# Compulsory Yellow KITT
## Description
5V Wi-Fi/BLE Humidity Sensor with ESP32-WROOM-32, SHTC3, and AP63203WU-7 Buck Regulator
## Project Details
- **Owner:** oozliuoo
- **Created:** 10/6/2025
- **Last Updated:** 10/6/2025
- **Visibility:** Public
- **System Architecture:** ```mermaid
graph LR
P5V["5V Input"] --> LDO["3.3V LDO Regulator"]
LDO --> ESP["ESP32-WROOM-32"]
LDO --> SHTC3["SHTC3 Sensor"]
ESP -->|I2C| SHTC3
ESP -->|Wi-Fi/BLE| Cloud["Cloud Backend"]
```
## Key Components
### J1 — [PJ-037A](https://www.flux.ai/vasy_skral/pj-037a~6cq.md)
- Role Details: 2.1 mm barrel power jack for 5V input
- Role: Interface
- Footprint: CUI_PJ-037A
- Manufacturer Name: CUI Devices
- Part Type: Connector
- Datasheet URL: https://www.cuidevices.com/product/resource/pj-037a.pdf
- Manufacturer Part Number: PJ-037A
**Pins:**
- Center pin [pin 1]
- Terminal [pin 2]
### U1 — [ESP32-WROOM-32D](https://www.flux.ai/vasyl/esp32-wroom-32d~7py.md)
- Part Type: Microcontroller
- Manufacturer Name: Espressif
- Role: Main MCU
- License: https://creativecommons.org/licenses/by/4.0/
- Datasheet URL: https://www.espressif.com/sites/default/files/documentation/esp32-wroom-32d_esp32-wroom-32u_datasheet_en.pdf
- Footprint: Espressif_ESP32-WROOM-32
- Role Details: Wi-Fi/Bluetooth microcontroller
- Manufacturer Part Number: ESP32-WROOM-32
**Pins:**
- 3.3V [pin 2]
- AGND [pin 39]
- CLK [pin 20]
- CMD [pin 19]
- EN [pin 3]
- GND [pin 38]
- GND [pin 15]
- GND [pin 1]
- IO0 [pin 25]
- IO12 [pin 14]
- IO13 [pin 16]
- IO14 [pin 13]
- IO15 [pin 23]
- IO16 [pin 27]
- IO17 [pin 28]
- IO18 [pin 30]
- IO19 [pin 31]
- IO2 [pin 24]
- IO21 [pin 33]
- IO22 [pin 36]
- IO23 [pin 37]
- IO25 [pin 10]
- IO26 [pin 11]
- IO27 [pin 12]
- IO32 [pin 8]
- IO33 [pin 9]
- IO34 [pin 6]
- IO35 [pin 7]
- IO4 [pin 26]
- IO5 [pin 29]
- NC [pin 32]
- RXD0 [pin 34]
- SD0 [pin 21]
- SD1 [pin 22]
- SD2 [pin 17]
- SD3 [pin 18]
- TXD0 [pin 35]
- VN [pin 5]
- VP [pin 4]
### U2 — [SHTC3-TR-2.5KS](https://www.flux.ai/adrian95/shtc3-tr-2p5ks~af.md)
- Manufacturer Part Number: SHTC3-TR-2.5KS
- Role: Sensing (Shunt)
- Manufacturer Name: Sensirion AG
- Datasheet URL: https://mm.digikey.com/Volume0/opasdata/d220001/medias/docus/906/HT_DS_SHTC3_D1.pdf
- Footprint: Sensirion_SHTC3-TR-2.5KS
- License: https://creativecommons.org/licenses/by/4.0/
- Part Type: Sensor
- Role Details: I2C humidity & temperature sensor
**Pins:**
- EPAD [pin 5]
- SCL [pin 2]
- SDA [pin 3]
- VDD [pin 1]
- VSS [pin 4]
### U3 — [AP63203WU-7](https://www.flux.ai/adrian95/ap63203wu-7~o8a.md)
- Manufacturer Part Number: AP63203WU-7
- Role: Power Conversion
- License: https://creativecommons.org/licenses/by/4.0/
- Footprint: Diodes_Incorporated_AP63203WU-7
- Manufacturer Name: Diodes Incorporated
- Role Details: 5 V to 3.3 V buck regulator
- Datasheet URL: https://www.diodes.com/assets/Datasheets/AP63200-AP63201-AP63203-AP63205.pdf
- 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/oozliuoo/compulsory-yellow-kitt~cz](https://www.flux.ai/oozliuoo/compulsory-yellow-kitt~cz).*
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*Generated from [https://www.flux.ai/oozliuoo/compulsory-yellow-kitt~cz](https://www.flux.ai/oozliuoo/compulsory-yellow-kitt~cz)*