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TRF7960: i am always getting irq status as 0x80,0x01 and 0x00

Part Number: TRF7960

we are doing trf7960 based security project. the main controller is pic18f452 .it configured as  ook 100%,ISO15693.

but i am always getting irq status as 0x80,0x01 and 0x00 with Tag-It H inlay transponder.  we used spi communication

between TRF7960 and MCU.

what could be the problem? how i can handle it.

  • if you are sending 16 slot inventory (sending 0x06 0x01 0x00) and you are then using a tag which does not end in 0, and this would be normal. (as this is indicative of a no response in slot 0)

    if you change it to single slot inventory you will get a response. (send 0x26, 0x01, 0x00, for example)

    if you want to continue with 16 slot, then follow the process needed to retrieve the UID, which means you need to follow with 15 EOF/Slot markers

  • i tried with single inventory command still i am not getting UID of tag. after that i checked with anticollision it does not give response except irq status as 0x80,0x01,0x00. pl.if other causes for getting UID.
  • couple things to check:
    are you getting EORX at all? (if not, then you will need to make sure you do the dummy write to the FIFO after clearing the EOTX IRQ)
    covered here in page 6 ==> www.ti.com/.../sloa140.pdf

    is the tag actually an ISO15693 device (who is vendor)

    is your antenna tuned? can you send a schematic of what you have created and include your tuning of your antenna details?
  •  Dear Josh Wyatt,

    i didn't get the EORX at all. just i wrote code as sloa140 where one dummy cycle is needed for clearing irq. 

    we purchased tag15693 (TEXAS INSTRUMENTS)through element14.  i attached scan copy of rfid kt.

    please check and give advice if any modifications.RFID.pdf 

  • couple things on your schematic

    1. put the coil value in your drawing - from your values it looks like you are around 1.3uH in value

    2. MOD and ASK/OOK need to pulled to ground with 1kOhm (each)

    3. I/O_0, I/O_1 and I/O_2 need to be handled according to table on page 24, here ==> 

    then EN2 needs to be either pulled high or low - a voltage divider is not OK here. (maybe you mean either R76 or R79 is populated, which the other one is DNP/DNI)

    once you fix the hardware - then you can focus on your software. You might want to next provide (after you fix your hardware) the SPI logic captures which show the register configuration, then teh command you send, then the EOTX IRQ handling (with FIFO clear as previously discussed), then your EORX, with FIFO read, which will come once the preceding is correct. 

  • Dear Josh,
    After fixed the hardware , I am still getting same response from module. we are not equipped with SPI analyser for capturing various rf settings.please any method to capture.presently i have tektronics TDs2014 100mhz oscilloscope is there.
    thanks
  • lets check the TX out first - see the attached and check with your o'scope to make sure you have actually turned on the transmitter. 

    2185.TRF79xxA_Test points_05_2013.pdf

    also, if you can send a picture of your tag and antenna relationship, that would be good  -

    then you can hook up to at least the MISO, MOSI, DATA_CLK and Slave Select lines to let us see what you are actually sending - in that case we will have to pick out the bits, but that is OK - this is what we had to do before logic analyzers came around. 

    this is from LSA, on the TRF7960, but you can use for reference, as the scope should look the same really -

    single slot inventory

     EOTX with FIFO reset done correctly

    EORX

  • Dear Josh,

    i have taken pictures of various signals. pls.check and give soultion.

    1.TRF7960 pin5 (TX  OUT)

    2.DC blocking capacitors and L1

    3.In between L1 and L2

    4.impedance matching point(Rf test port)

    5.Antenna Coil Signal

    6.SPI interface Signals(SPI-1 and SPI-2)

    7. RF tags what we are using

    Please check above pics.  please give reply as early as possible. because i am stucked in this project.

    Thanking for responses. 

  • Dear josh

    please check wave forms and give needful information.

    thanks and regards

    satya.ch
  • Dear Josh

    could you checked these wave forms and anything is missing/mistake.

    thanks and regards

    satya.ch

  • looks like the MOSI like is pretty noisy and your MISO line never transitions low.

    if you can get the noise fixed and get a cleaner scope capture or use LSA, this would help - i think the noise might need to be fixed first -
    do you have any pictures of your setup and your repaired schematic?
    also, make sure you have the registers configured correctly and you are sending the single slot command for this troubleshooting time.


    set register 0x00 to 0x21 (if running off +5VDC), set register 0x01 to 0x02 (for ISO15693), then send
    0x8F, 0x91, 0x3D, 0x00, 0x30, 0x26, 0x01, 0x00

    then see what the EOTX looks like and your EORX and IRQ status, FIFO etc.