Plotting

MegunoLink Pro can plot data sent from a microcontroller by parsing specially formatted messages. Currently two types of plots are supported:

  • Time plots, which are similar to a chart recorder, showing a number plotted against time. Time plots support auto-scrolling, which keeps the edge of the time axis set to the current time so that old values scroll off the left of the plot. All the data is retained though. You can zoom out, or pause the plot, and see the earlier data.
  • X-Y plots, which take two values from the microcontroller. One for the x (horizontal) axis and the other for the y (vertical) axis.
Plot samples

Data sent from an Arduino program is graphed on a time plot (left) and an x-y plot (right) using MegunoLink Pro

Both types of plots support multiple series, so you can show graphs of several different values at the same time. They both also support channels. Channels let you use several different plots in the same project, with different data going to each.

The easiest way to send data to the plots is using the TimePlot and XYPlot classes in our Arduino Library. If you are not using an Arduino compatible device, or prefer to send raw messages, the plotting message reference describes the message format expected by the MegunoLink Pro plot visualizers.

As well as sending plot data, both time and xy plot libraries support setting series styles, axis labels and plot titles.

Articles, and further documentation, may be found at:


28 comments on “Plotting
  1. Lowell Bohn says:

    Hi,

    I can’t get these commands to work for the XYPLOT. Is there something I’m doing wrong?

    Serial.println(“{XYPLOT:Spectrum|Clear}”);

    Serial.println(“{XYPLOT:Spectrum|set|title=Spectrum}”);
    Serial.println(“{XYPLOT:Spectrum|set|x-label=nM}”);
    Serial.println(“{XYPLOT:Spectrum|set|y-label=PMT Current}”);

    Cheers,

    Lowell

    • Phil Rowe says:

      Hi Lowell, interesting. I think this is a bug that has crept in. Because you are not actually plotting any data nothing redraws and the labels are not being updated. If you click on the plot after these commands go through it should trigger an update. Also just in case, make sure you have the right connection selected for your device in the XY Plot visualiser (far left on the top menu).

      Let me know how it goes.
      Phil

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