1

I am working on a android application, need to read and display data from a type B card. card is connecting well,but when isodep.isConnected() is called it returns false.

I scanned this card with TagInfo application (by NXP, available on Play Store) it shows maximum Transceive length:0 byte for this card. Is there something wrong with this card ?

Alice
  • 71
  • 8

2 Answers2

1

The maximum transceive length refers to the capabilities of the NFC in the Android device. It seems the device cannot send data via IsoDep. What kind of device is it? Are you running a custom ROM?

NFC guy
  • 10,151
  • 3
  • 27
  • 58
  • I am using Samsung Galaxy S3 (4.0.4),NO its not on custom ROM. Also card we are using detected only by galaxy S3. have a look on issue for same card here: http://stackoverflow.com/questions/10831464/nfc-typeb-card-not-getting-detected-by-any-nfc-application-likenfctaginfo – Alice Aug 27 '12 at 06:15
  • The card we are using can be communicated using any contact-less smart-card reader,but smartphone are not able to connect(except S3) – Alice Aug 27 '12 at 06:19
  • 1
    I have experienced similar things with the S3. I have several Type B cards that have badly tuned antennas (tuned to around 20MHz). The S3 is still able to connect to them, but no other NFC phone I have tried can do it. BTW: the RF field emitted by NFC phones is much less powerful than that from any desktop card reader. – NFC guy Aug 27 '12 at 13:22
  • Thanks, We also performed some test with Nexus S using external antenna and then were able to detect typeB cards. – Alice Aug 28 '12 at 06:26
  • Were you able to send APDU (Send and receive data ) to such typeB card using S3 ? If so, how it was possible. Please help me. – Alice Aug 31 '12 at 05:16
  • 1
    FYI: TypeA is more or less the NXP house technology. All their tags are based on it, from Ultralight via Mifare to Desfire. TypeB ototh is the house technology of NXPs direct competitor. Since they have a de-facto monopol on NFC chips at the moment they seem not to care about TypeB. I conducted some tests using the S3 today, and (with tweaked antenna) I was able to connect to the tag. The PN65 chip with the firmware version present in my phone crashed on pdu exchange though. Go figure! TypeB with NXP chip seems not to work at the moment at all. – Nils Pipenbrinck Aug 31 '12 at 19:11
0

The Tag INfo app may derive the Maximum Transceive Length from the MBLI attribute.
MBLI = Max. Buffer Length Index. It is the upper nibble of the first byte of ATTRIB Response. Some Type B tags have 0 in this nibble which means 'No information provided'.

For some indication of what you're looking for, you could use the 'Max Frame Size', given by the 'Protocol Info' section of the tag's ATQB response. See page 19 of this reference. Your options (in bytes) are 16,24,32,40,48,64,96,128,256

Papyrus
  • 232
  • 3
  • 10