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EVM430-FR6043: Noisy measurements with the evaluation board

Nicolas Coinin
Prodigy 10 points
Part Number: EVM430-FR6043

Hello,

I'm using the EVM430FR6043 for a gas meter configuration and i have a noise problem. I use 200 kHz transducer (AT200 from AIRMAR) spaced of 8 cm. After following the user guide and also flash the binaries to the evaluation board I always have a noise issue.

Here is my pin configuration for the board, one of the noisy ADC capture (noise in red) and noisy spikes ATOF and DTOF at 0 flow :

I tried multiples configurations, more and less amplification, differents distances, gap measurements, reflashing the board, redownlaoding the GUI and even all that on a second EVM430FR6043 board and on a second PC. I always have the issue. Then i noticed that when there is no wire, the noise is about +-20 amplitude counts on ADC capture but when i plug one wire on X1 or X2 on J5 or J6 but not connected to a tranducer, I already have the noise. Here is a screenshot of this situation :

(if i connect one DNS wire i have the noise also on this channel)

My guess is the noise come from the USB cable but at such a high level I don't understand why and I don't know what to do ?

Do you have any suggestions ? (I can't test now your suggestions because I'm on vacation until the end of June but I will read and answer on the forum)

Best regards,

Nicolas Coinin

  • 0
    TI__Guru 59951 points

    Hello Nicolas,

    Sorry for the delay in response.  I hope the weather is beautiful where ever you are and you are enjoying your vacation.

    When you return, can you take a screen shot of your GUI "Parameters" and "Advanced Parameters" so I can see your settings?

  • 0 in reply to Dennis Lehman
    Prodigy 10 points

    Hello,

    Of course, i'll come back the 27/06 with screenshots.

    Regards,

    Nicolas C.

  • 0 in reply to Nicolas Coinin
    TI__Guru 59951 points

    Hi Nicolas,

    I would expect noise. You are creating an antenna if you only connect a piece of wire to the CH0 or CH1 input.  Have you tried shielding the transducer wires by wrapping the entire length of wires in a braided shield, copper tape or aluminum tin-foil and connect to ground?  Also, to see if the noise is from USB, power the board from +5v bench supply?

  • 0 in reply to Dennis Lehman
    Prodigy 10 points

    Hi Dennis,

    I have not tried shielding my wires yet and for the external supply i had problems to make it work, maybe I have not follow the instructions of the user guide correctly. I'm working with other stuff this week but I will try shielding my wires before the end of the week and also give you screenshots of my GUI parameters.

    Thanks for your time,

    Nicolas

  • 0 in reply to Nicolas Coinin
    Prodigy 10 points

    Hello Dennis,

    I've tried shielding my wires and for one tranducer it worked I have no noise anymore but for the other one, the noise persists. Maybe I should try other wires and reshelding it.

    Here are my GUI parameters :

    Regards,

    NIcolas

  • 0 in reply to Nicolas Coinin
    TI__Guru 59951 points

    Hi Nicolas,

    It's been a couple of days and I was curious if you had success shielding both transducers?  Can you share a photo showing how you shielded the transducers?

  • 0 in reply to Dennis Lehman
    TI__Guru 59951 points

    Hi Nicolas,


    It's been a while since we have heard from you, so I'm going to assume you were able to move forward with your project.
    I will mark this posting as RESOLVED, but if this isn’t the case, please click the "This did NOT resolve my issue" button and reply to this thread with more information.
    If this thread is locked, please click the "Ask a related question" button, and in the new thread describe the current status of your issue and any additional details you may have to assist us in helping to solve your issues.

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