Using Arduino Libraries

Overview

Teaching: 20 min
Exercises: 10 min

Questions

• How can Arduino programming be extended?

Objectives

• Don’t re-invent the wheel.

The Arduino programming language provides a lot of basic, low-level functionality, but there are many libraries that can provide higher-level functions that can simplify interacting with specialized hardware or information.

It’s feasible to search for libraries using arduino-cli directly

$ arduino-cli lib search [keyword]

But you can also browse the libraries to more readily see what’s available.

When you’ve identified a library you want to use, you can install it from the command line:

$ arduino-cli lib install [name_of_library]

When programming, you reference a library you want to use with an “#include” statement in your code, and then use the defined elements it provides. In this example, we’re using the TimedBlink library, which keeps track of when a pin should be turned on and off.

// include the library
#include <TimedBlink.h>
int led=6;

TimedBlink monitor(led);

void setup() {
  pinMode(led, OUTPUT);
  // Configure the function with times to stay on and off
  monitor.blink(500,500);
}

void loop() {
  // call frequently to blink at scheduled times.
  monitor.blink();
}

If you try to compile without installing the library, compilation will fail. Install the library and compile again.

Question

Why might this function be useful? How you imagine the function is operationalized? Are there any limitations to this approach?

Finally, under some circumstances, you might want to create a library of your own.

Key Points

• Libraries can provide additional functionality, especially for hardware, but also for functionality.