USB C WiFi BLE Sensor Node
Worked for 7 mins 17 sec
Created 4 project docs
Design Notes — USB-C WiFi BLE Environmental Node
Input: USB-C receptacle J1, 5 V sink-only, USB 2.0 D+/D- routed to ESP32-C3 native USB Serial/JTAG. USB-C configuration: R1/R2 = 5.1 kΩ Rd f...
View docFirmware Starter — ESP32-C3-WROOM-02-N4
MCU/module: ESP32-C3-WROOM-02-N4 Framework: Arduino on PlatformIO
View docBoard Bring-Up Plan — USB-C WiFi BLE Environmental Node
Equipment: current-limited 5 V USB supply or USB power meter, multimeter, oscilloscope, USB-C cable, ESD-safe workstation, PlatformIO firmwa...
View docTechnical Construction File — USB-C WiFi BLE Environmental Node
Draft, schematic-stage. FCC Part 15 intentional radiator integration using pre-certified module conditions.
View docImplemented the schematic for the USB-C powered Wi‑Fi/BLE temperature/humidity node and created the supporting project files:
Open items:
- PCB layout has not been started yet; airwires are expected until placement/routing.
- Generic passives/testpoints still need production MPN assignment before manufacturing export.
- Layout must enforce ESP32 antenna keepout and keep the SHT40 away from heat sources.
Suggested next steps:
- Set board size/stackup and antenna/sensor placement constraints.
- Place components with the ESP32 antenna at the board edge.
- Route USB, buck power, and I2C nets.
- Assign production MPNs for generic passives and test pads.
Create layout constraints
Assign passive MPNs
Run schematic review
Start PCB placement
Prepare layout intent
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Technical Construction File — USB-C WiFi BLE Environmental Node
Status
Draft, schematic-stage.
Applicable Regulations
- FCC Part 15 intentional radiator integration using pre-certified module conditions.
- FCC Part 15B unintentional radiator testing for the final product.
- CE RED for EU wireless product placement.
- ISED/UKCA may apply depending on target markets.
- RoHS/REACH material compliance for consumer sale.
Product Description
USB-C powered consumer temperature and humidity node using an ESP32-C3-WROOM-02-N4 Wi-Fi/BLE module and SHT40 digital sensor.
Wireless Technology Summary
Table
| Module | MPN | Technology | Frequency Band | Antenna | Notes |
|---|---|---|---|---|---|
| U3 | ESP32-C3-WROOM-02-N4 | Wi-Fi 802.11 b/g/n + BLE 5.x | 2.4 GHz ISM | Integrated PCB antenna | Follow Espressif module integration and antenna keepout rules |
Required Documentation Checklist
- Project specification created.
- Schematic-stage BOM available in Flux.
- Firmware starter created.
- Bring-up/test plan created.
- Final PCB layout/Gerbers after placement/routing.
- RF module certificate/grant evidence attached for the exact ordered module variant.
- EMC/RF lab test reports for the finished product.
- Final user manual and product labels.
RF Design Notes
- Place U3 at a board edge with the ESP32-C3-WROOM-02 PCB antenna facing outward.
- Keep the antenna keepout free of copper, traces, vias, components, batteries, USB cable routing, and enclosure metal unless Espressif explicitly allows otherwise.
- Keep the buck converter, inductor, USB-C connector shell, and USB cable path away from the antenna area.
- Configure firmware regulatory domain/channel plan for the intended market.
EMC/ESD Notes
- D2 protects
VBUS_RAW; D1 protects USB D+/D−. Place both close to J1 with low-inductance ground return. - U2 buck layout is the primary conducted/radiated EMI risk. Keep SW loop compact and avoid routing SW near USB D+/D−, SHT40, and antenna.
- USB-C shield should be tied to board ground near the connector with stitching vias in the layout stage.
Draft Declaration of Conformity Placeholder
We, [Company Name], declare that the product USB-C WiFi BLE Environmental Node is designed for conformity with applicable FCC Part 15, CE RED, RoHS, and EMC requirements when manufactured and tested in its final enclosure.
Authorized signatory: ____________________
Date: ____________________
User Manual Safety/Compliance Outline
- Indoor use only unless enclosure is later rated for outdoor use.
- Use only compliant USB-C 5 V power sources.
- Do not cover or contaminate the humidity sensor opening.
- This device contains a 2.4 GHz Wi-Fi/Bluetooth radio module.
- Include required FCC/CE/ISED statements after module grant review and final product testing.
Open Items
- Attach exact Espressif certification documents for ESP32-C3-WROOM-02-N4.
- Complete PCB layout with antenna keepout and EMI controls.
- Perform pre-scan EMC/ESD testing before production release.
Status
Applicable Regulations
Product Description
Wireless Technology Summary
Required Documentation Checklist
RF Design Notes
EMC/ESD Notes
Draft Declaration of Conformity Placeholder
User Manual Safety/Compliance Outline
Open Items
