Simple script I've made for the "Hackaday Europe 2026 Badge Hacking Ceremony".

Allows to connect a PN532 to the SAO connector and read the UID of tags that operate in the 13.56MHz frequency, then prints the reading on the screen of the badge.

(During the ceremony I used a bad combination of font color and size, so it was difficult to see it on camera, this version is using black background and big white font)

Just set the PN532 to work in I2C mode using the dip-switch available and connect it to the SAO pins, respecting the order:

Upload the dependencies and the app

mpremote cp adafruit_pn532.py :libs
mpremote cp pn532_i2c.py :libs
mpremote cp saonfc.py :apps
mpremote reset

The "Home" button seems to be unresponsive, but it's being blocked by the timer thatkeeps the UID on screen. You can turn it off and on again or press that button really fast and it will exit the app.