RE: Confusion on TLV, CC, and general Type 4 tag functionality.

Petter Myhre — Wed, 14 Dec 2016 11:15:52 GMT

If Michał answered your question please accept his answer by clicking the grey circle next to it. Thanks.

RE: Confusion on TLV, CC, and general Type 4 tag functionality.

CurtisHx — Tue, 13 Dec 2016 15:06:23 GMT

Gotchya. So I was trying to use the Type 4 Tag reader library to parse the data written to the nRF52. Makes a bit more sense now.

RE: Confusion on TLV, CC, and general Type 4 tag functionality.

Michal — Tue, 13 Dec 2016 15:00:10 GMT

Let me try to clarify this documentation a little bit.

The documentation at Type 4 Tag NDEF detection procedure is only related to reading Type 4 Tags, and is not needed for implementing a tag (so not needed for the Type 4 Tag sample application). This section describes software modules which are required to parse T4 Tags. These modules are only used in the "adafruit_tag_reader" example which requires additional hardware (Adafruit PN532 shield - a NFC Poller device). This reader example can be used to test the T2 and T4 Tag sample applications in an embedded environment (instead of using phones or tablets).

However, when running just the Tag sample application (no external HW required), no detailed knowledge of Type 4 Tag memory structure is required. Memory mapping, Capability Container settings, APDU's encoding/decoding and required TLV's are handled internally by the "nfc_t4t_lib" library.

As a side note I can add that, it is possible to run Tag emulation (Type 2 or Type 4) together with a NFC reader at the same time, because the NFC Tag HW is integrated in the SoC and the Reader uses external NFC Hardware which communicates with host using TWI. However no such example is available in the SDK at the moment.

Finally, it might happen that for some users, some parts of the SDK documentation may be not very well structured or somewhat misleading. That's why we greatly appreciate such feedback, and try to use it to improve, and make the documentation more understandable.