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Threshold checking for a realtime signal

  • Hi
    I have a realtime signal from a sensor. I need logic to implement a masking time once the signal is above a threshold. Here, masking time is a time period masked for any threshold checking. This is how I can differentiate positive and negative pulse As shown below:
    (during a postive pulse there is a negative-going side but it should not detect as a "negative pulse").

    Lets say the masking time period is 0.5 seconds in my case. How do I implement this logic in Qt.
    I can get the current time and compare for a threshold as shown below, but don't know how to mask for threshold checking for a period of time (say 0.5sec)

    static QTime time(QTime::currentTime());
    // calculate two new data points:
    double key = time.elapsed()/1000.0; // time elapsed since start of demo, in seconds
    if(a_vertical> onThreshold) // is this check correct for masking time?
            ui->rdo_btn_vertical->setStyleSheet(StyleSheetOn1); // On  LED
            lastKey = key;
            ui->rdo_btn_vertical->setStyleSheet(StyleSheetOff1); // Off LED

    Any ideas / feedbacks are welcome

  • Let's start with the basics: do you get any measurable values from the port the signaling device is connected?
    If so, based on your drawings, knowing the threshold value:

    • assume threshold is zero.
    • treat all the values below the threshold (zero) as negative in relation to threshold.
    • accordingly, all the values above threshold (zero) as positive in relation to threshold.
    • sum all those up.
    • if value is positive you have negative pulse, otherwise negative.

    But that assumes that you have measurable values from the sensor + that drawings represent accurate tendencies.

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