S(DES)

[eyals111]

Posted on February 09, 2014 at 09:26

hi , 

i having a problem with the deselect command , when i want to open and close Session on the I2C interface , the S(DES)  command doesnt close the session (by looking at the GPO) , only by turning ON/OFF the VCC   the session is closed.the deselcet  command that i am sending  via I2C is :C2 E0 B4    (PCB Byte + 2 CRC) according to chapter 5.4.1. am i missing something in the command ?2.the IC doesnt should response to the command  , only close the session (this should be visible by    looking at the GPO pin ) ? the procedure that i am doing on I2C is :1.open Session ,using GetSession Command  (O.K GPO is 0's , meaning Session is open)2.Select TAG command (O.K getting SW1 SW2 = 90 00 , Tag selected)3.Select file (NDEF File) (O.K getting SW1 SW2 = 90 00 , file  selected)3.Read/Update Command (O.K getting SW1 SW2 = 90 00  or extension frame delay )4.close Session , by Turn On/Off VCC (O.K GPO is 1's) , but i prefer using S(DES) #deselect #gpo #m24sr #m24sr

[Anais GALLIGANI · Accepted solution]

Posted on February 10, 2014 at 15:12

Hello,

If deselect is performed by RF it’s right there is no answer from M24SR.

But if command is sent by I2C the command is executed

only after

host has read M24SR deselect command response. I hope this is helping you, Best regards, ST NFC/RFID Dynamic tag support

[eyals111]

Posted on February 10, 2014 at 16:12

thanks for the quick reply , 

indeed what i was missing is reading the replay (I2C Interface) from the M24SR IC , after sending S(DES) Command . after that the Session was closed (the GPO goes to 1's) 

[Anais GALLIGANI]

Posted on February 11, 2014 at 15:35 Hello, Thanks, it will be specified in the next release of the Datasheet. Best regards, Have a nice day, ST NFC/RFID Dynamic tag