Problem in coding-PIC18F controlling TRF7960 RFID IC

trf7960

hi,

I am working on RFID project.
I am using TI TRF7960 IC which is to be controlled by PIC18F4420.
During coding I am getting problem.
Kindly check the attachment and suggest me.

Thanks & regards,
Rajan

rfid ic

hi,

I get some success i writing the data to the RFID registers.
Instead of calling the function : openSPI, i directly write the hex values of
SSCON1 and SSTAT registers in the main program and
then call writeSPI function to send register address and again calling writeSPI to send data to be written in the respective register.
This time i have used "SPI with SS pin", means i also enabled SS pin while SPI interface.

But i am not able to read the status of registers by sending read command.

Regards,
rajan

trf7960 spi

hi,
On setting the trf chip status registers to Rf on and setting ISO control register.
Reader Ic does not show any response when i place tag in its vicinity.

Also simple carrier is observed at the antenna of reader.

Kindly suggest me .

plz


Regards,
Rajan

pic18f1320 spi

Hi,
are you sure your SPI communication is working correctly? Have a look at the SPI app note.

Tom

Hy..did you manage to fix ur problem?..i'm trying the same but with a different pic and i'm having problems with the programming. Any help would be great.

best regards

hi,
I was busy in some other projects.
Now I am able to detect the RFID tags only for Slot0.
PIC not able to switch to next slot enquiry.

soon I will upload my code.

Rajan

hi all,

I have attached the schematic and code related to TRF7960.

I am able to detect RFID tags with slot 0 , i.e LSB is 0.

In my code, once pic execute the interrupt routine, It does nt come out
of it so it never respond to next interrupt (time out).
Kindly hepl me.:|

Regards,
Rajan

Rajan,

I am trying to interface the TRF7960 with PIC24F controller.I face similar problem as explained by you.I get an TX successful interrupt when I send a ISO request packet.
I am waiting for the RX complete / timeout IRQ from TRF.But I am not able to get the interrupt.

Please let me know if you have fixed this problem.

Thanks And Regards,
Shenoy

hi,

As per TRF7960 supporting document SPI interface.

dummy clk cycles are required to read the spi data.
Have u implement this dummy clock cycles while reading data???
Or it may be that ur RFID tags may not belong to slot 0 and
you are also facing the same problem like me, i.e switching to next slot and new inventory command.

Regards,
Rajan

Hi Rajan,

I am trying to read the UID of the Mifare card.At present I am able to sense the card. i.e I am able to get 0x40 in Interrupt handler function.(If interrupt is due to End of RX, this means that the response (from the tag) is received in the FIFO without
any error/collision).

I have implemented dummy reads and all are as per TI spi errata document.

Please let me know if you have any inputs.

Also if you can share your number,we can talk to each other.

Thanks And Regards,

Shenoy.

I think only IRQ register read in SPI mode require the extra dummy read cycle...
I'm also interfacing TRF7960 with P89V51RD2...
I have made TRF7960board by myself...
I think there is some problem in connection because it is very difficult to solder QFN package...
I'm also unable operate that IC..
u guys are doing graet job...

Hello

I have developed a PCB for the TRF7960 and I am interfacing it with a 18F4585 PIC. I have developed it as equal as I could, to the evolution board from TI.
Now I can interface with the TRF, read and write the registers but I can’t receive the UID from the tag. I thing that the problem is that I only get a 68 kHz on the SYS_CLK even if I change it on the 09 register. Could it be related with the crystal or with the software? I always come from the power down with both EN1 and EN2 high but the SYS_CLK is always 68 kHz. I have switch the crystal to a new one and the problem is there anyway.
I also can’t get the RX1_IN1 and RX2_IN2 with the 3VPP voltage, I only get a 1,57 V on each other

What should I do about it?
Could it be a wrong crystal? Or do I forget about it and try to receive the tag UID anyway? Do I have the line of RX1 and RX2 to long and the TRF can’t stabilize?

My crystal is this **broken link removed**

Frankly I don’t know what to do and what could be the problem. I never got the 13 MHz on the SYS_CLK.

This is my PCB

Thank you in advance

Hi, i've set up a TRF7960 pcb to read a Mifare card. I'm using a pic18F2550 with SPI mode and i've already complete an anticollision sequence following the ISO14443A standard to get the complete UID of the card and to select it.

Now, I should start the mutual authentication with the card, Im able to get the tagNonce of 4bytes but then i should reply doing the framing manually because the trasmission is encrypted and also the parity bits are encrypted, so I must switch to the DIRECT mode bypassing the protocol implementation in the TRF7960.

Anyone have the same problem? we can work togheter! let me know

I am using pic18F2550 with parallel mode for the TRF7960 and can't read any 15693 tags.

hi,
Do u already know the IDs of Tags(based on ISO15693) that you have?
I am asking this question becoz, if u know the IDs inadvance and if one of the tag has ID with LSB (least Significant Bit) =0.
You should debug your reader with this tag first.

If you are able to recover the ID of this tag, then there may be a problem that
"next slot" command is not proprely implemented.

else there may be a timing issues .

Best of luck
Rajan

axxe said:

Hi, i've set up a TRF7960 pcb to read a Mifare card. I'm using a pic18F2550 with SPI mode and i've already complete an anticollision sequence following the ISO14443A standard to get the complete UID of the card and to select it.

Now, I should start the mutual authentication with the card, Im able to get the tagNonce of 4bytes but then i should reply doing the framing manually because the trasmission is encrypted and also the parity bits are encrypted, so I must switch to the DIRECT mode bypassing the protocol implementation in the TRF7960.

Anyone have the same problem? we can work togheter! let me know

Click to expand...

Dear axxe,

I'm studying to design a HF RFID reader uses the TRF7960, this reader can read the card with mutual authentication. So the same to you, we need to join in the direct mode to manual data and command before send to the tag. I dont know how about the result of your design. In the datasheet of TRF7960, if we use the direct mode, we need the input modulation to the MOD pin, it means we need to design a external modulation?? pls help me.

Hi MTicdrec,

I've already fixed everything with the TRF7960 and the Mifare cards.

All what you have to do is to study how each single command is made, you have to know each BIT which you have to send to the card.

After entering the DIRECT MODE 0 you can modulate the signal with the corrects pulses according to the ISO14443A protocol.

So yes, you have to design an external modulation. In my case I did everything by software.


If now you are able to send a simple REQA command to the card, I would suggest to try to send the same command in DIRECT MODE 0.