This thread has been locked.

If you have a related question, please click the "Ask a related question" button in the top right corner. The newly created question will be automatically linked to this question.


Other Parts Discussed in Thread: NFC-DATALOGGER-EVM, RF430CL331H

I recently purchased a NFC-DATALOGGER-EVM board to evaluate using NFC for a project. I also have an ACS122U reader which seems to be one of the most common USB card reader on the market. I am trying - so far unsuccessfully - to send the commands to set time and date etc to the nfc logger by modifying the code samples supplied with the ACS122U SDK. I'm wondering if anyone else has been down this path before me and has managed to communicate with the NFC-DATALOGGER-EVM using the ACS122U from a Windows environment, and would be willing to share some source code, or give me some tips. 

The precompiled sample programs provided in the ACS122U SDK will connect to the nfc logger and will read its status, but they don't have the flexibility to send time and date commands. The examples provided with source code can see the ACS reader, but just give errors when I place the NFC-DATALOGGER-EVM on the reader. I'm working on resolving this, but in the mean time would love to hear from anyone who has successfully configured the logger and downloaded the logged data from the NFC-DATALOGGER-EVM to Windows.



  • Hello Bradley,

    It looks like the device you purchased is for contactless payment applications. That would explain why it won't send those messages. I don't believe that device is intended to read/write general NFC tags. In any event, we don't use that device here so can't help you with it.

    I would recommend you use our NFC Reader/Writer solution.


    For details, see

    It comes with a GUI that you can use to read out the logged data into a .hex file.

  • Hello Ralph,
    Do you know of any commercial readers which are based on the TI chips used in the development board you recommended above? I was hoping to be able to use an off-the-shelf reader with the NFC product I am developing, rather than having to produce a reader as well. Hence the appeal of the ACR122U.
    Also, do you know what is happening when I present the NFC-DATALOGGER-EVM to my phone and it sends info to the phone? Is the phone continually polling, waiting for a card to appear? Is it sending APDU commands to the logger, or is the logger initiating events?

  • Hello Bradley,

    I'm not really familiar with other in the market products for generalized off-the-shelf NFC readers. I know at one point we tested with a Duali system successfully but I don't recall which model and they have quite a few.

    Something else to consider which I forgot to mention is that the Datalogger EVM which uses the RF430CL331H will require support of the WTX Extension request. That could be another shortcoming with the ACR122U.

    From a smartphone perspective, when NFC is enabled and the phone is unlocked (maybe newer models do it even in lock screen if the screen is on?), then it will periodically (1 second or less interval typically) for NFC devices. So yes it is continuously polling, though the duration and frequency of the polls are setup to conserve power very efficiently so you don't even notice that.

    All that is sent to start is the polling command, and only when a reply is received will further communication take place. That is when the APDU commands come into play.