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passive rfid reader

Giorgio
Intellectual 350 points
Other Parts Discussed in Thread: TRF7962A, TRF7963A, TRF7964A, TRF7970A, TMDSRM48HDK, DLP-7970ABP, HALCOGEN

Hello all,

Can you recommend a passive RFID tag reader that i can interface with the TI RM48L ?

Thanks again

Giorgio 

  • 0
    TI__Guru 72500 points
    I moved your thread to the NFC/RFID forum as they will be better able to help you.
  • 0 in reply to Bob Crosby
    TI__Guru*** 131490 points

    Hello Giorgio,

    What RFID technology are you looking to use? High Frequeny (HF)/NFC? Low Frequency (LF)? Ultra High Frequency (UHF)?

  • 0 in reply to Ralph Jacobi
    TI__Guru* 91166 points
    maybe the better question to answer here is: what is the goal of using RFID with the Hercules MCU?
  • 0 in reply to Josh Wyatt
    Intellectual 350 points
    Hi Josh, Hi Ralph,

    Thank you for your answers.

    I'm new to RFID technology so I'm still trying to understand what is the right passage tag for me and how to read it.

    Basically, the TI RM48L is used as main microcontroller in a device, to this device can be connected directly or indirectly different tools, some or them very small that are made by just plastic.
    The device should be able to identify the type of tools connected to it and I was thinking to place a small RFID passive tag on these tools, so that having an RFID reader connected to the RM48L, I can identify them.

    Thanks for your help, I do admit I'm still confused on this topic.

    BR

    Giorgio
  • 0 in reply to Giorgio
    TI__Guru*** 131490 points
    Hi Giorgio,

    Thanks for those details. Based on your description, I think HF RFID/NFC would work for your use case. I think the best obstacle you will face is attaching tags to each of the different tools. Particularly the small ones.

    From a tag standpoint, you will want to look at either ISO15693 or ISO14443A.

    Approximately how small would the small plastic tools be?

    We have a 4mm x 4mm form factor tag which may be possible to use for those if they are quite small: www.ti.com/.../rf37s114.pdf

    The downside of this tag is that the read range can be very low compared to other HF RFID tags so you'd need to customize your RF design to help support it. To give you some ideas on read ranges, please see this app note: www.ti.com/.../scba035a.pdf

    Another thing to consider from the tag standpoint is the environment around them. You mentioned plastic tools, but are there any metal tools? HF RFID uses magnetic fields for communication and metal will detune antenna frequencies and interfere with communication.

    For the reader side, you can begin evaluation with the TRF7970A which is our fully featured NFC/RFID Reader/Writer that also supports Peer to Peer and Card Emulation. This device is where we focus all new development for the latest software examples and app notes. Once you are done prototyping though, you can then move to a lower cost specialized RFID reader chip. For single protocol, we have parts such as TRF7962A and TRF7963A for ISO15693 and ISO14443 respectively, or you can use the TRF7964A for multiple reader protocols.

    For evaluation of the reader side, please see our NFC Reader/Writer app note: www.ti.com/.../sloa227.pdf
    For the hardware related to that app note please look into this eval kit: store.ti.com/nfclink-bndl.aspx
    And for a TI-RTOS ported firmware example which you could migrate over to RM48L please see: www.ti.com/.../TIDM-TM4C129XNFC
  • 0 in reply to Ralph Jacobi
    Intellectual 350 points
    Hi Ralph,

    Thank you very much for your answer, it make me understand better the direction to move.

    4x4mm or 5x5 mm should be an ideal size for the kind of plastic tool they have to be attached too.
    No metallic part are present nearby the device or in the device itself. The only risk is that the tags could get wet by water or cleaning fluids, so I would need to make sure they are not exposed.

    The maximum distance between the device and the plastic tools is no more than 40cm , so I think that placing the reader in the device in the proper position would avoid any distance problem.

    Sorry, an other question. I would like to write only once in the RFIDTAG data like part number of the tool, what is the best way to do it? I guess is it during production?

    I need to check the cost of the 4x4mm , the plastic tools they are going to be attached cost, are quite cheap, so I will need to make sure it doesn't impact on the final cost too much.

    Thanks again for your help.

    Giorgio
  • 0 in reply to Giorgio
    TI__Guru*** 131490 points
    Hi Giorgio,

    Your distance comment makes me a bit concerned.

    Ignoring the tag you are using, just for HF RFID as a whole, 40cm is a long distance. Usually you are looking at the 5cm range, and up to 10cm for very well designed applications.

    With that said, I posted this app note for a reason: www.ti.com/.../scba035a.pdf

    The 4mm x 4mm tags are very small and having such a small antenna limits the RF communication range a lot. You are looking at 1-1.7cm range with these tags, not even close to 40cm.

    Will the device be physically attached to the plastic tools? If so, you could wind an antenna around the location where the plastic tool is attached to minimize the range between the HF RFID Reader antenna and the presence of the HF RFID tag.

