Description

The macros defined in this package make it easy to properly format data for display by the Arduino Serial Plotter program. It's also not a bad way to display data in the Serial Monitor for many applications.

The Arduino Plotter accepts named values in the following format

foo:43 bar:65 baz:21

The key and value are separated by a ':', and multiple key/value pairs are separated by white space. If you separate the key and value with '/', it conveniently displays the key and value on the top line with the other keys.

Usage

• MONITOR(v) will output the variable v, keyed by the variable name.
• MONITOR2(k, v) allows the key to be specified. It's useful if v isn't a variable name.
• MONITOR_ENDL() will end monitor output.
• MONITOR_RESET() will clear and reinitialize the plotter display.
• DISPLAY(v) and DISPLAY2(k, v) are similar to MONITOR and MONITOR2, except they use '/' as a separator, giving a non-plotted display of the key and value.

Defining the macro NO_MONITOR_OUTPUT removes all monitoring data from the compiled code.

Examples

#include "ArrbotMonitor.h"
#include <math.h>

void setup() {
  Serial.begin(9600);
}

// Uncomment the following line to disable monitor output
// #define NO_MONITOR_OUTPUT

float scale = 10.0;
float x = 0.0;
void loop() {
  x += .01;
  float s = sin(x) * scale;
  float really_long_name = cos(x) * scale;

  DISPLAY(scale);
  MONITOR(s);
  MONITOR2("cos", really_long_name);
  MONITOR_ENDL();
}

Here's a real-life example of a PID loop tuning session.

Notes

Sometimes a variable will appear twice at the top of the Arduino Serial Plotter window. This seems to be a bug in the Plotter.

The DISPLAY logic in the Serial Plotter is not documented. I'm submitting a PR to document this and make it a standardized part of the interface.

MONITOR_RESET() is reserved for future use.

Thanks to coworker Jonah Dahlquist for encouraging me to write this up.