Read The Specific Address Of The User Memory Tag

Sensors NFC & RFID
1

Hi

Can we access the specific address of the user memory tag using the arduino example code “read_user_data” and SRTR? and if it can be done please tell me how. Thank you

2

What is the SKU for the product you are asking about?

3

SparkFun RedBoard - Programmed with Arduino dev 13975

4

The user bank is read into the buffer (myData), starting from position 0 up to the length of the user bank memory or the length of the buffer(myDataLength), whatever comes first. You can then offset to the right position in the buffer in the sketch to start to read your data. You can not provide a different starting point to the Sparkfun library as it will always start to read from position 0.

5

Is there any possibility to change the sparkfun library so that it can read user memory starting from 0x30?

6

Never tried but you could try it. In Sparkfun_UHF_RFID_Reader.cpp, function readUserData()

Change:

uint8_t address = 0x00; //Starts at 0

to

uint8_t address = 0x30; //Starts at 0x30

7

bank 0x3 is defined as user bank / memory is to be read. (bank 0 = reserved, bank 1 = EPC, bank 2= TID, bank 3 user). So setting the bank to 0x30, I don’t know what bank / memory is going to be read.

The only other check on user memory is in read_data : if(bank == 0x03) data[7] = 0x00; but that is to read the whole bank / memory.

Still I wonder why you would not read the whole bank and just read the part you want from offset 0x30 in the buffer. Maybe drop me a personal message.

8

I have adjusted the original Sparkfun library so you can now start reading the user memory bank from a specific address, with a specific length. You can also now perform a write starting at a specific address in the user memory bank. 2 new library calls have been added readUserDataRegion() and writeUserDataRegion(). I have added example13 to demonstrate reading and example14 to demonstrate writing. It is in a zip file on https://github.com/paulvha/ThingMagic/t … ib_special

This version also has the possibility to read the Nano internal temperature and apply the powersaving mode to the Nano.

9

thanks a lot ,sir