How to write only one byte in memory of ST25DV04K using the CR95HF Development Software?

[JOliv]

Hello!

I am starting my activities with the Demonstration Board MB1054A CR95HF and according to what I understand it is only possible to write in a block of 4 bytes, I wonder if there is how to write in only 1 byte?

Detail: mine NFC tag is ST25DV04K.

Regards,

João Pedro, Engineering Student from Brazil.

[Brian TIDAL · Accepted solution]

Hi João Pedro

the physical memory of an ISO/IEC 15693 tag is organized in blocks (or pages) of fixed size (see ISO/IEC 15693-3 §5 VICC memory organization). Therefore, the various read or write commands follow this memory organization (e.g. Write Single Block command)

If you want to modify only one byte:

1. read the block containing the byte (e.g. Read Single Block command)
2. modify the value of the byte in your local buffer
3. write the modified block into the tag (e.g. Write Single Block command)

Also I would suggest you use the STSW-ST25PC001 Windows® PC software. It supports the CR95HF demo board and provides menu to read and write tag memory. It supports as well features of the ST25DV04K.

Rgds

BT

[JOliv]

Hi BT.

Thanks for your response. All right here... Thanks for the tip, i'm downloading the software. 

Regards,

João Pedro.