Problem with st25dv16k ISO 15693 iOS communication

[koy]

Hello!

I am trying to read some blocks from a iso 15693 tag. I can do it with Android without any problem. But when I try to do it with iOS I always receive the response [255,255]. What does it mean?

For example:

22 33 E0 02 51 00 02 4E BE 55 08 00 32 00 

Flags: 22

Function: 33 (Extended read multiple blocks)

Uid: E0 02 51 00 02 4E BE 55

Start block: 00 08

Number of blocks: 00 32

I don't know if the problem is the CRC16.

It occurs the same when I try to send the present password (B3 function), I receive the same response.

I know is not necessary to append it in Android, but, is it necessary in iOS?

which algorithm of CRC16 I have to use?

which bytes I have to use to generate CRC? all the message (22 33 E0 02 51 00 02 4E BE 55 08 00 32 00)? 

Thank you!

[Brian TIDAL]

Hi,

The UID is transmitted least significant byte first. In your trace "22 33 E0 02 51 00 02 4E BE 55 08 00 32 00 " the UID is most significant byte first.

Rgds

BT

[koy]

Hi!

I tried:
22 33 55 BE 4E 02 00 51 02 E0 08 00 32 00

22 33 55 BE 4E 02 00 51 02 E0 08 00 32 00 0E 7F

22 33 55 BE 4E 02 00 51 02 E0 08 00 32 00 7F E0

And the same code appears [255,255]. ¿what does that code mean?

thank you in advance

[Ulysses HERNIOSUS · Accepted solution]

Hi,

rather than diving straight into more elaborate commands I would start off with a standard read single block.

I would be surprised if the CRC would be needed by iOS. I think you you should be able to inspect STSW-ST25IOS002 which should show you how to use iOS for your use cases.

BR, Ulysses

[koy]

Great! I did it and I can read all the memory. Now I will try to read multiple blocks.

Thank you!