NFC-V (ISO/IEC 15693) tags

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I have a bunch of blank NFC tags from Texas Instruments (about 40 in total) in varying sizes (both physical and storage-wise), shapes, and casings. While I'm able to read them on my Galaxy S3, none of the apps I've tried are able to write to them.

After some poking around, I determined that these are all NFC-V tags (ISO/IEC 15693 compliant), which are apparently not NDEF-compatible. While the Android OS supports them, it provides no functionality to interface with them other than transcieve (raw read/write). Lacking the knowledge to write my own interface app, I'm reduced to research, questions, and experimentation.

Does anybody have any experience using Android to write to NFC-V tags? If so, what were you able to store and how did you do it?

https://play.google.com/store/apps/d...RhZ3dyaXRlciJd

try this app, it might work for you.

Thanks for the reply. That's actually the first app I tried, and no matter what type of data I try to write, I get the following: ow.ly/c5ubE

I've been putting a lot of my effort into getting this (ow.ly/c5uaz) app to work since it specifies NFC-V and ISO/IEC 15693 compatibility, but I still can't get it to write any data (NDEF or raw). From reading up on NFC-V, I get the impression this may be an issue with one-bit vs two-bit addressing and the app assuming which it is wrongly, but I have no way to confirm that. That said, the source for that app is available for download from its developer here (ow.ly/c5uaR) if anybody is interested in picking it apart.

Aren't they locked?
I can't give you more clues as I've just started reading about NFC.

Originally Posted by daniel_loft

Aren't they locked?
I can't give you more clues as I've just started reading about NFC.

Not that I'm aware. I can read them, and the access conditions allow writes. TI also advertises that they're shipped unlocked and unprotected.

Having done a fair amount of research since, it seems the issue is that NFC-V tags are not part of the NFC Forum standard, and there's no standard way to store NDEF data on them. Short of writing my own app with a proprietary method of doing so, I think the only option for those tags is to wait until NXP, TI, the NFC Forum, etc decide on a standard, then all the NFC Android apps update appropriately.

Fortunately, I've since gained access to the NXP Semiconductors samples ordering system, and their MiFARE tags are differently complicated but NDEF-formatable, so I'm making some headway.

Originally Posted by rowanator0

Not that I'm aware. I can read them, and the access conditions allow writes. TI also advertises that they're shipped unlocked and unprotected.

Having done a fair amount of research since, it seems the issue is that NFC-V tags are not part of the NFC Forum standard, and there's no standard way to store NDEF data on them. Short of writing my own app with a proprietary method of doing so, I think the only option for those tags is to wait until NXP, TI, the NFC Forum, etc decide on a standard, then all the NFC Android apps update appropriately.

Fortunately, I've since gained access to the NXP Semiconductors samples ordering system, and their MiFARE tags are differently complicated but NDEF-formatable, so I'm making some headway.

Hm, I belive that NFCIP-2 specifies something according to vicinity cards, but I don't remember what exactly. The main problem is though that the NFC chip of the SG3, which should be PN544 (not 100% sure, but I tihnk its the same as in the predecessor, and NXP didn't release PN547 yet) does not have the capability to write vicinity cards. I think there were datasheets on this though.

Originally Posted by Damastus

Hm, I belive that NFCIP-2 specifies something according to vicinity cards, but I don't remember what exactly. The main problem is though that the NFC chip of the SG3, which should be PN544 (not 100% sure, but I tihnk its the same as in the predecessor, and NXP didn't release PN547 yet) does not have the capability to write vicinity cards. I think there were datasheets on this though.

Can you define "vicinity" in this context? If you're referring specifically to NFC-V, you may be on to something. If you just mean proximity cards in general, though, I am able to write to MiFARE tags. Furthermore, as I understand it, with the right software behind an NFC reader/writer, you can theoretically read/write just about anything that uses 13.56MHz, simply as a result of the way the active field works.

Additionally, you seem to be correct about the NFC chip in the S3 (see ow.ly/foV15), but according to the NXP spec sheet for that chip (ow.ly/foUYj), it should be able to read/write tags that meet the same ISO standards as my TI tags. Apologies for the shortened URLs; I don't have enough posts yet to post links and that seems to be the only way to get around it.

Originally Posted by rowanator0

Can you define "vicinity" in this context? If you're referring specifically to NFC-V, you may be on to something. If you just mean proximity cards in general, though, I am able to write to MiFARE tags. Furthermore, as I understand it, with the right software behind an NFC reader/writer, you can theoretically read/write just about anything that uses 13.56MHz, simply as a result of the way the active field works.

Additionally, you seem to be correct about the NFC chip in the S3 (see ow.ly/foV15), but according to the NXP spec sheet for that chip (ow.ly/foUYj), it should be able to read/write tags that meet the same ISO standards as my TI tags. Apologies for the shortened URLs; I don't have enough posts yet to post links and that seems to be the only way to get around it.

ISO15693 is the vicinity card standard (basicly the same as the other ISO14443 standard, but those ISO15693 cards have a bigger range up to several meters). Cards that can be read via NFC-V are vicinity cards / tags. Though I checked again, you are right, coming from the data sheet, it should be able to read and write them.

Btw, your idea to be able to read and write anything that uses 13.56MHz is to idealistic. There are many kinds of cards and standards with many different protocols (many of them are even proprietary, like Mifare Classic, Legic, iClass etc.) involved in this. These protocols are most of the time implemented on the hardware level. One of the reasons for that is the fact that there are also very strict timings cards, tags and reader have to comply to. Going up layers of software can be to slow in that case.

You can read most of the ISO 14443 A and B compliant cards for example, but Mifare Classic can only be read with phones that feature chips that implement the ISO 14443-3 A protocol. The PN544 can read Mifare Classic, because hes manufactured by NXP, the same company that holds the patents and rights of the Mifare Classic standard.

Originally Posted by Damastus

ISO15693 is the vicinity card standard (basicly the same as the other ISO14443 standard, but those ISO15693 cards have a bigger range up to several meters). Cards that can be read via NFC-V are vicinity cards / tags. Though I checked again, you are right, coming from the data sheet, it should be able to read and write them.

Btw, your idea to be able to read and write anything that uses 13.56MHz is to idealistic. There are many kinds of cards and standards with many different protocols (many of them are even proprietary, like Mifare Classic, Legic, iClass etc.) involved in this. These protocols are most of the time implemented on the hardware level. One of the reasons for that is the fact that there are also very strict timings cards, tags and reader have to comply to. Going up layers of software can be to slow in that case.

You can read most of the ISO 14443 A and B compliant cards for example, but Mifare Classic can only be read with phones that feature chips that implement the ISO 14443-3 A protocol. The PN544 can read Mifare Classic, because hes manufactured by NXP, the same company that holds the patents and rights of the Mifare Classic standard.

Which leaves us pretty much back where we started.

As for my "WORKS WITH EVERYTHING" comment, you're absolutely right. I should have specified ISO14443/15693 (and even then my original statement would be wrong). Basically, I was referring to the fact that if you have the command set for something that operates on the 13.56MHz frequency, you can in theory write software to interface with it, as you can send and receive pretty much any raw data you want. However, you're right--there are plenty of 13.56MHz devices, both passive and active, that some active modules simply cannot communicate with.