circuits

Room Sensor PCB

A compact ESP32-S3–based room sensor board integrating multiple environmental and motion sensors, addressable RGB LEDs, USB‑C connectivity, and regulated 3.3 V power.

Core MCU & Buttons

• MCU: ESP32‑S3‑WROOM‑1 (U201)
  • Dual‑core Xtensa with Wi‑Fi + BLE
  • Native USB for programming and CDC
  • Serial port header for debuging
• Buttons (SW201, SW202): Boot/Mode and Reset

Sensors

• Digital MEMS Microphone – ICS‑43434 (U1001) (C5656610)
  • Interface: I2S (WS/LRCLK, SCK/BCLK, SD/DOUT)
• 3‑Axis Accelerometer – LIS2DH (LIS2DHTR) (U1201) (C155670)
  • Interface: I2C
• Environmental Sensor – BME280 (U301)
  • Interface: I2C (temperature, humidity, pressure)
• Ambient Light Sensor – OPT3001 (U2002) (C90462)
  • Interface: I2C (lux)
• PIR Motion Sensor – EKMC1601112 (U2001) (C5128270)
  • Interface: Digital output to MCU GPIO

Addressable RGB LEDs

• 36× WS2812B‑compatible RGB LEDs (1.6×1.5 mm) (LED1401…LED1906) (C41413180 lcsc)
  • Part: XL‑1615RGBC‑WS2812B‑S
  • Daisy‑chained single‑wire data from MCU; power and ground in common

Notes:

• Budget up to ~60 mA per LED at full‑white (worst case). 36 LEDs ⇒ up to ~2.16 A at the LED supply voltage

Power

• USB-A PCB
  • Insert the sensor directly into a USB wall adapter with a separate cable.
• 3.3 V LDO Regulator – TPS73733DCQ (U501) (C5220270)
  • Provides regulated 3.3 V rail for MCU and sensors
• Primary Input: USB‑C Receptacle – TYPE‑C‑31‑M‑12 (USBC701) (C165948 )
  • Power input and USB data to ESP32‑S3
• USB ESD Protection – USBLC6‑2SC6 (U701, U801)
  • ESD protection for USB D+ / D− lines

I2C Inputs

• 5V, level-shifted internally to 3v3
• qwiic Compatible
• JST‑SH 1.0 mm, 4‑pin – SM04B‑SRSS‑TB (CN1102, CN601) (C160390)

Onewire temperature input

• JST‑SH 1.0 mm, 3‑pin – SM03B‑SRSS‑TB (U1301) (C160403)