Investigate EV3 Support

[johnnyb]

Just received a package of EV3 tags. They don't work with the example app out of the box, so using this ticket to record what I'm seeing/messing with.

[johnnyb]

Tag Tech reports: android.nfc.tech.IsoDep, android.nfc.tech.NfcA, android.nfc.tech.NdefFormatable

Here is the initial communication:

BytesSending: 00A4000C02E11000
BytesReceived: 6A82
BytesSending: 90640000010000
BytesReceived: 009100
BytesSending: 9071000002000000
BytesReceived: 91AE
BytesSending: 9071000002000000
BytesReceived: 91AE

[johnnyb]

Here is a document describing some EV3 communication:

https://medium.com/@androidcrypto/mifare-desfire-ev3-a-beginner-tutorial-android-java-using-the-desfire-for-android-tools-00aaecb8fa93

[johnnyb]

Created branch ev3-support (nothing in it yet).

[MichaelsPlayground]

As a starting point you should select the tag by this command sequence:

00 a4 04 00 07 d2 76 00 00 85 01 00

Thats the "byte SELECT_MODE_BY_FILE_IDENTIFIER = 0x00" method using the default DESFire identification "d2 76 00 00 85 01".

This is similar to the command "IsoSelectFile.run(communicator, IsoSelectFile.SELECT_MODE_BY_FILE_IDENTIFIER, Constants.DF_FILE_ID);" but using "d2 76 00 00 85 01" instead of "byte[] DF_NAME = new byte[]{(byte)0xd2, 0x76, 0x00, 0x00, (byte)0x85, 0x01, 0x01};" for the NTAG 424 DNA tag.

The next step could be a "list applications" command (that would give no data as no application is available on a fabric tag (the NTAG 424 DNA tag has an application pre-installed). The following commands would be to create an application and create a (Standard) file. From this point you could use the read and write commands available in the library (after a "select application" and an authentication, depending on the file settings).

I'm glad that you are trying to expand the library to DESFire (EV3) tags as well !

Greetings
Michael

[johnnyb]

Many thanks! I'll give this a try soon hopefully.