A PCB business card with a batteryless LED, powered by the phone that taps it
Summary
A hardware-focused diary about building a batteryless, NFC-powered LED business card. The author designs a credit-card sized PCB with an NTAG I²C Plus chip and a Charizard LED that lights when tapped by a phone, all powered by energy harvested from the NFC field. After initial write hurdles due to the chip requiring low-level commands, a tiny Core NFC app writes the URL directly to the chip; the project highlights the edge where hardware meets software and showcases programmable, reproducible hardware via KiCad.