USB-C Temp/Humidity Sensor Design

flux

0:16

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

2:30

Created 10 tasks.

1/10 Rename project and set consumer sensor-node metadata

2/10 Create project specification and design notes with power budget

Read schematic.

3/10 Select library parts for MCU, T/RH sensor, USB-C, protection, regulator, buttons, LED

Thought for 17 sec

No results for Find an ESP32-C3 or ESP32-S3 module for a low-power consumer USB-C temperature/humidity sensor node. Needs 2.4 GHz Wi-Fi 802.11 b/g/n, BLE 5.x, native USB preferred, castellated/SMD module with antenna, available in Flux library. Return a part suitable to add to schematic..

Found 3 results for Find a low-power digital temperature and relative humidity sensor for a 3.3 V I2C environmental node, preferably Sensirion SHT40 or SHT41, small DFN package, available in Flux library..

Found 3 results for Find a USB Type-C receptacle for a USB 2.0 device/sink powered from 5 V default Type-C current. Needs CC1/CC2 pins, VBUS, GND, D+/D-, SMD footprint, consumer product use, available in Flux library..

Found 3 results for Find a USB VBUS protection eFuse or load switch for 5 V input with overvoltage protection, undervoltage lockout, overcurrent/current limit, reverse current blocking or reverse protection, suitable for 0.5 A to 3 A capable USB-C sources..

Found 3 results for Find a low quiescent current 3.3 V buck regulator for 5 V USB input and ESP32-class Wi-Fi/BLE load, at least 600 mA preferably 1 A output current, with datasheet and footprint available in Flux library..

Thought for 4 sec

Found 10 results for ESP32-C3-MINI-1.

Found 10 results for ESP32-S3-WROOM-1.

Found 10 results for TPS25921.

Found 10 results for TPS2595.

Found 10 results for TPS2553.

Found 5 results for TPD2EUSB30.

Found 5 results for USBLC6-2.

Found 5 results for TPD2E2U06.

Found 3 results for Generic Resistor.

Found 3 results for Generic Capacitor.

Found 3 results for Generic Inductor.

Found 5 results for LED 0603 green.

Found 2 results for tactile switch SMD 4 pin.

Thought for 3 sec

Found 5 results for AP63203WU-7.

Found 9 results for AP63203.

Found 1 results for TPS62162 3.3V.

4/10 Consult datasheets for active/protection/regulator parts before wiring

Read 11 knowledge entries.

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

8:26

Read ESP32-C3-MINI-1-N4 datasheet for pin description power supply pins USB Se.

Read SHT40-AD1B-R2 datasheet for pin assignment recommended operating con.

Read TPS259530DSGR datasheet for typical application current limit overvo.

Read AP63203WU-7 datasheet for typical application circuit fixed 3.3V i.

Read USB4215-03-A datasheet for pinout VBUS GND CC1 CC2 D+ D- shell pins.

Read TPD2E2U06DRLR datasheet for pin configuration USB D+ D- ESD protecti.

Read PTS636 SM43J SMTR LFS datasheet for pin configuration SPST normally open swi.

Read SML-D13FWT86C datasheet for forward voltage forward current polarity.

Thought for 2 sec

Found 1 results for Sensirion SHT40 datasheet pinout VDD SDA SCL decoupling capacitor I2C pull-up.

Found 1 results for TI TPS259530 datasheet typical application ILIM dVdt overvoltage undervoltage capacitors.

Read schematic.

Thought for 6 sec

Thought for 3 sec

9/10 Create firmware starter project file grounded in schematic pin mapping

10/10 Run ERC/review, fix real violations, and re-validate

Completed 9 design checks — found 75 issues.

Thought for 3 sec

Completed design checks — found 75 issues.

Thought for 25 sec

10/10 tasks completed.

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?
Set board size
Auto-place components
Add passive MPNs
Check blocking issues

