Hardware is done! After months of prototyping, I finally finished the compact 40×15mm URU Key device—complete with ESP32, fingerprint scanner, security chip, LiPo battery, and USB-C. It’s basically a fitness tracker… but for secure authentication. Now onto the software (and maybe a proper case 😅).
Back to FPC1020 driver work! I fired up an ESP8266 with Arduino to detect finger presence using the scanner’s built-in sensor matrix. It’s simple, fast, and could help optimize image capture—or even act like a button or gesture detector. Full example code and visuals inside!
It’s official—URU Key is now a real, standalone device! I added the custom power board, used spring-loaded pins for easy firmware updates, and screwed everything together into a compact 35×20×10mm unit. Hardware’s basically done—now it’s time to dive deeper into the firmware, especially the biometric side.
Figured out how to measure battery level on the URU Key using a simple voltage divider and some clever GPIO control. Threw in some ESP32 ADC math to convert readings into a nice 0–100% percentage—and even blink a red LED if the battery’s running low. BLE support coming too!
Next step: power! I explored both CR2032 coin cells and tiny rechargeable LiPo batteries for the URU Auth device. Settled on a rechargeable setup with a TP4054 charger and USB-C—compact, convenient, and way more user-friendly. Bonus: added battery level monitoring and auto power-off to keep things efficient.
Everything’s finally coming together! I combined the ESP32, fingerprint scanner, and ATECC508A security chip into a single board—the first real version of my own FIDO2 Authenticator: URU Auth (You Are You). It’s handheld, it lights up, and it’s so close to being fully autonomous. Time to tackle power and fingerprint recognition!
Time to tackle the ATECC508A crypto chip! I started building an ESP32 component library to use it in my FIDO2 Authenticator. One chip gave me trouble, but another worked perfectly. Lots of I2C fun, ECC signatures, and some helpful inspiration from SparkFun’s Arduino library. One step closer to full hardware-based security.
Getting actual fingerprint data out of the FPC1020A scanner was way harder than I expected. After days of digging and reverse-engineering Android kernel drivers, I finally got it to scan! Now I can detect fingers and capture raw images—next stop: matching algorithms.