The Arduino Clever Plotter

Any Arduino or Arduino compatible board

Mac OSX

Linux (any flavour)

Windows

Laptop or computer

<html><body><h3>The need for a clever plotter</h3>Arduino can be used as a data acquisition system in scientific application, where you want to store data on files for further processing, and look at plots online. The Arduino IDE's Serial Plotter is quite limited: you have little control of what is going to be shown. With the Arduino Clever Plotter (ACP) you can plot data as usual, but you can control what is shown on the x-axis and the limits of the y-axis. You can assign meaningful names to graphs and choose the best representation. The ACP stores data on files, too. <h3>For the impatient</h3><ol><li>Download the application from <a href="https://github.com/organtin/physics/blob/413ce51619bf7979d301cf324114f2cf2b2cdfd5/Springer/physWArduinoSmartphones/acp.py">here </a></li><li>Upload a sketch on you preferred Arduino board, such that it outputs data as a list of comma separated values </li><li>Run the ACP </li></ol>Below, an example of what you can see when collecting data from an experiment in which you measure the voltage across a capacitor in an RC circuit <figure><iframe src="https://youtu.be/fCVVjacNQgE"></iframe></figure><h3>Preparing your Arduino sketch</h3>The ACP can run similarly to the IDE's Serial Plotter. If you just print out a single value, as <pre>	 Serial.println(mydata) </pre>then the ACP will plot data as a function of the number of loops. If you print more than one value, separated by commas, such as <pre>	 Serial.print(x_data); </pre><pre>	 Serial.print(","); </pre><pre>	 Serial.print(y_data); </pre><pre>	 Serial.print(","); </pre><pre>	 Serial.println(z_data); </pre>then, the ACP will make three graphs on the same plot, as shown below: <figure><img src="https://projects.arduinocontent.cc/2785a07e-393f-46c8-8c42-7e3d0a674f5b.png"/><figcaption>The output of the ACP with three graphs on the same plot</figcaption></figure>Each graph is automatically labelled and a legend appears on the top left corner. The x-axis corresponds to the number of loops. It is worth noting that, if no Arduino is found, the ACP will simulate its presence writing random data on the port. If you want to plot data as a function of another quantity collected during the run, you can declare it as such in the setup() function, writing an XML structure to the serial port as <pre>	 Serial.println("&lt;header&gt;&lt;x&gt;t [$\\mu$s]&lt;/x&gt;&lt;/header&gt;"); </pre>When the ACP detects this string, it interprets the first number found in the comma separated list as the variable to be plotted on the x-axis. The axis is also labelled after the content of the &lt;x&gt; tag. In the example, as "t [𝜇s]" ($\\mu$ is rendered as a 𝜇). You can label the data on the y-axis adding the corresponding labels. For example: <pre>	 Serial.println("&lt;header&gt;&lt;x&gt;t [$\\mu$s]&lt;/x&gt;&lt;y&gt;V_C [V]&lt;/y&gt;&lt;/header&gt;"); </pre>If there are more data to plot in the comma separated list, you just provide a comma separated list of labels in the XML in the &lt;y&gt; tag: <pre>	 Serial.println("&lt;header&gt;&lt;x&gt;t [$\\mu$s]&lt;/x&gt;&lt;y&gt;V_C [V],V_R [V]&lt;/y&gt;&lt;/header&gt;"); </pre>The y-scale is automatically adjusted to make room for the plot. If you want to fix it, just add the lower and/or the upper values, using the &lt;ylim&gt; tag: <pre>	 Serial.println("&lt;header&gt;&lt;x&gt;t [$\\mu$s]&lt;/x&gt;&lt;y&gt;V_C [V]&lt;/y&gt;&lt;ylim&gt;0,None&lt;/ylim&gt;&lt;/header&gt;"); </pre>or <pre>	 Serial.println("&lt;header&gt;&lt;x&gt;t [$\\mu$s]&lt;/x&gt;&lt;y&gt;V_C [V]&lt;/y&gt;&lt;ylim&gt;0,1023&lt;/ylim&gt;&lt;/header&gt;"); </pre>or, again, <pre>	 Serial.println("&lt;header&gt;&lt;x&gt;t [$\\mu$s]&lt;/x&gt;&lt;y&gt;V_C [V]&lt;/y&gt;&lt;ylim&gt;None,10&lt;/ylim&gt;&lt;/header&gt;"); </pre>The ACP automatically store data in a CSV file called acp.csv by default. This way you can analyse data offline, if needed. <h3>Controlling the application</h3>The ACP starts just launching acp.py. No arguments are required. The -h switch provides some help <pre>&gt; python3 acp.py -h </pre>You can choose te port to read data from using the -p switch. The filename where data are stored is, by default, acp.csv, but you can change it with the -f switch. If no Arduino board is found, the ACP will simulate its presence. You can simulate the dispatch of the header with the -s switch. In this case data are labelled as "x (m)", "y (m/s$^2$)" and "z (kg)". To add a simulated x-column, just add a -t switch to the acp.py command. The ACP runs forever, unless you use the switch -n telling how many loops to collect. When the number of rows read from Arduino is equal to this number, the ACP stops and wait for you to close the plot window. The x-axis shows, by default, the last 100 numbers collected. You can change this number with the -r switch. The -m switch let you choose a different maker for data. Just use the format of the matplotlib.pyplot library. For example "-m o-" represents data with small circles connected by a line. The -b switch is used to set the baud rate (default is 9600). ACP becomes verbose if the -v switch is on. <h3>Licensing</h3>The ACP is licensed after the GNU General Public License version 3. For further details run the script with the switch -l. </body></html>

The Arduino Clever Plotter

A flexible plotter for data collected with Arduino