Finished working

Sign up to send
  • Generic Inductor
    Generic Inductor
    A generic fixed inductor suitable for rapid circuit topology development. The footprint automatically adapts based on the selected package, supporting standard SMD sizes (e.g., 0402, 0603, 0805) as well as well-known inductor packages such as SDR1806, PA4320, SRN6028, and SRR1260. Standard inductor values: 1.0 nH, 10 nH, 100 nH, 1.0 µH, 10 µH, 100 µH, 1.0 mH 1.2 nH, 12 nH, 120 nH, 1.2 µH, 12 µH, 120 µH, 1.2 mH 1.5 nH, 15 nH, 150 nH, 1.5 µH, 15 µH, 150 µH, 1.5 mH 1.8 nH, 18 nH, 180 nH, 1.8 µH, 18 µH, 180 µH, 1.8 mH 2.2 nH, 22 nH, 220 nH, 2.2 µH, 22 µH, 220 µH, 2.2 mH 2.7 nH, 27 nH, 270 nH, 2.7 µH, 27 µH, 270 µH, 2.7 mH 3.3 nH, 33 nH, 330 nH, 3.3 µH, 33 µH, 330 µH, 3.3 mH 3.9 nH, 39 nH, 390 nH, 3.9 µH, 39 µH, 390 µH, 3.9 mH 4.7 nH, 47 nH, 470 nH, 4.7 µH, 47 µH, 470 µH, 4.7 mH 5.6 nH, 56 nH, 560 nH, 5.6 µH, 56 µH, 560 µH, 5.6 mH 6.8 nH, 68 nH, 680 nH, 6.8 µH, 68 µH, 680 µH, 6.8 mH 8.2 nH, 82 nH, 820 nH, 8.2 µH, 82 µH, 820 µH, 8.2 mH #generics #CommonPartsLibrary
    jharwinbarrozo
    16.0k
  • Generic Capacitor
    Generic Capacitor
    A generic fixed capacitor ideal for rapid circuit topology development. You can choose between polarized and non-polarized types, its symbol and the footprint will automatically adapt based on your selection. Supported options include standard SMD sizes for ceramic capacitors (e.g., 0402, 0603, 0805), SMD sizes for aluminum electrolytic capacitors, and through-hole footprints for polarized capacitors. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard capacitor values: 1.0pF, 10pF, 100pF, 1000pF, 0.01uF, 0.1uF, 1.0uF, 10uF, 100uF, 1000uF, 10000uF 1.1pF, 11pF, 110pF, 1100pF 1.2pF, 12pF, 120pF, 1200pF 1.3pF, 13pF, 130pF, 1300pF 1.5pF, 15pF, 150pF, 1500pF, 0.015uF, 0.15uF, 1.5uF, 15uF, 150uF, 1500uF 1.6pF, 16pF, 160pF, 1600pF 1.8pF, 18pF, 180pF, 1800pF 2.0pF, 20pF, 200pF, 2000pF 2.2pF, 22pF, 220pF, 2200pF, 0.022uF, 0.22uF, 2.2uF, 22uF, 220uF, 2200uF 2.4pF, 24pF, 240pF, 2400pF 2.7pF, 27pF, 270pF, 2700pF 3.0pF, 30pF, 300pF, 3000pF 3.3pF, 33pF, 330pF, 3300pF, 0.033uF, 0.33uF, 3.3uF, 33uF, 330uF, 3300uF 3.6pF, 36pF, 360pF, 3600pF 3.9pF, 39pF, 390pF, 3900pF 4.3pF, 43pF, 430pF, 4300pF 4.7pF, 47pF, 470pF, 4700pF, 0.047uF, 0.47uF, 4.7uF, 47uF, 470uF, 4700uF 5.1pF, 51pF, 510pF, 5100pF 5.6pF, 56pF, 560pF, 5600pF 6.2pF, 62pF, 620pF, 6200pF 6.8pF, 68pF, 680pF, 6800pF, 0.068uF, 0.68uF, 6.8uF, 68uF, 680uF, 6800uF 7.5pF, 75pF, 750pF, 7500pF 8.2pF, 82pF, 820pF, 8200pF 9.1pF, 91pF, 910pF, 9100pF #generics #CommonPartsLibrary
    jharwinbarrozo
    1.5M
  • Generic Resistor
    Generic Resistor
