A compact DIY FIDO2 security key can be built around Nordic Semiconductor’s nRF52840, which provides the processing, native USB connectivity, and hardware-accelerated cryptography needed for secure authentication.

In this project, we built a DIY inline USB-C power meter that measures voltage from 5 to 28 V and current up to 5 A. It also tracks charge and energy consumption, records minimum, maximum, and average readings, and displays a rolling 30-second graph of voltage, current, and power on a colour IPS display.