Simple NFC tag with embedded LED activated by 13.56MHz NFC or RFID readers.

This is a pause-to-embed model with no supports.
If using the STL files, manually add a pause for the LED and NFC embedding steps.

The 3MF files have pre-added pauses and a 2nd filament with the top and bottom painted.
Recommend printing the bottom circle and top logo in white or black for clarity.

I print this with the LED hole side down, requiring SA glue to keep the LED in place.
If you flip it 180-degrees, embedding the LED is easier with the adhesive side down.

The cylinder model is easier to hold onto and prints more reliably than the rounded one.

Link to embedded LED on Amazon ($1.04/unit - $7.29 total):
https://www.amazon.com/Nail-Stickers-Lighting-Adhesive-Intelligent/dp/B0BCQCH7Z4

Link to embedded NFC tag on Amazon ($0.22/unit - $11.18 total):
https://www.amazon.com/rewritable-Compatible-Enabled-Mobile-Devices/dp/B0932D8C3V

Around 8g of filament is used (accounting for waste) which is about $0.15.

So, the total cost for each tag came to $1.41 in materials.

Link to coin holder used in GIF:
Coin holder by Ej | Download free STL model | Printables.com