Where is "Arduino.h"?

I’ve been looking and looking on my iMac but cannot find where the file Arduino.h is. How does the ide find this file when I include it in my sketch but the operating system can’t? Am I crazy?

It's in the folder where the IDE is installed. It's pretty deep in the folder structure.

'Finder' on my mac cannot find it nor a bunch of directories mentioned in Arduino.cc like /hardware/cores. Are these things in 'hidden' folders, packages, other mystical and magical places? What does it mean that a file "is in the IDE"? Appreciate being pointed in the right direction.

Hang on, I gotta switch computers. I don't have Arduino on this one.

OK, on my system (Ubuntu 16.04 with arduino 1.6.9) it at:


With arduino IDE is installed in that arduino-1.6.9 folder. Where that top arduino folder is on your system will be different, but from there on down it should be the same.

OMG!!! It is deep in the Arduino.app package! When I open it in Finder low and behold a whole universe of files becomes visible. Man. Who would have known. Doesn't anyone else use MacOS???
Thanks for your attention at any rate.

Where is "Arduino.h"?

It may be easier to browse / view through Github...


Doesn't anyone else use MacOS???

Most of us are smarter than that... :slight_smile:

On a serious note, Apple is the antithesis of open source, and this is an open source community. Most of us like to be able to customize our stuff however we want.

The only advantage to Apple that I have been able to come up with is that it convinces other hipsters that you are cool.

The only advantage to Apple...

Swift. All the features. None of the crazy syntax.

Yeah, that and that stupid feeling you get when you show up to do a presentation and nobody has one of those overpriced adapters to connect it to a projector that you need because Apple just can't stand making something that follows any sort of common standard. So you have to try to copy it to another computer and then it doesn't look right because Apple has their own standard for that.

To me, having an Apple is like buying a car that can only function in the carpool lane. As long as that's where you're going you're fine. But as soon as you need to play with the rest of the world you're screwed.

'Finder' on my mac cannot find it

Finder doesn't normally look inside of Mac Applications, which are actually directories that contain a bunch of stuff (as you found out.) The assumption is that users don't/shouldn't care about the internals of an application. Which somewhat falls apart when something like Arduino includes a whole directory structure with multiple sub-applications the size of avr-gcc and etc.

You get used to it. It's easier if you're in a bash window of some kind and use the unix commands.

Man. Who would have known.

Every that understands how the Mac installs apps.

Wow, I kicked up a storm. Thanks to those who were helpful. Those who weren't well guess you get you jollies anyway. Yes, it is possible to use unix commands from terminal, and guess that is what the open source people do??? Anyway, now I know and feel much better about my Mac.