RE: NFC Tag Type for rwpayload and staticpayload at same time.

Arepa — Mon, 24 Apr 2017 22:06:31 GMT

Hi michaeld, what libaries are you using? I am trying to do the same task, but I am a little missing about the uuid_msg_encode and name_msg_encode you are using. where are it defined? Thanks

RE: NFC Tag Type for rwpayload and staticpayload at same time.

michaeld — Fri, 24 Mar 2017 14:38:55 GMT

Thanks! I will check out these things and report back.

RE: NFC Tag Type for rwpayload and staticpayload at same time.

Michal — Fri, 24 Mar 2017 14:04:56 GMT

Hi, according to the Type 4 Tag specification, I think it should be possible to have multiple NDEF files in a tag. However the Type 4 Tag library in the nRF5 SDK supports just a single NDEF file as part of the T4 Tag.

The code above basically overwrites the read/write content by static content (non-writable).

So to have both a read-only and R/W content at the same time, you will have 2 options:

keep an NDEF data backup for the non-writable data, and once the non-writable section is updated by the Reader/Writer, the application can revert this data using the mentioned backup. In this solution keep in mind, that the reader will think the update was successful (it will get back status word "success"). Also remember to keep the NLEN (NDEF length) field compatible when reverting updates.
use nfc_t4t_lib in raw mode, running pure ISO-DEP commands (as described in the SDK documentation: T4T doc) and implement multiple NDEF file emulation on application level. Then the separate NDEF files can have different access rights.

Regards, Michał