# USB-C WiFi BLE Environmental Sensor
## Description
Consumer USB-C powered low-power environmental sensor node with digital temperature/humidity sensing, ESP32-class Wi-Fi/BLE 5.x connectivity, and protected 5V USB-C input for 0.5–3A sources.
## Project Details
- **Owner:** inar
- **Created:** 5/26/2026
- **Last Updated:** 5/26/2026
- **Visibility:** Public
## Key Components
### D1 — [USBLC6-4SC6](https://www.flux.ai/kicad-part-library/usblc6-4sc6~cr3.md)
- Part Type: Protection
- Datasheet URL: https://www.st.com/resource/en/datasheet/usblc6-4.pdf
- Manufacturer Name: Texas Instruments Inc.
- Role: Protection
- Package or Case Code: SOT-23-6
- Manufacturer Part Number: USBLC6-4SC6
- Role Details: ESD clamp for USB-C data and VBUS-adjacent exposed connector lines.
**Pins:**
- GND [pin 2]
- I/O1 [pin 1]
- I/O2 [pin 3]
- I/O3 [pin 4]
- I/O4 [pin 6]
- VBUS [pin 5]
### D2 — [Generic LED SMD](https://www.flux.ai/jharwinbarrozo/generic-led-smd~ku.md)
- Part Type: LED
- Role Details: Firmware-controlled low-current status indicator.
- Package: LED_0603_1608Metric
- Role: Signal Generation
**Pins:**
- A [pin 2]
- K [pin 1]
### J1 — [USB-C 2.0 Receptacle](https://www.flux.ai/vasy_skral/usb-c-2p0-receptacle~1xw.md)
- Role: Power Filtering
- Manufacturer Name: GTC
- Part Type: USB C
- Manufacturer Part Number: USB4105-GF-A
- Symbol Style: parametric-v1
- Datasheet URL: https://gct.co/files/drawings/usb4105.pdf
- Role Details: USB-C 5V default sink input and native USB data path to MCU.
- Purchase Url: https://www.digikey.com/en/products/detail/gct/USB4105-GF-A/11198441
**Pins:**
- CC1 [pin 6]
- CC2 [pin 12]
- D- [pin 7]
- D- [pin 9]
- D+ [pin 10]
- D+ [pin 8]
- GND [pin 1]
- GND [pin 16]
- GND [pin 15]
- GND [pin 2]
- SBU1 [pin 11]
- SBU2 [pin 5]
- VBUS [pin 3]
- VBUS [pin 14]
- VBUS [pin 4]
- VBUS [pin 13]
### SW1 — [Tactile Switch SPST-NO PTS526 SK15 SMTR2 LFS](https://www.flux.ai/collinsemasi/tactile-switch-spst-no-pts526-sk15-smtr2-lfs~83.md)
- Role Details: Manual reset button pulls MCU EN low.
- Role: Switching
- Manufacturer Part Number: PTS526 SK15 SMTR2 LFS
- Datasheet URL: https://www.ckswitches.com/media/2780/pts526.pdf
- Part Type: Switch
- Manufacturer Name: C&K
**Pins:**
- 2 [pin 2]
- 4 [pin 4]
- 1 [pin 1]
- 3 [pin 3]
### SW2 — [Tactile Switch SPST-NO PTS526 SK15 SMTR2 LFS](https://www.flux.ai/collinsemasi/tactile-switch-spst-no-pts526-sk15-smtr2-lfs~83.md)
- Role: Switching
- Part Type: Switch
- Role Details: Manual boot/download button pulls GPIO9/BOOT low during reset.
- Manufacturer Name: C&K
- Manufacturer Part Number: PTS526 SK15 SMTR2 LFS
- Datasheet URL: https://www.ckswitches.com/media/2780/pts526.pdf
**Pins:**
- 2 [pin 2]
- 4 [pin 4]
- 1 [pin 1]
- 3 [pin 3]
### U1 — [ESP32-C3-WROOM-02-N4](https://www.flux.ai/adrian95/esp32-c3-wroom-02-n4~gwb.md)
- Symbol Style: parametric-v1
- Datasheet URL: https://www.espressif.com/sites/default/files/documentation/esp32-c3-wroom-02_datasheet_en.pdf
- Role Details: Main MCU with 2.4GHz Wi-Fi 802.11 b/g/n and BLE 5.x for the environmental node.
