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)

Low-power consumer environmental sensor node powered from USB-C 5 V. Includes USB-C sink power entry with reverse polarity, OVP, UVLO, and OCP protection for 0.5 A to 3 A sources, 3.3 V regulation, an ultra-low-power Wi-Fi plus BLE MCU, and a digital temperature/humidity sensor connected over I2C. Intended as a schematic foundation for reliable PCB layout and manufacturing.

Multi-device wireless control system using a Seeed Studio XIAO ESP32-C3, 433 MHz ASK receiver, 5 V relay drivers, AMS1117-3.3 regulator, input protection, and PCB isolation between low-voltage control and relay output sections.

Hybrid EEG BCI for Pluto X v1.1 using ESP32-WROOM-32 and ADS1299-6PAG with LiPo charging, 5V boost, -5V analog rail, split 3.3V analog/digital regulators, six EEG channels, RC electrode protection, and 80x60mm mixed-signal PCB constraints.

Low-power USB-C 5V environmental sensor node with robust input protection, ESP32 Wi-Fi/BLE connectivity, digital temperature/humidity sensing, Bluetooth peripheral syncing, and EEG/PPG sensor interfaces for prototype biosignal acquisition.

Resonate Pendant golden reference design. Board is a 39 mm x 63 mm portrait rectangle with 5 mm corner radii, 2-layer FR4, 0.8 mm thickness, 1 oz copper on both layers, matte black top solder mask, no bottom solder mask, ENEPIG finish, and no silkscreen on either side. Allowed components only: U1 STM32L052C8T6, U2 CH340E, U3 BQ24210DQCT, C1 10uF, C2 4.7uF, C3-C7 100nF, R1 24k, R2 1k, R3 10k, D1 green 0402 LED, MAG1-MAG4 magnetic pads, J1 solar solder pads, J2 battery solder pads, TP1-TP4 test pads. Required top artwork: golden-ratio grid lines and gold circles on F.Cu with mask openings, decorative only, 0.8-1.0 mm width, at least 0.5 mm from active traces. Required bottom artwork: exposed ENEPIG bottom copper split into FREQ_OUT 61.8 percent and GND 38.2 percent with an exact 0.20 mm S-curve isolation gap, no vias through bottom except one PA4-to-FREQ_OUT via at the extreme edge. Functional requirements: MAG1 and J1 VIN feed U3 IN, U3 OUT feeds J2 battery pad and system VBAT, MAG2 to U2 UD+, MAG3 to U2 UD-, MAG4 to common ground, U2 TX to U1 PA10, U2 RX to U1 PA9, U1 PA4 to bottom FREQ_OUT, U1 PA5 to R2 then D1 to GND, U3 ISET to R1 to GND, U3 TS to R3 to GND, decoupling exactly as specified. Prohibited items: external crystal, JST connectors, wireless module, antenna, separate regulator IC, ESD protection IC, USB-C connector, through-hole parts, bottom solder mask, silkscreen, more than three ICs, or any unapproved substitutions.

Advanced health smartwatch platform with multimodal sensing, on-device AI, Wi-Fi plus cellular/eSIM connectivity, secure cloud sync, OTA firmware updates, and automatic emergency outreach over cellular/eSIM for fall and critical-event protection.

ESP32 Wearable Health & GPS Tracker with Biometric Security, TFT Display, and Enhanced Power & Data Protection

Portable Raspberry Pi Pico and NEO-6M GPS tracker powered by a single-cell Li-ion battery, with USB-C charging input, CC resistors, and USB-line ESD protection. Designed to support about 65 mA active current and roughly 30 hours from a 2000 mAh cell, following the performance targets from the evaluation paper.

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)