Java Question Adding new functionalities and tags decoding to NFC library

jjcc said:

The attachments are the new version of NFC library and a sample application. I added some extra java code to the library by Sherlok and Erel.

Here's how to use the lib:
1.initialize a "MiFare" object.
2.Call ReadSector() method with 3 parameters: SectorIndex, KeyData, KeyType
3.If succeeded, retrieve the data block by block with method GetBlockData()

B4X:

Sub Read()
   Dim key(16) As Byte 
   Dim block_data() As Byte
   Dim bc As ByteConverter



   
   Dim i As Int
   For i  = 0 To 15
      key(i) = 255 '0xff
   Next

   'btnClear
   Dim mfc As MiFare
   Log("Check if the card is MF classic")
    If NFC.IsMifareClassic(Activity.GetStartingIntent) Then
      Dim StrData As String
      mfc.Initialize(Activity.GetStartingIntent)
      If True = mfc.ReadSector(0,key,0) Then' Read sector 0, key, type 0(as keyA)      
         Log("Read sector done")
         For i = 0 To 2 'read 3 blocks of data
            block_data = mfc.GetBlockData(i)
            StrData =  bc.HexFromBytes(block_data)
            Log( "data:" & StrData)
            If i = 0 Then
               Label1.Text = StrData
            Else If i = 1 Then
               Label2.Text = StrData
            Else If i = 2 Then
               Label3.Text = StrData
            End If
         Next
      End If
   End If
End Sub

In manifest editor, I added "android.nfc.action.NDEF_DISCOVERED" and "android.nfc.action.TAG_DISCOVERED" intent filter. Actually "android.nfc.action.TECH_DISCOVERED" is better than NDEF_DISCOVERED but it needs some code like:

B4X:

  <meta-data android:name="android.nfc.action.TECH_DISCOVERED"
          android:resource="@xml/filter_nfc" />

I don't know how to put the "filter_nfc.xml" under "res/xml" directory. Maybe Erel knows.

Good luck

Click to expand...

Rafal Galewski said:

When I try open sample project I have error missing 2 files:
-Main.bal
-UriView.bal

If You could please shere it.

Thank You :sign0098:

Click to expand...

Erel said:

Please do not post duplicate questions.

Click to expand...

walterf25 said:

Hello, i've tried this library and it seems like there's something missing, I copied both files .xml and .jar to my additional libraries folder, but when I open the example and try to run it i get an error, it seems as there's still missing a file.

the problem is at this line

B4X:

Dim mfc As MiFare

that line remains in color red, which means that there's no library associated with MiFare, what am I missing?

thanks,
Walter

Click to expand...

jjcc said:

I've updated the code. Meanwhile, fixed a couple of bugs in Lib.
Attached Files:
NFC2.22.zip
File size: 8.9 KB

Click to expand...

raphaelcno said:

The ZIP file is called NFC2.22, but the version in the XML file is 1.22.

Click to expand...

raphaelcno said:

The ZIP file is called NFC2.22, but the version in the XML file is 1.22.

Click to expand...

StevieDk said:

Hello,
NFC lib works wonderfull, thanks all for your work. I will need to write on a MIFARE tag, as far as i know, that feature is not implemented yet.
I will like to help on it, so we can all have the utility. I am farely new on this blog, so i am not use on where / how to access java code of the lib so i can continue ( or try to) your excellent work.
Thanks

Steve

Click to expand...