4-axis ESP32 DevKit v1 to DM542T stepper driver level shifter board using two SN74AHCT125N DIP buffer ICs, 5V screw-terminal power input, driver signal terminals, and 100 mm x 60 mm PCB.

Controller-less 16×16 WS2812B RGB LED matrix panel with external 5 V high-current screw-terminal power input, JST data in/out connectors, fuse protection, bulk capacitance, and power injection points.

5 V Omron G2RL relay driver PCB using an MMBT2222A low-side transistor, input terminals, flyback diode, and screw-terminal relay output.

Jerky Robot V3 100 mm × 152 mm 2-layer control board with ESP32-S3 and Arduino Nano sockets, screw-terminal I/O, BSS138 UART level shifting, PC817 sensor isolation, optional HX711 interface, status LEDs, test points, top-side component placement, and bottom GND fill for JLCPCB fabrication.

Reusable ESP32-WROOM golf ball dispenser interface board with protected 12V to 24V input power, one conditioned coin pulse input, SPDT relay dry-contact output, open-collector output, Bluetooth pulse generation, screw-terminal field wiring, and optional UART programming access.

ATmega328P 5V External-Powered Clock and Reset Core (16 MHz Crystal, Screw-Terminal Input)