.
  • Wire the full schematic: USB-C, CC/PD controller, eFuse, 3.3 V rail, ESP32, SHT40, I2C, USB data, reset/boot, LED.
  • Run schematic review/ERC and fix violations.
  • Create the required project files: project specification, power budget, firmware starter, FCC/CE regulatory notes, and board bring-up plan.
Check power ICs
Wire schematic
Run review
Power budget doc
Compliance docs

U2
J1
U3
U4
U1
Not Recommended for New Designs
Manufacturer Part Number
ESP32-C3-MINI-1-N4
D1
C7
Capacitance
100nF
LED1
C3
Capacitance
100nF
C4
Capacitance
100nF
C8
Capacitance
100nF
C6
Capacitance
100nF
C1
Capacitance
100nF
U5
C2
Capacitance
100nF
C5
Capacitance
100nF
R5
Resistance
10kΩ
R7
Resistance
10kΩ
R2
Resistance
5.1kΩ
SW1
R4
Resistance
10kΩ
R6
Resistance
10kΩ
R8
Resistance
1kΩ
SW2
R3
Resistance
10kΩ
R1
Resistance
5.1kΩ

USB-C WiFi BLE Sensor Node

USB-C WiFi BLE Sensor Node thumbnail