M24SR corruption - Possible to restore to factory defaults?

[stijn]

Posted on October 15, 2015 at 19:04

Hello,

I'm working on a project for simplifying commissioning of networks using NFC.For a very basic demo I'm using an Arduino communicating over I²C and an NFC enabled smartphone.Simply put: I read the old value from the NDEF file, next I write the new one. After this is done, the GPO_pin has gone high. Off this flank the Arduino gets an interrupt that reads out the new value over NFC. Now this works for a while, but after a while, I only get empty NDEF messages back over I²C. After this the smartphone doesn't even recognize the tag as an NFC Forum Type 4 tag anymore.I'm lost on what can cause this corruption? And is there a possible way to fix this?Any way would be greatly appreciated.

[stijn]

Posted on October 16, 2015 at 17:45

These are the replies I'm getting over I2C from the M24SR chip. Almost everything works as it should, except for reading the NDEF length and message. All the values are in HEX.

Select NFC T4 app2 90 0 F1 9Select CC file3 90 0 2D 53Read CC length2 0 F 90 0 44 45Read CC file3 0 F 20 0 F6 0 F6 4 6 0 1 20 0 0 0 90 0 A9 F3Select NDEF file2 90 0 F1 9Read NDEF length3 FE FE 90 0 81 41Read the NDEF message2 6A 80Deselect M24SR on the I2C-busC2 E0 B4

[JP Miller · Accepted solution]

Posted on October 26, 2015 at 16:09

Hello,

Indeed the tag has gotten in a non coherent state with respect to the NDEF file. I would recommend if possible in your application to rewrite the NDEF file, which would restore the proper state in the tag and make it usable again. Best regards, Have a good day.