TRF7964A: TRF7964A

Becky Gasser

Prodigy 60 points

Part Number: TRF7964A
Other Parts Discussed in Thread: MSP-EXP430F5529LP, TRF7970A

Hello,

I am using the TRF7964A with a Microchip PIC MCU in a tag reader. I am using reader/writer mode.

I am using the example code from TRF7970ABP_RFID_Reader_Demo.

I am able to identify and read ISO15693 tags correctly, but not Desfire/EV1 tags.

The PIC does not support recursion (which, in the example code, is used in the reading of the ISO14443A tags). As a work-around, I have changed the code so that those functions are enclosed in while loops and only exit when finished.

My question is, could the fact that I am not using real recursion be the source of my problem?

Thanks,

Becky Gasser

over 2 years ago

0 Andreas Mueller over 2 years ago

TI__Genius 14580 points

Hello Becky,

I'm very busy with other tasks at the moment, so it might take a while until I can analyze it.

In the meantime I suggest to leverage the existing documentation, listed on the product page (such as TRF7964A Device Errata, FAQ document and especially the related application notes like "MIFARE DESFire EV1 AES Authentication With TRF7970A").

Best regards,

Andreas.

0 Andreas Mueller over 2 years ago

TI__Genius 14580 points

Hello Becky,

had you have a chance to look at the application note "MIFARE DESFire EV1 AES Authentication With TRF7970A" and could it provide the information you need?

Which example code are you referring to, SLOA227 or SLOC297? SLOA227 comes with an application report for better understanding (NFC/HF RFID reader/writer using the TRF7970A (Rev. B).

What do you mean by "recursion"?

Best regards,

Andreas.

0 Becky Gasser over 2 years ago in reply to Andreas Mueller

Prodigy 60 points

Hello Andreas,

I have been moved to another project, but when I get back to this one, I will review what you have sent.

Thank you,

Becky

0 Becky Gasser over 2 years ago in reply to Andreas Mueller

Prodigy 60 points

Hi Andreas,

I already have "MIFARE DESFire EV1 AES Authentication With TRF7970A".

I am using the source code from sloc297c\TRF7970ABP_RFID_Reader_Demo\NFC.

The link for SLOA227 only contains TRF7970A-RW-1.03.00-windows-installer.exe, which does nothing.

By recursion I mean recursive function calls (a function that calls itself).

Thank you,

Becky

0 Andreas Mueller over 2 years ago

TI__Genius 14580 points

Hello Becky,

the TRF7970A-RW-1.03.00-windows-installer.exe is installing the "NFC TI Tool Version 1.8", which is the PC GUI for interacting with the TRF7970A, and it also installs the firmware source code for the MSP-EXP430F5529LP by default in folder C:\ti\nfc\TRF7970A_RW_1.03.00\examples\boards.

I just checked again the TRF7970A-RW-1.03.00-windows-installer.exe and it is working as expected. Maybe your PC is blocking all software installation.

Was the solution "MIFARE DESFire EV1 AES Authentication With TRF7970A" working for your setup?

Why do you want to repurpose sloc297c for it?

Best regards,

Andreas.

0 Becky Gasser over 2 years ago in reply to Andreas Mueller

Prodigy 60 points

The source code in sloc297c for ISO15693 works perfect for me (after I made adjustments for my particular project), but I cannot get the ISO14443A to work. I need to know if part of the problem could be the recursive function calls.

0 Andreas Mueller over 2 years ago

TI__Genius 14580 points

Hello Becky,

the recursion is required for the anti collision loop. So, it could be the root cause of your issues.

Best regards,

Andreas.

0 Becky Gasser over 2 years ago in reply to Andreas Mueller

Prodigy 60 points

I have rewritten the code so that I use a while loop to re-enter the functions.

For instance this:

do
{
sCollisionStatus = ISO14443A_runAnticollision(sUidProgress);
}while (sCollisionStatus == COLLISION_NOT_DONE);

instead of this:

sCollisionStatus = ISO14443A_runAnticollision(sUidProgress);

I do not know if my method takes longer than regular recursion, or if it makes a difference

0 Becky Gasser over 2 years ago in reply to Becky Gasser

Prodigy 60 points

Hi Andreas,

If I do not have any collision (only one tag is presented at a time) so i need anti collision?

Also, do I necessarily use all the cascades? Or maybe the tag only uses cascade1? I do not fully understand this process with the cascades.

Thanks,

Becky

0 Andreas Mueller over 2 years ago

TI__Genius 14580 points

Hello Becky,

the anti collision sequence is described in the ISO14443-3 spec. You can also leverage the application note "Implementation of ISO14443A Anti Collision Sequence in the TI TRF796x". Although it is for TRF796x, it still can give you an idea on how the anti collision works.

I think the anti collision is part of the application layer activation. If you would know the UID of a tag, then you could skip the anti collision loop and directly activate the PICC.

With ISO15693 tags you could directly start with a read or write command without addressing if you ensure to only connect a single tag at a time.

Best regards,

Andreas.

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TRF7964A: TRF7964A