LWN: Comments on "NFC programming on desktop Linux"

Re: NFC programming on desktop Linux

hadess — Tue, 30 Jun 2015 13:41:40 +0000

I'm all for enhancing hardware support in the desktop, I even have one of the early "Tikitag" RFID kits, and there might be an NFC reader in the cheap Chinese tablet I got some time ago. Unfortunately, despite me turning this every which way, I can't find good use cases for desktop integration, or things that wouldn't require very specific knowledge of the tags read.

For example, I'd love to be able to tap my bike rental card, and see the last few trips I made through its website, or tap my credit card and be brought to my bank's login page. But I couldn't find generic ways to do this. But if you do, feel free to come talk to me about it :)

NFC programming on desktop Linux

gerdesj — Sun, 31 May 2015 23:28:08 +0000

"In that case you might be interested in BlueProximity which is packaged at least in Debian and derivatives."

Thanks for the heads up. As it turns out Gentoo is pretty multi-lingual and I'm sure it speaks Debian - I know it can deal with RedHat (but with a pretty bad accent)

Cheers
Jon

NFC programming on desktop Linux

dash — Sun, 31 May 2015 22:18:40 +0000

In that case you might be interested in BlueProximity which is packaged at least in Debian and derivatives.

NFC programming on desktop Linux

gerdesj — Sat, 30 May 2015 22:59:50 +0000

"NFC has a very, very short range of about 4 cm; in practice you usually need to touch the back of smartphone to NFC tag"

Thanks for the response. This occurred to me shortly after I "paid by bonk" for a coffee today and had to contort myself to actually get at the bloody reader that was positioned badly by the till and other stuff on the counter.

NFC is clearly not what I'm looking for here unless I want to be seen playing pocket billiards whilst attempting to get my mobe and laptop in the right position. The left hand side USB ports are towards the rear (as I see it) of my laptop, near my knees, which is the side I usually have my mobile. Now the RHS ones are at the front - right next to my pocket.

Bluetooth it is then.

NFC programming on desktop Linux

jnareb — Sat, 30 May 2015 09:16:23 +0000

NFC has a very, very short range of about 4 cm; in practice you usually need to touch the back of smartphone to NFC tag (this is at least the case of MasterCard PayPass). This is similar to how you unlock the door with the smart card, or pay for bus or subway - you need to almost touch the reader.

For "neighbourhood" (around 0.5 meter - 1 meter) unlocking you would need Bluetooth, I think.

NFC programming on desktop Linux

gerdesj — Fri, 29 May 2015 23:05:54 +0000

Thanks for doing some research on this - it will save me a fair amount of time.

I had this idea that as I generally keep my mobile (cellphone) in my pocket then my laptop could unlock when it senses it and lock when I move away. I could override this with a password or a token or something if the laptop is on a desk and/or my mobile is in the car/toilet.

I was about to make a silly quip about waiting for pam_nfc to appear and then did a quick Google - http://nfc-tools.org/index.php?title=Pam_nfc . I even guessed the name correctly.

Play time!

NDEF format

jnareb — Fri, 29 May 2015 18:09:15 +0000

Isn't the NDEF (NFC Data Exchange Format) the standard of writing generic messages to NFC, a common data format?

That specialized NFC devices (MiFare, PayPass ATM cards,...) do not speak it is another matter...

NFC programming on desktop Linux

foom — Fri, 29 May 2015 15:25:19 +0000

Unfortunately, the tag you chose to highlight here, MiFare Classic, speaks a nonstandard proprietary protocol, and only works with readers made by NXP. Which excludes many popular mobile phones.

NTAG203 or NTAG213 are a better option for standard tags.