Let's Build a Card Cloner

This post provides complete, actionable instructions to build a long-range 125 kHz proximity card cloner and an embeddable variant, including BOMs, PCB/drill templates, hardware modification steps, and Arduino code for logging card IDs to microSD. The guide enables covert capture and cloning of access credentials from LF proximity cards, posing a material risk to physical access security for systems relying on these cards.