topic Re: Problems doing updateBinary in NFC

Problems doing updateBinary

larryansell — Tue, 13 Nov 2018 00:10:41 GMT

Problem doing updateBinary on ST25TA 8K. I have been able to write using updateBinary only several times. Most often I get a strange set of bytes.

For example:

I send 16 bytes using the NDEF updateBinary command after the NDEF Select file

0x2 0x0 0xd6 0x0 0x4 0x10 0x54, 0x77 0x61 0x73 0x62 0x72 0x69 0x6c 0x6c 0x69, 0x67 0x61 0x6e 0x64 0x74 0x68

and I get back

0xf2,0x2,

Which almost fits as a WTX but the bits 7 and 6 are not set. So it's almost like a deselect?

Sometimes I get no response from the card.

Any insight into this would be greatly appreciated.

Thanks,

Larry

Re: Problems doing updateBinary

stephanie_m — Thu, 15 Nov 2018 20:59:27 GMT

Hello,

Could you please let me know which reader or frontend are you using?

Regards,
Estepahania

Re: Problems doing updateBinary

larryansell — Thu, 15 Nov 2018 21:12:58 GMT

Hi Estepahania,

I’m using a pn5180, with code modelled on the nxp reader lib.

Thanks,

Larry

Re: Problems doing updateBinary

harrybellen11 — Sat, 17 Nov 2018 10:25:26 GMT

Can you please explain it a bit? I mean what's exactly you are facing and all such stuffs, so that I can guide you. Thanks and Regards, Harry Bellen.

Re: Problems doing updateBinary

larryansell — Tue, 20 Nov 2018 20:52:35 GMT

Hi Harry,

Thanks for your email!

It was explained to me that the f2 2 was in truth a WTX. I had been looking at the ST25TA64k doc(where the table was labelled S-Block detailed format), but in the corresponding table in the ST25TA2k doc, the table is labelled PCB field of the S-Block format) so that makes sense.

Now (with a different card) I am writing an 8 byte message successfully at offset 4 but when I try a longer 16 byte message I get no ACK/NAK. I’m suspicious that I need to zero the NDEF but when I tried overwriting the two bytes at offset 0, I once again got the no ACK/NAK. But when I changed my offset back to 4 (where I had been writing the 8 bytes successfully) I was once again able to write the 8 bytes.

I would be grateful for any guidance!

Thanks again,

Larry