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protocol for reading temperature from TIDM-RF430-TEMPSENSE

user4926502
Prodigy 40 points
Other Parts Discussed in Thread: TRF7960, TIDM-RF430-TEMPSENSE, MSP-FET

Hi there,

I am recently working on a project measuring temperature using RFID. As a first step, I would like to explore the possibility using TIDM-RF430-TEMPSENSE reference design. I noticed that TI offered to using TRF7960 EVM and the accompanying GUI to communicate with the tag. However, I would like to know the underlying details of the iso15963 command needed for reading the temperature.

thank you for any help!

min 

  • 0
    TI__Guru*** 128125 points
    Hello min,

    We have a software example for reading the patch with a LaunchPad+BoosterPack setup which is documented here: www.ti.com/.../sloa233 - the software can be downloaded from the app note.

    There are flow charts in Section 8 corresponding to the sloa233 software, and the code provided is heavily commented to explain the purpose for each command being used to communicate with the tag. Please refer to these collateral resources for your questions.
  • 0 in reply to Ralph Jacobi
    Prodigy 40 points
    Hi Ralph,

    Thanks you much for the info. The example is very helpful.

    Also, I wonder whether you could do me another favor: what is the typical raw value in block 9 when using a same configuration as in the example. I am asking this because I think the value I got was far from right: Based on my calculation, the voltage reading for reference resister should be close to 8738 (DEC). However, my reading was very different. I wonder whether you have any suggestion?

    thanks,

    Min
  • 0 in reply to user4926502
    TI__Guru*** 128125 points
    Hello Min,

    Would be helpful if you could provide your readIng? Did you make sure it's in Dec or Hex in the compiler? Where did you put a breakpoint to check on the result?

    A quick test I did was to put a breakpoint on line 198 of nfc_app.c which is where NFC_calculateTemperature is called. Looking at the ui16RefResReading value I got here, I got a result around approx. 0x2200, or 8704 decimal (as you calculated).
  • 0 in reply to Ralph Jacobi
    Prodigy 40 points

    Hi Ralph,

    The reading problem is solved. I didn't notice that the order is reversed.

    However, I am running into another issue. One of the my temperature tag (originated from TI) responds with fix ADC readings every time, and when I checked closely, I realized that I could not write anything into block 0 (I haven't try to write any other block). Same thing happened when I used the android app to read the tag. I wonder whether you have any idea what was wrong?

    thanks,

    min 

  • 0 in reply to user4926502
    Prodigy 40 points
    update: for some unknown reason, block 0 and 1 of the tag were both user-locked. I wonder is there anyway to fix this? or do this mean that the tag is done? thanks
  • 0 in reply to user4926502
    TI__Guru*** 128125 points
    Hello,

    From what I saw on prior E2E posts, there would be a way to fix this if you can JTAG into the device to re-program it.

    The line of code you'd need to execute is: initISO15693(CLEAR_BLOCK_LOCKS);

    JTAG'ing in would be very tricky though, as you will not only need to solder/wire out the JTAG on the patch, but also use level translators between the patch JTAG and the MSP-FET... not at all trivial.

    Frankly if you want to save money, you probably could try and return it and claim it faulty... (you didn't hear that from me).