USB Sensor Node PCB


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.
I can’t run analysis or auto-layout right now because the account has no available ACUs, so AI execution features are unavailable.
Current project state:
  • Schematic has been built for the USB-C WiFi/BLE temperature/humidity sensor node.
  • Key blocks are present: USB-C input, ESD protection, TPS25940 eFuse/protection, MP28301 3.3 V buck regulator, SiWG917 Wi‑Fi/BLE module, SHT41 sensor, debug/reset/ISP controls, and status LED.
  • Supporting project files were created: specification, firmware starter, bring-up plan, and regulatory/TCF notes.
What remains:
  • Inspect current PCB layout state to confirm whether placement, routing, or both are needed.
  • Run component placement with constraints: SiWG917 antenna at board edge, SHT41 away from heat sources, USB-C at edge, buck loop compact.
  • Route traces and resolve airwires.
  • Run DRC/ERC after layout and fix remaining issues.
  • Assign final MPNs to generic passives before manufacturing export.
Inspect layout state
Run ERC/DRC
Review BOM MPNs
Document constraints

U1

USB-C WiFi BLE TH Sensor

USB-C WiFi BLE TH Sensor thumbnail