USB-C Sensor Node

flux

Implemented the schematic for the USB-C powered Wi‑Fi/BLE temperature/humidity node. It uses a SiWG917 Wi‑Fi/BLE 5.4 module, SHT41 T/RH sensor, USB-C sink input, TPS25940 true reverse-blocking eFuse with OVP/UVLO/OCP/soft-start, MP28301 3.3 V buck regulator, ESD protection, reset/ISP/SWD debug, I2C pull-ups, and status LED.
Created project files:
Open items:
  • PCB layout/routing is not done yet, so airwire DRC errors are expected.
  • Generic passives still need final manufacturer MPNs before manufacturing export.
  • Layout must enforce the SiWG917 antenna keepout and thermal isolation around the SHT41.
Suggested next steps:
  1. Set board size/stackup and move into PCB placement.
  2. Place U1 at the board edge with antenna keepout and U4 away from heat sources.
  3. Route power, buck, I2C, SWD/UART, and USB-C protection paths.
  4. Assign final passive MPNs and run full DRC/manufacturing checks.
mubashir

mubashir

Set up the board size and stackup, then place the components for RF and thermal best practices.

flux

The schematic is complete with 46 components, including the SiWG917 radio module, SHT41 sensor, protected USB-C input, TPS25940 eFuse, and MP28301 buck regulator.
I can’t configure the PCB or place components because the account currently has no available ACUs, so AI execution is unavailable. Remaining work:
  • Choose and set the board dimensions and layer stackup.
  • Place the SiWG917 at a board edge with its antenna facing outward and the full antenna region free of copper, traces, wiring, screws, and conductive materials.
  • Keep the SHT41 at an airflow-exposed edge, thermally isolated from the MCU, buck regulator, inductor, USB-C connector, and LED.
  • Keep the buck power loop compact and away from both the sensor and antenna.
  • Place USB-C protection directly behind the connector and decoupling capacitors beside their associated pins.
  • Run placement DRC, then confirm placement before routing.
Recommend board setup
Define antenna keepout
Create placement checklist
Check placement constraints
SW1
SW2
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USB-C WiFi BLE TH Sensor

USB-C WiFi BLE TH Sensor thumbnail
Consumer USB-C powered environmental sensor node with Wi-Fi, BLE 5.x, digital temperature/humidity sensing, protected 5 V input, and a 3.3 V low-power MCU/sensor rail.

Properties

WiFi

USB-C

Consumer IoT

5

V

Bluetooth

Pricing & Availability

Distributor

Qty 1

Arrow

$4.10–$6.66

Digi-Key

$0.00

HQonline

$3.72–$3.82

LCSC

$5.53–$5.70

Mouser

$26.70

TME

$0.40

Verical

$5.60–$8.33

Controls