Enclosure

The Finished Build

The completed unit, with the PN532 reader/writer mounted near the top, the XIAO ESP32-C3 microcontroller tucked into the corner, and the U.FL antenna cable neatly wound around the built-in spool. The lid (right) snaps on with four screws.

3D Model

The model is provided as a 3MF file. It prints in two parts — the box and the lid — in PLA. Enable tree supports when slicing; the antenna-spool post has an overhang that needs them.

Download pn532-box.3mf

Salient Features

• Built-in antenna cable spool. The 50 cm U.FL antenna cable that comes in the 2-pack is far longer than the box is wide. Rather than letting it bunch up against the boards, the enclosure includes a central post that doubles as a spool — wind the excess cable around it and the inside of the box stays tidy.
• Top-cover support post. The lid has a short cylindrical post on its underside. When the lid is screwed down it presses gently on the XIAO ESP32-C3, holding the microcontroller firmly in its corner pocket. As a bonus, the same post sits directly over the U.FL connector and prevents the antenna pigtail from popping loose if the unit is bumped or dropped.
• PN532 mounting posts. Two standoffs on a diagonal align with the holes on the PN532 for mounting. The four standoffs in the corners of the box are for mounting the lid.

Assembly

1. Wire up the boards as shown on the DIY NFC page before putting anything in the enclosure — it is much easier to debug on the bench.
2. Drop the XIAO ESP32-C3 into its corner pocket, USB-C port facing the cable cutout.
3. Plug the U.FL antenna cable into the XIAO and wind the slack around the central spool post.
4. Seat the PN532 over the two diagonal standoffs and secure it with M2 screws (or a dab of hot glue if you prefer).
5. Set the lid in place — the support post should land squarely on top of the XIAO — and screw it down at the four corners.