• ssd
  • New member
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  • Registered: 2009-08-19
  • Posts: 1

Topic: Pn531 I2C interface problem

Hi,
We have interfaced PN531 NFC IC to the one of the host controller.
I am successful in HSU mode, able to send the command  and receive the response from/to the
PN531 now I am tring for I2C interface, I am getting the acknowledgement but receving some wronge response.
e.g.
Command:
GetFirwareVersion[9] = {0x00,0x00,0xFF,0x02,0xFE,0xD4,0x02,0x2A,0x00}
Response:
00 00 FF 00 FF 00 00 00 FF 02 FE D5 04 02 27 00

Can anyone guide for this.

Thank you.

  • roel
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  • Registered: 2009-02-18
  • Posts: 151

Re: Pn531 I2C interface problem

There seems to be nothing wrong with your board.
The message you receive contains the answer:

00 00 FF 02 FE D5 ==> 04 02 <== 27 00

Contains the version number: 4.2
After D5 it start with response bytes.

Check out this forum post for more information about the communication.
http://www.proxmark.org/forum/post/651/#p651

  • Registered: 2009-09-24
  • Posts: 6

Re: Pn531 I2C interface problem

Hi ssd,
how did you do with pn531 to interface with host controller via i2c interface ? can you give me some guidances or some piece of your code ?
I am going to interface pn532 with host controller via i2c interface on linux platform ...
Any body else had experiences on this ? Pls give me some clue ... thanks very much

  • rconty
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  • Registered: 2009-04-22
  • Posts: 642

Re: Pn531 I2C interface problem

tungsys wrote:

Any body else had experiences on this ? Pls give me some clue ...

You may be interesting in
* http://i2c.wiki.kernel.org/index.php/Main_Page
As libnfc run in userland, you should use i2c-dev interface:
* http://git.kernel.org/?p=linux/kernel/g … -interface
Some userland I2C tools written in C could help to understand how it works:
* http://www.lm-sensors.org/browser/i2c-t … 2cdetect.c

Hope it helps.

Romuald Conty