USB-C Temp/Humidity Sensor Design

flux

I’ll build the schematic for a USB‑C powered Wi‑Fi/BLE environmental sensor node: select the MCU/sensor/protection/regulator parts, calculate the power path sizing, wire the circuit with required passives, add project/firmware notes, then run review checks and fix issues.

flux

I selected an ESP32-C3 module, SHT40 sensor, USB-C receptacle, TPS2595-class eFuse, 3.3 V buck regulator, USB ESD, buttons, LED, and generic support passives. I’m checking the active-part datasheets now so the schematic values and wiring follow the recommended circuits.

flux

Done — I created the schematic for the USB‑C powered Wi‑Fi/BLE temperature/humidity sensor node, including protected 5 V input, 3.3 V buck regulation, ESP32‑C3 module, SHT40 I2C sensor, USB data ESD, boot/reset buttons, status LED, and required decoupling/pull resistors.
I also added project files for the power/design notes, firmware starter, and review results. The schematic/ERC checks are clean; remaining full-review errors are expected because the board is not placed/routed yet and generic passives still need production MPNs before manufacturing.
Next checkpoint: I’m ready to move from schematic to layout — size the board, place components with the ESP32 antenna at the edge, then route after placement approval. Want me to proceed with layout?
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Project Specification
Design Summary
Status: Draft / Review / Approved
Manufacturing target: Prototype / EVT / DVT / PVT / Production
Software / firmware: repository link
Scope
Purpose
In scope
Out of scope
System context
Requirements
Functional
Electrical
Mechanical / environmental
Key constraints
Dependencies and risks
Dependencies
Key risks
Validation
Success criteria
Planned checks
Release-facing notes
Expected deliverables
Special release notes
Change notes / open questions
Changes in this revision
Open questions

    Design Summary

    Scope

    System context

    Requirements

    Functional

    Electrical

    Mechanical / environmental

    Key constraints

    Dependencies and risks

    Validation

    Release-facing notes

    Change notes / open questions

Documents

    Project Specification

    Design Notes — USB-C WiFi BLE Temperature/Humidity Sensor Node

    Firmware Starter — ESP32-C3-MINI-1-N4

    Design Review Results — Schematic Phase

Assets

No assets added.

USB-C WiFi BLE Temperature Humidity Sensor Node

USB-C WiFi BLE Temperature Humidity Sensor Node thumbnail
Low-power consumer environmental sensor node powered from USB-C 5 V, using Wi-Fi/BLE and a digital temperature/humidity sensor with protected 5 V input and 3.3 V electronics.

Properties

5

V

ESP32 Arduino / PlatformIO starter firmware

Digital I2C temperature/humidity sensor, ESP32-C3/S3-class Wi-Fi/BLE module, protected USB-C VBUS path, 3.3 V rail, decoupling and boot/reset support circuitry

2.4 GHz Wi-Fi 802.11 b/g/n and Bluetooth Low Energy 5.x

Consumer electronics / environmental sensing

USB-C 5 V sink, default Type-C current, designed for 0.5–3 A source capability with onboard OVP/UVLO/OCP/reverse-current protection

Pricing & Availability

Distributor

Qty 1

Arrow

$2.12–$2.61

Digi-Key

$3.76–$5.88

HQonline

$2.59

LCSC

$11.83

Mouser

$5.33

TME

$4.25

Verical

$2.72–$5.63

Controls