Arduino Serial Plotter Scale

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Does anyone know how to fix the Y-axis on the serial plotter? I am trying to plot the output of a gas sensor which produces a value of between .15 and 2.5 and ideally I would like the axis to not autoscale and be from 0 to 5. Currently it seems to default to -6 to +6 which makes the changes in the plot line rather small.

Arduino Serial Plotter Scale Instructions

The Arduino Serial Plotter only supports one Y axis. An alternative would be to capture the data into a file as CSV data and use some other software to plot it - you could import the data into Excel / LibreOffice, or (as I prefer for quick graphing) use something like GnuPlot (or whatever is similar for your chosen OS). Oct 28, 2019 Hi, Awesome work! Well done.I have used Arduino for 2 years,I have made many interesting projects.I wanna thank your team with fantastic work. But,I also met questions When I use the serial plotter, I want to extend the display range of.

I have tried sending it 0 and then 5 as the first voltages but this doesn't seem to help. Ideally it would be incredibly useful if you could set the upper and lower axis on the plotter screen itself in a similar way to setting the baud rate. Also the ability to turn off auto-scaling would be very handy as I almost never want the graph to autoscale.

Has anyone a way of fixing the Y Axis values, and if so can they help here? I have searched the forum and couldn't find an answer.

Thanks in advance.

If you use Arduino, perhaps to handle the lower-level driving work of your DIY Robocar, you may have noticed the Serial Plotter tool, which is an easy way to graph data coming off your Arduino (much better than just watching numbers scroll past in the Serial Monitor).

You may have also noticed that the Arduino documentation gives no instructions on how to use it ¯_(ツ)_/¯. You can Google around and find community tutorials, such as this one, which give you the basics. But none I’ve found are complete.

So this is an effort to make a complete guide to using the Arduino Serial Plotter, using some elements from the above linked tutorial.

First, you can find the feature here in the Arduino IDE:

It will plot any data your Arduino is sending out in a Serial.print() or Serial.println() command. The vertical Y-axis auto adjusts itself as the value of the output increases or decreases and the X-axis is a fixed 500-point axis with each tick of the axis equal to an executed Serial.println() command. In other words the plot is updated along the X-axis every time Serial.println() is updated with a new value.

Arduino Serial Plotter Scale

It also has some nice features:

  • Plotting of multiple variables, with different labels and colors for each
  • Can plot both integers and floats
  • Auto-resizes the scale (Y axis)
  • Supports negative value graphs
  • Auto-scrolls the X axis

But to make it work well, there are some tricks in how to format that data. Here’s a complete(?) list:

  • Plot one variable: Just use Serial.println()

Serial.println(variable);

Arduino serial plotter scale limits
  • Plot more than one variable. Print a comma between variables using Serial.print() and use a Serial.println() for the variable at the end of the list. Each plot will have a different color.
  • Plot more than one variable with different labels. The labels will be at the top, in colors matching the relevant lines. Use Serial.print() for each label. You must use a colon (and no space) after the label:

A more efficient way to do that is to send the labels just once, to set up the plot, and then after that you can just send the data:

Arduino Serial Plotter Scale Model

  • Add a ‘min’ and ‘max’ line so that you can stop the plotter from auto scaling (Thanks to Stephen in the comments for this):
  • Or if you have multiple variables to plot, and want to give them their own space:

Arduino Serial Plotter Scale Free

Of course, now the numbers on the y-axis don’t mean much, but you can still see the waveforms.