You know that "X billion devices run Java" claim, with the number that keeps going up?

Well, since the install described in Integrity and Progress, I'm one of them. This Java card implant has an impressive amount of functionality. I use it almost daily (I'm in the process of writing a post describing everything I use it for). I interact with it using an NFC reader—either a smartphone (more on that coming too), or a USB device plugged into a laptop/desktop.

You can see I have this awkward block holding the reader in place at a comfortable angle. It moves around a lot otherwise, and is altogether somewhat unwieldy and inconvenient to lug around. At present I have enough redundancy so that none of my usual use computing needs would be made impossible by not having the reader, but that may change as I continue to lean into this.

I decided to install an NFC reader into the laptop itself.

So this laptop, a ThinkPad X230 (Librebooted, of course), has a plastic palmrest and a PC card slot that has never been used before. I thought that slot cleaned up a bit might have just enough real estate to hold a reader I already have (an ACR122U, which I have already replaced with an ACR1252U in daily use). I know there's also a spare mini PCIe slot in the mahine too, which I figured would be able to get me connected one way or another.

So I tracked down some parts, and got to work.

All I used was:

• An ACR122U (EoL; can be found secondhand)
• A Mini PCIe to USB adapter
• A ferrite sheet

...and some basic tools; a soldering kit, a bit of electrical tape.

The reader and adapter, before hacking away at them:

I stripped the case off the reader

The USB head is a lil' clunky... poor guy :(

Ditched this thing. Have literally never used it.

This is about where it will end up

Stripped some bulk; much better

I shaved away a piece of this metal frame, but ended up not needing to.

However, the casing on the speakers is a bit large; I took a chunk out of the plastic—it miiight impact acoustics, but the speakers are garbage anyway...

Rough positioning... I actually ended up flipping it over from here.

So it reads! But there's an issue... it disconnected whenever I put it all together!

It seems to be getting some sort of interference from the rest of the computer. That won't do....

A friend suggested a ferrite sheet to shield it.

I didn't get a pic of it placed, but I just slapped one of these bad boys on the board, right under where the coil is on the reader.

...and it all came together!

Limitations:

• There's no switch to turn it off. In testing, the reader pluggin in emitted a high-pitched whine. I was advised to try putting some resistors in line, but once everything was assembled, it stopped doing it (except sometimes when asleep). If it becomes a problem, I'll consider revising.
• The fit's a liiiitle tight. The corner of the palmrest bulges slightly. Incidentally, this laptop had the corner chipped and one of the clips compromised; I'm unsure whether it would work on an intact machine.

All in all, a little hacky—but that's what we do here, isn't it? ;) I'm quite pleased with it; I bought some spares to mess with similar configurations on some other hardware I use... I may do another writeup if I end up with something like this anywhere else.