R2 changes: -Moving to Letter Modules for ease of design -Adding ESP32 for WiFi On/Off and intensity control -Optional: Add unpopulated AA Battery Holder for battery option R1 changes: -Changed LED part to Red LEDs -adjusted resistor value of buck converter -Changed source for USB-C Connector -Removed exposed soldermask on buck converter with negative soldermask expansion -Order with black soldermask Modified by markwu2001: Adjustable Brightness, 85-90% Drive Efficiency <5W Operation (Can use 5V 1A Plug) This project can be purchased from LCSC Original Description: Daddy's second circuit board. A sign to let my wife know when I'm on a call. Activates with a slide switch and is powered by USB-C. #template

R1 changes: -Changed LED part to Red LEDs -adjusted resistor value of buck converter -Changed source for USB-C Connector -Removed exposed soldermask on buck converter with negative soldermask expansion -Order with black soldermask Modified by markwu2001: - Adjustable Brightness, - 85-90% Drive Efficiency - <5W Operation (Can use 5V 1A Plug) This project can be purchased from LCSC Original Description: Daddy's second circuit board. A sign to let my wife know when I'm on a call. Activates with a slide switch and is powered by USB-C.

R1 changes: -Changed LED part to Red LEDs -adjusted resistor value of buck converter -Changed source for USB-C Connector -Removed exposed soldermask on buck converter with negative soldermask expansion -Order with black soldermask Modified by markwu2001: - Adjustable Brightness, - 85-90% Drive Efficiency - <5W Operation (Can use 5V 1A Plug) This project can be purchased from LCSC Original Description: Daddy's second circuit board. A sign to let my wife know when I'm on a call. Activates with a slide switch and is powered by USB-C.

R2 changes: -Moving to Letter Modules for ease of design -Adding ESP32 for WiFi On/Off and intensity control -Optional: Add unpopulated AA Battery Holder for battery option R1 changes: -Changed LED part to Red LEDs -adjusted resistor value of buck converter -Changed source for USB-C Connector -Removed exposed soldermask on buck converter with negative soldermask expansion -Order with black soldermask Modified by markwu2001: - Adjustable Brightness, - 85-90% Drive Efficiency - <5W Operation (Can use 5V 1A Plug) This project can be purchased from LCSC Original Description: Daddy's second circuit board. A sign to let my wife know when I'm on a call. Activates with a slide switch and is powered by USB-C. #template

GCT_USB4105_REVA USB-C (USB TYPE-C) USB 2.0 Receptacle Connector 24 (16+8 Dummy) Position Surface Mount, Right Angle; Through Hole In Stock None Global Connector Technology None https://pricing.snapeda.com/search/part/USB4105/?ref=eda USB4105 Aliases: undefined

GCT_USB4105_REVA USB-C (USB TYPE-C) USB 2.0 Receptacle Connector 24 (16+8 Dummy) Position Surface Mount, Right Angle; Through Hole In Stock None Global Connector Technology None https://pricing.snapeda.com/search/part/USB4105/?ref=eda USB4105 Aliases: undefined

Architectural Lavender Translation Collar – ESP32‑S3 Wi‑Fi + LoRa, USB‑C, Li‑ion, low‑power design Overview Experience a cutting-edge IoT solution with this low‑power board built around the ESP32‑S3‑MINI‑1‑N8. Designed for seamless Wi‑Fi (2.4 GHz), BLE, and LoRa (868 MHz) connectivity, this board integrates ENS161 and ENS210 sensors over I2C alongside an RFM95W‑868 LoRa radio on SPI. It is powered via a 3.7 V Li‑ion cell with USB‑C charging up to 500 mA, complete with full battery protection, a robust 3.3 V rail tailored for Wi‑Fi burst currents, and per‑peripheral power gating to enhance energy efficiency. Core Features • MCU: ESP32‑S3‑MINI‑1‑N8 equipped with an onboard PCB antenna for 2.4 GHz Wi‑Fi/BLE, ensuring optimal wireless performance. • Sensors: Integrated ENS161 and ENS210 sensors utilize a shared I2C bus with controllable 4.7 kΩ pull‑ups for streamlined communication. • LoRa Radio: The RFM95W‑868 module, connected via SPI, enables long‑range communication at 868 MHz. Power & USB‑C Connectivity • Battery: A reliable 3.7 V 1200 mAh Li‑ion battery connected via a right‑angle JST‑PH 2‑pin connector features built‑in battery protection. • Charging: The USB‑C receptacle, with CC resistors and TVS protection on D+/D− along with series resistors, supports fast, safe charging with a current limit of 500 mA. • Regulation: A dedicated 3.3 V regulator capable of handling Wi‑Fi burst currents coupled with bulk and high‑frequency decoupling ensures stable operation, supported by status LEDs indicating power and charge states. Low‑Power Control • Peripheral Management: Load switches allow selective power‑gating of the ENS161, ENS210, and RFM95W modules, controlled directly by ESP32‑S3 GPIOs. • Energy Efficiency: Controllable I2C pull‑ups minimize idle current, vital for prolonged battery life in IoT applications. RF and Antenna Integration • 2.4 GHz: Utilizes the integrated PCB antenna on the ESP32‑S3 with proper ground/metal keep‑out zones for optimal signal integrity. • 868 MHz: Features a controlled‑impedance feed from the RFM95W to a PI matching network (C‑L‑C pads) with flexible antenna options—selectable via SMA connector, chip antenna, or PCB trace—and includes RF ESD protection. Connectivity & Debug Features • USB‑C Interface: Provides secure data connectivity with integrated safeguards and proper terminations. • Debugging: A comprehensive programming/debug header exposes EN, BOOT, and UART lines, with test points on key rails and buses (3V3, VBAT, SCK, MOSI, MISO, SDA, SCL, RESET/EN, GND) to simplify development and troubleshooting. Design Verification • Rigorous ERC/DRC and decoupling checks ensure adherence to component ratings and optimal signal routing. • Maintain RF keep‑outs and impedance‑controlled traces for both 2.4 GHz and 868 MHz paths, securing reliable performance even during high‑intensity operations. #IoT #ESP32S3 #LoRa #LowPowerDesign #USB-C #WirelessConnectivity #BatteryPowered #RFDesign

The LoST 3296 board features an Low Power STM32, an RFM95 Module for LoRA connectivity and a connector to interface different sensors. You can hook up a UART module, I2C module and a module using the RS485. The board is powered by the USB-C port