Compact 2S Li-ion charger for Sony NP-FZ100 battery using DC input, 8.4 V CC/CV charging, automatic termination, reverse polarity, overvoltage, overcurrent, and thermal protection, with defined B+ and B- battery outputs and PCB-buildable component choices.

FlowState Headband EVT1 — 4-Channel EEG Calibration Device Closed-loop EEG neurofeedback headband for theta/beta baseline calibration. 4-layer mixed-signal PCB, 40x30mm. Core ICs: - ADS1299-4PAG (TI) — 4-channel 24-bit EEG analog front end, SPI interface, 250 SPS - nRF5340 (Nordic) — Dual-core BLE 5.3 SoC, 128 MHz app core + 64 MHz network core Key requirements: - Separate analog and digital power domains (dual LDO: LP5907 for AVDD, AP2112 for DVDD) - Split analog/digital ground planes with single-point connection - 6 electrode inputs (4 active + 1 reference + 1 DRL) with individual TVS ESD protection on each - LIS2DH12 accelerometer (I2C) for motion artifact detection - MCP73831 USB-C battery charging (300-500 mAh LiPo) - 2.4 GHz chip antenna or PCB trace antenna at board edge with 10mm keepout - Conformal coating for sweat/moisture protection Reference designs: - Analog front-end: TI ADS1299 EVM (SBAS499) - Digital/BLE: Nordic nRF5340 DK reference schematic Critical constraint: Microvolt-level EEG signals — analog input routing and power supply filtering are the highest-priority layout concerns.

Industrial dual motor controller using an ESP8266 NodeMCU and L298N dual H-bridge for 2x 12V 2A DC motors, with MQTT remote control, manual override buttons, 5-bit DIP addressing, reset input, status LEDs, SS34 reverse-polarity protection, 5A fuse, LM2596 5V buck conversion, TVS surge protection, and future expansion provisions for INA219 current sensing, OTA firmware, RS485, and enclosure integration.

Single-channel 12-24V LED strip dimmer with ESP32-WROOM BLE control, hall pairing input, red status LED, and safe-fail 220VAC protection strategy

Production-defensible Rev B ear tag tracker using nRF9151 with separate LTE and GNSS antennas, solar-assisted LiPo charging, battery protection, SPI NOR flash, NFC, eSIM, I2C sensors, Tag-Connect SWD, grouped EVT test points, and RF/power zoning on a 40 mm x 24 mm 4-layer PCB.

Pi Zero 2 W Power HAT – 6 V Input, 5.2 V Buck to Pi 5 V Header via 1.85 A Fuse, Enhanced Input & Pi Rail Protection (TVS + High-Hold PTC + 5 A Schottky)

USB-C to SATA portable external hard drive enclosure controller. Architecture includes USB Type-C 5 V sink input with 5.1 kΩ CC pull-downs, VBUS ESD/TVS and overcurrent protection, USB 3.2 Gen1 SuperSpeed differential pairs into a USB-to-SATA bridge, SATA data and power output for a 2.5-inch drive, regulated 3.3 V logic rail with optional 1.8 V rail if required by the bridge, 25 MHz reference clock, power/activity LEDs, and test points. Design target is compact portable use with stable spin-up power delivery, low EMI, controlled-impedance high-speed routing, and production-grade BOM options.

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

Pi Zero 2 W Power HAT – 6 V Input, 5.2 V Buck to Pi 5 V Header via 1.85 A Fuse, Enhanced Input & Pi Rail Protection (TVS + High-Hold PTC + 5 A Schottky)

The "Green Dot 2040E5" Board is a Node that interfaces RS485 Sensor probes and can log information to the cloud using LoRa Connectivity. It uses the XIAO RP2040 and the LoRa-E5 (STM32WLE5JC) modules from Seeed Studio to do its magic. It also has amazing power management capabilities (Solar charging, Battery protection, etc) that make it very useful for IoT applications #internetOfThings #smartHomeDevices #SeeedStudio #XIAO #LoRa #RP2040 #IoT

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

ESP32-S3 CAM Audio-Visual Controller with I2S MEMS Microphone, Class-D Amplifier, SPI Display, Servos, Capacitive Touch and Integrated USB-C Power-Only Sink (VBUS via J6 -> 5V_IN -> SW1:P1 -> 5V_SW, CC1/CC2 5.1 kOhm to GND, VBUS TVS Surge Protection) + Added optional bulk electrolytic caps on 5V_SW near servo headers

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

Smart 12V Power / Charging / Protection Controller (Ideal Diode + PV MPPT + EXT CC/CV + OV/UV + Arduino)

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

Two-Bank 6 V Igniter Firing System with Onboard 2S LiFePO4 Pack, S-8252A Protection, BQ24618 LiFePO4 Charger (3 A, 3.6 V Fast, <50 mA Termination, 3.8 V HPPC, 3.5 V Float), 32 SOT-223 MOSFET Outputs via MCP23017, with Reserved PCB Areas for Dual 26650 Holders, 34-pin IDC, and Barrel Jack Input #LiFePO4 #Battery #BMS

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

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

9V Battery 1 Hz LED Blinker Using DIP-8 NE555 (THT) with SPST Switch and Reverse-Polarity Protection

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)

USB-C Digital Compass Module with STM32, HMC5883L, TM1637 Display, and Enhanced Power Protection (JLCPCB-Ready)