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CN0303 for evaluation board of the acquired data

Hi ALL.

I have check the operation of the ADXL001 using the CN0303 evaluation board.


Please answer the following three questions.

1.As a result of to save the results of the measurement in "Frequency mode", the following figure of data has been output.
A column I think Amplitude, but please tell me the meaning of the B,C columns.

2.A/D converter(AD7476) that is implemented on the board is 1MSPS, but it has become about 60kSPS If you look at the data.

Please tell me how to change the Sampling Rate.

3.If you save the data by measuring from "Acceleration Display", A ~ C column will become all "0".

Is there a way to save the data?


Best Regards,

Hara

  • Hello Hara,

    I will see if the developer is in a position to help with this inquiry, but we need to keep in mind that this software was provided to be a starting point for others to customize for their needs, not as an offer for software development services.  The 60 kSPS was selected to provide a Nyquist zone of up to 30kHz, which is adequate for most applications for a sensor that resonates at 22kHz. While I can certainly see the value of the faster sample rate for shock capture, that was not the original intent for this package.

    Best,

    NevadaMark

    FormerMember

  • Hello Hara,

    Column A is magnitude, as you mentioned.

    Column B is 'dF' or the frequency interval which, I believe, is only calculated once.  This is why you see '0' in every cell preceding the first.

    Column C is the actual ADC code which is read during the sampling.

    The Acceleration Display actually initiates a different function in the software.  It does not calculate the FFT, rather it just calculates the acceleration.  So when you try to save data, it does not populate the necessary arrays with information... as a result you see all '0's.

    As Mark said, we intend the software as a starting point.  I am extremely busy but could find some time to make this one adjustment for you if that is helpful!

    Cheers

    Neil

  • Hello Hara,

    I am recompiling the software with a few changes for you.

    I moved the sample data button and it will now trigger both functions simultaneously so you will not encounter the problem you ran into before.

    The save data function now provides column headers as well.

    Please wait 60 minutes before downloading the software from the ftp site.

    /users/cftladm/cftl/CN0303/1.0.0

    You can access the clock frequency and other develop controls in a hidden tab. 

    If you navigate to the 'SDP Board Information' tab and type 'CN0303' into the 'Date' field, this hidden tab will become visible.  Expand the labview window to the right to view the new tab.  I resized the labview window and it is actually a little large when this hidden tab is revealed, I apologize for that.

    Cheers
    Neil

  • Hello Neil.

    Thank you for me to program changes.

    After downloading the software, I was able to check the operation.


    1.By adjusting the SCLK and Frame frequency, it was possible to change the sampling frequency.

    But, GUI of Sampling Frequency (58823) remains fixed.Is it possible to change?
    You can change the LPF it is because I want to try to confirm the above frequency response 22kHz.
    2.I have set the Frame frequency to 100Hz in 256Samples (dF = 229.77).
    Why "Save Data" of the observation of the results sampling rate is either would look like is fixed?

    3."Acceleration Display" I think are Sampling at about 450 ~ 750Hz interval independent of the Frame frequency.

    Is it possible to change the sampling interval?
    Although I do not think I be able to save the Data of "Acceleration Display", so it is correct?

     ※Waveform is when Acceleration observation.

     

    Best Regards,

    Hara

  • Hi ALL.

    For the above 1., I understand that is a special request.
    However, we want to measure in the software that you change the sampling frequency up to 100kHz.
    Could you change the software?

    Best Regards,

    Hara

  • Hello Hara,

    I have made several modifications to the software and uploaded it to the ftp (ftp://ftp.analog.com/pub/cftl/CN0303/1.0.0/) for you.  Now when you change the sampling frequency you will see a change in the time domain (X-axis) of the acceleration results.  Furthermore, you now have access tot he FFT controls.

    Please let me know if this is what you were looking for and if I can help you in any additional ways.

    Cheers

    Neil