    A generic fixed resistor ideal for rapid circuit topology development. Its footprint automatically adapts based on the selected package case code—supporting 0402, 0603, 0805, 1203, and many other standard SMD packages, as well as axial horizontal and vertical configurations. Save precious design time by seamlessly add more information to this part (value, footprint, etc.) as it becomes available. Standard resistor values: 1.0 ohm, 10 ohm, 100 ohm, 1.0k ohm, 10k ohm, 100k ohm, 1.0M ohm 1.1 ohm, 11 ohm, 110 ohm, 1.1k ohm, 11k ohm, 110k ohm, 1.1M ohm 1.2 ohm, 12 ohm, 120 ohm, 1.2k ohm, 12k ohm, 120k ohm, 1.2M ohm 1.3 ohm, 13 ohm, 130 ohm, 1.3k ohm, 13k ohm, 130k ohm, 1.3M ohm 1.5 ohm, 15 ohm, 150 ohm, 1.5k ohm, 15k ohm, 150k ohm, 1.5M ohm 1.6 ohm, 16 ohm, 160 ohm, 1.6k ohm, 16k ohm, 160k ohm, 1.6M ohm 1.8 ohm, 18 ohm, 180 ohm, 1.8K ohm, 18k ohm, 180k ohm, 1.8M ohm 2.0 ohm, 20 ohm, 200 ohm, 2.0k ohm, 20k ohm, 200k ohm, 2.0M ohm 2.2 ohm, 22 ohm, 220 ohm, 2.2k ohm, 22k ohm, 220k ohm, 2.2M ohm 2.4 ohm, 24 ohm, 240 ohm, 2.4k ohm, 24k ohm, 240k ohm, 2.4M ohm 2.7 ohm, 27 ohm, 270 ohm, 2.7k ohm, 27k ohm, 270k ohm, 2.7M ohm 3.0 ohm, 30 ohm, 300 ohm, 3.0K ohm, 30K ohm, 300K ohm, 3.0M ohm 3.3 ohm, 33 ohm, 330 ohm, 3.3k ohm, 33k ohm, 330k ohm, 3.3M ohm 3.6 ohm, 36 ohm, 360 ohm, 3.6k ohm, 36k ohm, 360k ohm, 3.6M ohm 3.9 ohm, 39 ohm, 390 ohm, 3.9k ohm, 39k ohm, 390k ohm, 3.9M ohm 4.3 ohm, 43 ohm, 430 ohm, 4.3k ohm, 43K ohm, 430K ohm, 4.3M ohm 4.7 ohm, 47 ohm, 470 ohm, 4.7k ohm, 47k ohm, 470k ohm, 4.7M ohm 5.1 ohm, 51 ohm, 510 ohm, 5.1k ohm, 51k ohm, 510k ohm, 5.1M ohm 5.6 ohm, 56 ohm, 560 ohm, 5.6k ohm, 56k ohm, 560k ohm, 5.6M ohm 6.2 ohm, 62 ohm, 620 ohm, 6.2k ohm, 62K ohm, 620K ohm, 6.2M ohm 6.8 ohm, 68 ohm, 680 ohm, 6.8k ohm, 68k ohm, 680k ohm, 6.8M ohm 7.5 ohm, 75 ohm, 750 ohm, 7.5k ohm, 75k ohm, 750k ohm, 7.5M ohm 8.2 ohm, 82 ohm, 820 ohm, 8.2k ohm, 82k ohm, 820k ohm, 8.2M ohm 9.1 ohm, 91 ohm, 910 ohm, 9.1k ohm, 91k ohm, 910k ohm, 9.1M ohm #generics #CommonPartsLibrary
    jharwinbarrozo
    1.5M
  • Ground
    Ground
    A common return path for electric current. Commonly known as ground.
    jharwinbarrozo
    20.5M
  • Terminal
    Terminal
    An electrical connector acting as reusable interface to a conductor and creating a point where external circuits can be connected.
    natarius
  • Net Portal
    Net Portal
    Wirelessly connects nets on schematic. Used to organize schematics and separate functional blocks. To wirelessly connect net portals, give them same designator. #portal
    jharwinbarrozo
    43.0M
  • RMCF0805JT47K0
    RMCF0805JT47K0
    General Purpose Thick Film Standard Power and High-Power Chip Resistor 47 kOhms ±5% 0.125W, 1/8W Chip Resistor 0805 (2012 Metric) Automotive AEC-Q200 Thick Film Features: - RMCF – standard power ratings - RMCP – high power ratings - Nickel barrier terminations standard - Power derating from 100% at 70ºC to zero at +155ºC - RoHS compliant, REACH compliant, and halogen free - AEC-Q200 compliant
    jharwinbarrozo
    1.2M
  • 875105359001
    875105359001
    10 µF 16 V Aluminum - Polymer Capacitors Radial, Can - SMD 30mOhm 2000 Hrs @ 105°C #commonpartslibrary #capacitor #aluminumpolymer #radialcan
    jharwinbarrozo
    1.2M
  • CTL1206FYW1T
    CTL1206FYW1T
    Yellow 595nm LED Indication - Discrete 1.7V 1206 (3216 Metric)
    jharwinbarrozo
    1.1M
  • 1070TR
    1070TR
    Battery Holder (Open) Coin, 20.0mm 1 Cell SMD (SMT) Tab bate or batt #forLedBlink
    jharwinbarrozo
    700.5k

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