- Manufacturer Part Number: ESP32-C3-WROOM-02-N4
- Role: Modulation / Demodulation
- Part Type: Module
- License: https://creativecommons.org/licenses/by/4.0/
- Manufacturer Name: Espressif Systems
**Pins:**
- 3V3 [pin 1]
- EN [pin 2]
- GND_1 [pin 9]
- GND_10 [pin 27]
- GND_2 [pin 19]
- GND_3 [pin 20]
- GND_4 [pin 21]
- GND_5 [pin 22]
- GND_6 [pin 23]
- GND_7 [pin 24]
- GND_8 [pin 25]
- GND_9 [pin 26]
- IO0 [pin 18]
- IO1 [pin 17]
- IO10 [pin 10]
- IO18 [pin 13]
- IO19 [pin 14]
- IO2 [pin 16]
- IO3 [pin 15]
- IO4 [pin 3]
- IO5 [pin 4]
- IO6 [pin 5]
- IO7 [pin 6]
- IO8 [pin 7]
- IO9 [pin 8]
- RXD [pin 11]
- TXD [pin 12]
### U2 — [SHT41-AD1B-R3](https://www.flux.ai/adrian95/sht41-ad1b-r3~bec.md)
- Datasheet URL: https://sensirion.com/media/documents/33FD6951/67EB9032/HT_DS_Datasheet_SHT4x_5.pdf
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Sensors
- Manufacturer Name: Sensirion
- Role: Sensing (Shunt)
- Manufacturer Part Number: SHT41-AD1B-R3
- Role Details: I2C temperature and relative humidity measurement sensor placed away from heat sources.
**Pins:**
- SCL [pin 2]
- SDA [pin 1]
- VDD [pin 3]
- VSS [pin 4]
### U3 — [TPS259530DSGR](https://www.flux.ai/lcsc/tps259530dsgr~9ds.md)
- Role: Protection
- Manufacturer Part Number: TPS259530DSGR
- Manufacturer Name: Texas Instruments
- Role Details: USB-C VBUS eFuse sized from 600mA peak load target, with current limit configured near 1A for 0.5–3A source compatibility.
- Datasheet URL: https://www.ti.com/lit/ds/symlink/tps2595.pdf
- LCSC Part Number: C2155775
- JLCPCB Part Class: Extended Part
- Part Type: Integrated Circuit
- Package or Case Code: WSON-8_L2.0-W2.0-P0.50-TL-EP
**Pins:**
- ~{FLT} [pin 6]
- dVdt [pin 1]
- EN/UVLO [pin 2]
- EP [pin 9]
- GND [pin 8]
- ILM [pin 7]
- IN [pin 3]
- IN [pin 4]
- OUT [pin 5]
### U4 — [AP63203WU-7](https://www.flux.ai/adrian95/ap63203wu-7~o8a.md)
- Manufacturer Part Number: AP63203WU-7
- Manufacturer Name: Diodes Incorporated
- Datasheet URL: https://www.diodes.com/assets/Datasheets/AP63200-AP63201-AP63203-AP63205.pdf
- Role Details: Fixed 3.3V buck regulator selected to avoid feedback divider and provide >600mA ESP32 peak-current margin.
- Role: Power Conversion
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Integrated Circuit
**Pins:**
- BST [pin 6]
- EN [pin 2]
- FB [pin 1]
- GND [pin 4]
- SW [pin 5]
- VIN [pin 3]
*The full schematic, PCB layout, bill of materials, and interactive design are available at [https://www.flux.ai/inar/usb-c-wifi-ble-environmental-sensor~8m](https://www.flux.ai/inar/usb-c-wifi-ble-environmental-sensor~8m).*
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*Generated from [https://www.flux.ai/inar/usb-c-wifi-ble-environmental-sensor~8m](https://www.flux.ai/inar/usb-c-wifi-ble-environmental-sensor~8m)*