Modding payWave into my Casio F-91W

Having gotten use to contactless payments from my Apple Watch, I wanted to mod my Casio to do the same.

My bank offers PayTag (from Gemalto), shrunken down versions of a normal credit card, but without the magstripe or chip, just the contactless coil. They were launched before Apple Pay and Google Pay arrived in New Zealand, a poor man’s mobile payment alternative.

I submerged the sticker in acetone for about half an hour. After the plastic dissolved, I peeled and cleaned off the remaining plastic parts leaving only the NFC coil and IC exposed. With a bit of care, I rewound the coil to fit inside the body of the watch, glued it down, and repacked it all together.

And here’s a demo of me ordering some wicked wings with it.