    As far as the writing of data is concerned, yes you can do that during production. Just have an RFID station where a Reader/Writer will write the data to the tag. If you use ISO15693 tags (which the 4mm x 4mm tags are!) then you can also use a lock block command to keep the data permanently stored so no one can overwrite it - I think that would be very useful for your use case.
  • 0 in reply to Ralph Jacobi
    Intellectual 350 points

    Hi Ralph,

    thank you for your help, I really appreciate it.

    Looking at the design, I could have a minimum distance between the reader and the antenna at about 5 to 6 cm.

    Does the antenna help to extend the range of the reader? I mean, if I place the antenna inside the device, will it help to detect the rfid even if it is more than 1.7cm away?

    Thanks again

    Giorgio

  • 0 in reply to Giorgio
    TI__Guru*** 131490 points
    Hello Giorgio,

    The antenna doesn't extend the read range, but it can be placed to minimize the distance between it and the tag. The tag will still need to be in range of where the antenna is at.

    There are a few ways to design RFID antennas. A common way is to include it in the PCB and just connect it to the NFC Transponder chip with traces. You can do other methods.

    One would be to use an external RFID antenna which connects to the PCB of the NFC transponder chip with a U.FL or SMA connector. This would allow you to place the RFID antenna as close to the surface of your enclosure as possible to minimize the distance between the coil of the RFID antenna and the presence of your RFID tag.

    By doing this, you can place the antenna in a location that it may not be feasible to have the PCB located at.
  • 0 in reply to Ralph Jacobi
    Intellectual 350 points
    Thanks again for your help,

    Just to have a rough idea, to have a range of about 10 cm, what size of passive rfid should i use?

    Thanks again

    Giorgio
  • 0 in reply to Giorgio
    TI__Guru*** 131490 points

    Hello Giorgio,

    That will also depend on the antenna size and output power of your NFC reader as well.

    Just to give you a general idea, the TRF79xxA can output maximum 200mW of power w/ 5V input, and 70mW with 3V input. To maximize the range from the reader side, you will want to source the TRF79xxA with 5V.

    For an idea on read range with a reader at 200mW output and a 55mm x 40mm antenna with a variety of RFID tag sizes please see this document: 5661.TRF796x EVM Read Ranges.pdf

  • 0 in reply to Ralph Jacobi
    Intellectual 350 points
    Thanks again,
    So, just to be sure , i'm considering this target board

    www.ti.com/.../trf7970atb

    to use with the RM48L dev board TMDSRM48HDK

    www.ti.com/.../tmdsrm48hdk

    Is it easy to interface them?
    Is it easy then, having RFID tags, write and read them?

    Thanks again

    Giorgio
  • 0 in reply to Giorgio
    TI__Guru* 91166 points

    Giorgio -
    you may also want to consider looking at the Hercules LP + TRF BP 

    www.ti.com/.../launchxl-rm42

    www.ti.com/.../DLP-7970ABP

  • 0 in reply to Josh Wyatt
    TI__Guru*** 131490 points

    Giorgio,

    I agree with Josh on the LaunchPad and BoosterPack combo. It doesn't look like that DK board you linked has EM headers spaced correctly for the TRF7970ATB. The LaunchPad and BoosterPack would be a better combo.

  • 0 in reply to Ralph Jacobi
    Intellectual 350 points
    Thank you!

    So the Lauch Pad

    www.ti.com/.../launchxl-rm42

    have the connector for the target board

    www.ti.com/.../trf7970atb

    ?

    Is than easy to integrate example software to write and read passive RFID tag?

    Thanks again

    Giorgio
  • 0 in reply to Giorgio
    TI__Guru*** 131490 points

    Hello Giorgio,

    No, the LaunchPad does not have connectors for the Target Board. You need to get the TRF7970A BoosterPack which is: http://www.ti.com/tool/DLP-7970ABP

    There is no existing software example on Hercules for this, but you can port one of two firmware bases:

    Fully Tested NFC/RFID Reader/Writer with robust error handling:
    - App Note: www.ti.com/.../sloa227.pdf
    - Firmware: www.ti.com/.../sloa227
    Low footprint basic RFID Reader with basic error handling, designed for evaluation not production:
    - Basic summary: e2e.ti.com/.../493678
    - Firmware: www.ti.com/.../sloc297

  • 0 in reply to Ralph Jacobi
    Intellectual 350 points
    Thank you,

    I'm going to order the Launchpad and the booster pack.
  • 0 in reply to Ralph Jacobi
    Intellectual 350 points
    Thanks again for your help,

    Can you please suggest a basic Halcogen configuration to start the porting for the BoosterPack?

    Thanks again

    Giorgio
  • 0 in reply to Giorgio
    TI__Guru*** 131490 points

    Hello Giorgio,

    I'm not familiar with Halcogen, so I am not sure about the different configurations. I don't think one has been made specifically for the DLP-7970ABP, but any configuration that would apply to BoosterPacks that follow the TI BoosterPack standards would work.