Industrial Raspberry Pi CM4/CM5-compatible RTK base-station carrier with PoE+, external DC input, BQ25750 2S Li-ion UPS, USB hub, Mosaic-X5 mPCIe GNSS, Quectel EM05 LTE, Ethernet, watchdog, protection, and JLCPCB-focused manufacturing constraints.

Raspberry Pi 5 HAT with 12V DC input protection, 12V-to-5V buck regulation, 40-pin GPIO header, MPU6050 I2C header, NEO-8M UART header, and GPIO status LED.

Four-phase 0.5–100 V, 0–40 A programmable CV/CC bench supply architecture. High-power AC/DC modules and contactors are modeled as off-board interfaces; the PCB schematic focuses on buck power stages, control, sensing, protection, and auxiliary rails.

Production-intent USB-C macropad based on ATmega32U4 TQFP-44 with 11 Cherry-MX hotswap keys, EC11 encoder, per-key diodes, USB ESD protection, and deferred routing until case STEP alignment.

KiCad schematic reconstruction for YachtWave Rev B: ESP32-S3 controller with power input, USB-C, SD card, CAN bus interface, indicators, and protection circuitry.

12V analog temperature-controlled TEC phone cooler: NTC sensor switches a TEC and fan at about 40°C using a comparator, with DC input protection and no MCU/firmware.

12V analog temperature-controlled TEC phone cooler: NTC sensor switches a TEC and fan at about 40°C using a comparator, with DC input protection and no MCU/firmware.

Production-intent ESP32-C6 controller for WS2812B/WS2815 addressable LED strips with 5V/10A input protection, strip high-side switching, 5V data level shifting, user buttons, and antenna keepout requirements.

Isolated 220 VAC to 5 V / 2 A power supply using a certified AC-DC module, with potentiometer-controlled PWM output for a 5 V load. Includes mains input protection and safety documentation assumptions.

USB-C 2.0 power entry with ESD protection and automatic USB/battery ORing onto a shared 5 V system rail.

Power-section schematic for a 12V DC input generating +4V for a 4G module, +5V, and +3V3 rails with input TVS protection and regulator thermal notes.

Power-section schematic for a 12V DC input generating +4V for a 4G module, +5V, and +3V3 rails with input TVS protection and regulator thermal notes.

Compact rechargeable BLE controller board with a 4x8 RGB LED display, USB-C LiPo charging, battery protection assumptions, and firmware-controlled LED current limiting.

Power-section schematic for a 12V DC input generating +4V for a 4G module, +5V, and +3V3 rails with input TVS protection and regulator thermal notes.

Universal PWM Interface Module: 12 V automotive-input board for configurable ECU PWM input conditioning and open-collector fan-module output, with TVS/reverse-polarity/PTC protection, 5 V buck, 3.3 V LDO, selectable pull-up rails, inversion jumper, status LEDs, test pads, mounting holes, and DT13-08PA connector placeholder.

Arduino Uno R4 WiFi shield/carrier PCB for the C4 Coffee Co smart scale prototype, integrating RS485 load-cell wiring, service connectors, display/buttons, protection footprints, and test access.

Industrial ESP32-S3 master gateway with Ethernet (W5500), LoRa 433 MHz, microSD storage, RTC, USB-UART console/debug interface (CP2102N), and isolated RS485 ports using ADM2587 transceivers. The design includes ESP32-S3-WROOM-1-N16R2 as the main controller, W5500 Ethernet, LoRa antenna interface, microSD connector, RTC circuitry, CP2102N USB-to-UART programming/debug console, SC16IS752 UART expanders, isolated RS485 channels, power regulation, ESD/surge protection, connectors, and mounting holes. Cellular/BG95/SIM functionality and true RS232 console hardware are not included; J1 is used only as the microSD card connector.

Regenerative braking power generation and charging circuit using two DC motor generators, rectification, TVS protection, supercapacitor buffering, a 2S Li-ion buck-boost charger, BMS protection, and regulated 5 V/3.3 V load rails.

Safe low-voltage educational residual-current device demonstrator for wet-area protection concepts

USB-C TKL Hall-effect keyboard with hot-swap switches, rotary encoder, ESD protection, and app-configurable firmware architecture.

Arduino Mega 2560 sensor/actuator interface shield for a firefighting differential robot with labeled connectors, onboard IR receiver, buzzer, MPU6050 header, battery VIN protection, battery sensing, LED outputs, and fan MOSFET control.

USB4 external NVMe SSD enclosure PCB targeting an ASM2464PDX-class USB4 40 Gbps device controller with PCIe Gen4 x4 downstream M.2 NVMe interface, USB-C upstream port, power management, ESD protection, and controlled-impedance layout constraints.

Multi-subsystem ESP32-S3 coffee maker/alarm controller board for a Coffee Waker appliance. The design uses an ESP32-S3-WROOM-1-N8R8 module as the main Wi-Fi/Bluetooth MCU, with USB-C 2.0 device connectivity through a USB4105-GF-A connector, 5.1 kΩ CC pull-downs, and USBLC6-2SC6 ESD protection on the USB D+/D− pair. Power architecture includes a 12 V input on a JST VH B4P connector, a TPS62932 buck regulator generating the 5 V rail, a TLV1117LV33 3.3 V LDO for MCU/logic power, and TPS22919 load switches for controlled 3.3 V/5 V peripheral rails. Functional blocks include an NAU7802 load-cell ADC on I2C with two differential load-cell channels, a MAX98357A I2S audio amplifier/DAC with speaker/output filtering, a microSD socket on SDIO, I2C/test headers, UART/programming header, and auxiliary JST VH connectors for wake-light or external loads. The high-voltage section includes 120 VAC input/output screw terminals, a 5 V SPST-NO relay rated 15 A / 240 VAC max, a 1 A fuse, MOV surge suppression, diode snubber, and a dedicated heater output terminal.

10-channel relay board for externally protected AC live switching with 24V coil drive harness, per-channel fuses, direct neutral/PE distribution, and local relay flyback protection.

Industrial 24 V DC MESBox controller with embedded Linux SOM, STM32 real-time I/O, triple RJ45 Ethernet, TFT display, isolated inputs, protected transistor outputs, offline memory, surge/reverse-polarity protection, and EMC-focused layout constraints.