Carrier PCB schematic for a four-wheel Arduino Nano ESP32 spy car using two TB6612FNG motor-driver modules, removable Nano sockets, servo/sensor/light/buzzer connectors, and protected shared battery power. PCB layout is intentionally deferred pending module dimensions and electrical ratings.

Arduino Nano-based DCS-BIOS RS-485 interface module using a MAX487CPA+ transceiver and two RJ45 sockets for bus daisy-chaining.

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.