Library Reference

Posted here for lack a a better place and for being least intrusive, but...

In the 'help', 'reference' selection in my v1.8.9 I obviously can get reference and usage of library routines and functions for most of the standard stuff.

If I add new libraries then where do I find the usage details and formats for the new routines and functions. There must be a standard location but I'll be d****d if I can find them.


For most official Arduino libraries, you'll find documentation here:

Most libraries come with example sketches that demonstrate the use of the library. You'll find these under File > Examples > {library name} after installing the library.

With 3rd party libraries, it will be different from one library to another. You should start by checking the readme shown in the library's repository. If you're downloading the library manually then you'll already know the location of the repository. If you're using the Arduino IDE's Library Manager to install the library then you can click the "More info" link. If the readme doesn't provide documentation or a link to documentation, you might look to see if there is a "Wiki" tab at the top of the library's GitHub repository. Sometimes you'll find some excellent documentation hidden away in the wiki, but not mentioned anywhere else.

Some library authors don't bother to provide documentation. You can always just look at the source code. Sometimes there will even be detailed documentation provided in comments in the source. The .h files contain the declarations of the library functions so this can act as a quick reference for which functions are available, what their return types are, and what parameters they take. For more details on how the function works, find the function definition in the .cpp file.

Thanks for the reply and info.

I had already found some of the info you present here and being new to this I was looking for things I may have missed. The Arduino IDE presents the reference section in a quick and easy way to get the details for the standard stuff. Just making sure there wasn't something similar for the other libs. I'll use your recommended resources as I move along.


The Arduino IDE has a cool feature where you can right click on some code in your sketch and select "Find in Reference" (or Help > Find in Reference). However, this only works for the terms that are in the official reference and have been correctly defined as keywords so the Arduino IDE can recognize them. I'd really like to see Arduino expand that feature so it's possible for 3rd party library authors to provide reference content with their libraries that the Arduino IDE would open via "Find in Reference".

One warning about using "Find in Reference" and the documentation under the Arduino IDE's Help menu: the accessed information is from html files bundled with your Arduino IDE installation. Unfortunately, this documentation is currently years out of date compared to the equivalent documentation found in the reference pages here on Significant improvements have been made to the documentation content since that time. Ideally, the reference content bundled with the Arduino IDE should be updated every time the Arduino IDE is released. The documentation would still end up being a little bit out of date as improvements are made after the release of the Arduino IDE, but it would be a matter of months rather than years.