Arduino Nano DCC PCB Design

Need a compact, single-board solution that seats an Arduino Nano and handles full DCC interfacing for model-rail accessory control. The board’s sole purpose is to speak DCC, pass the signal cleanly to the Nano, and drive external accessory decoders (LEDs)— no motor or sound functions, just reliable accessory switching.

Core requirements
• DCC input stage with proper isolation or differential reception so the Nano sees a clean, 5 V logic signal.
• On-board 5 V regulation from track power (typically 14-18 V AC/DC).
• Screw-terminal outputs sized for accessory decoder lines (LEDs, relays, servos, etc.) - one for each pin from Nano
• Clear silkscreen legends for field wiring.
• Mounting hole in each corner.
• A switch must be able to switch between DCC input between pin 2 and pin 3 on the Arduino.

Deliverables
1. Schematic and PCB layout files (KiCad preferred, Eagle acceptable).
2. Complete BOM with manufacturer part numbers.
3. Gerber, drill, and pick-and-place files ready for fabrication.
4. Brief design note explaining component choices and expected current limits.

Design can reuse proven DCC receiver circuits if licensing permits; otherwise a fresh implementation is fine. All work must be original or open-source-compliant. I’ll confirm the design by ordering boards and loading my own firmware, so pin naming must match standard Arduino Nano pinout.

Turnaround: first review of schematic within one week, final files a few days after feedback is incorporated.