NXP Ntag i2c plus tag not getting detected via I2C

[indujanarayanan]

Hello,

   I am using NXP Ntag i2C plus tag. I am not able to communicate with the tag via I2C. However I am able to read and write via NFC.

Following were the different methods tried out

1)I checked with the NTAG I2C Explorer- Peek and Poke Utility. When scanned for the devices, it shows "I2C device not found"

2)I read all the settings like that of Configuration register , Session Register, the 0th block of NTAG etc via NFC and checked them against the working tag. All are same.

I tried changing the Slave address via I2C,from then this tag doesn't seem to work via I2C. I am not sure if changing the slave address killed the tag to write via I2C as Peek and Poke Utility scans for all the slave addresses.

Please help me out to resolve this issue as soon as possible.

Thank you

[IvanRuiz]

Hello,

First please check that the I2C protection is not enabled, you can do it in the NTAG I2C Demo app for android ->Config tab  -> Read/write config registers:

Please refer to Table 10.  Password and Access Configuration bytes for more information:

https://www.nxp.com/docs/en/data-sheet/NT3H2111_2211.pdf 

The byte 0 of block 0 is always read as 04h. Writing to this byte modifies the I2C address according to datasheet Table 7. NTAG I2C plus 2k memory organization from the I2C perspective.

I hope this helps!

Regards,

Ivan.