Temperature and Humidity Sensor Node Design

flux

I continued until ACUs became unavailable. Completed: renamed/described the project, selected the architecture and parts, built the schematic with USB‑C input, TPS2595 eFuse protection, MP28301 3.3 V buck, ESP32‑C3 Wi‑Fi/BLE module, SHT41 sensor, USB data ESD, boot/reset, status LED, and created project files for the spec, power budget, firmware starter, bring-up plan, and regulatory notes.
Remaining work:
  • Re-run ERC after the last cleanup step and resolve any remaining warnings.
  • Confirm no-connect markings were applied for unused ESP32/J1 pins.
  • Perform PCB placement/routing, especially ESP32 antenna keepout, buck layout, USB routing, and sensor thermal isolation.
  • Run DRC/airwire checks after layout.
  • Validate final TPS2595/MP28301 settings against datasheets before manufacturing.
A

angierg27

continue

flux

I’ll inspect the current schematic and project docs, run design checks, then fix any schematic issues I find before summarizing what remains for layout.

flux

I’m blocked because the account has no available ACUs, so I can’t continue AI layout actions right now.
Completed this session:
  • Verified the schematic/ERC state: no open errors or warnings were reported.
  • Set up the PCB as a 45 mm × 30 mm rounded rectangle with a standard 4-layer stackup and 0.5 mm board keepout.
  • Confirmed the board area is workable, though routing may be tight around the ESP32/power section.
Remaining work:
  • Place components with ESP32 antenna keepout, USB-C edge placement, compact buck/eFuse layout, and isolated SHT41 placement.
  • Route the PCB.
  • Run DRC and airwire checks.
  • Fix any routing or layout violations before manufacturing export.
Review placement constraints
Check ACU balance
Run layout checks
Estimate board size
Sign up to send

Files

Schematic

Layout

Preview

Technical Construction File — USB-C WiFi BLE Environmental Sensor Node
Status
Draft.
Applicable Areas
  • FCC Part 15 / intentional radiator and unintentional radiator considerations.
  • CE RED / EMC / RoHS / REACH considerations for EU sales.
  • ISED/UKCA as needed by target market.
Wireless Technology Summary

Table

ModuleMPNTechnologyFrequency bandNotes
U1ESP32-C3-WROOM-02-N4Wi-Fi 802.11 b/g/n + BLE 5.x2.4 GHz ISMUse module antenna keepout and integration rules.
Produced Project Files
  • Project specification: requirements and block-level decisions.
  • Power budget and design notes: power-path decisions and current-limit strategy.
  • Firmware starter: initial firmware and pin map.
  • Board bring-up plan: first-article validation procedure.
RF Integration Notes
  • Place module antenna at board edge with no copper/components in the antenna keepout on any layer.
  • Preserve module ground/antenna recommendations and do not change antenna type.
  • Final enclosure material and nearby metal must be evaluated for RF detuning.
Consumer Product Notes
  • If using USB logos, confirm USB-IF requirements.
  • Include labeling/user manual statements required by the selected module grant and target market.
  • Plan EMC testing on the complete product, especially due to buck regulator and USB cable emissions.
  • Implement secure provisioning, signed OTA updates, credential protection, and factory reset behavior.
Open Items Requiring External Evidence
  • Final PCB layout/Gerbers.
  • Module grant/certification evidence and exact labeling statements.
  • Accredited EMC/RF test reports.
  • Final user manual and Declaration of Conformity signed by TechSpec.

  • Status

  • Applicable Areas

  • Wireless Technology Summary

  • Produced Project Files

  • RF Integration Notes

  • Consumer Product Notes

  • Open Items Requiring External Evidence