I'm new to Arduino Ide and for the forum so dont know the place is correct for this question? Help me out if not.
I have tried some of the example where all the syntax is new to me im wondering if i can fetch the complete C code from the ide?
Complete means everything lke main all the functions.
I'm using MPLAB IDE from the Microchip from about 6 years so in there u have to do everything from scratch now that idea is fitted on my mind.
The reason to get full code is i want to learn in deep from taking some pre-written example.
The standard Arduino API is in the Arduino core library files. Note that the location of the active core library can change depending on which board you have selected from the Tools > Board menu.
The easiest way to find the core library location is as follows:
Select a board from the hardware package from the Tools > Board menu
File > Examples > SPI > BarometricPressureSensor
Sketch > Show Sketch Folder
Move up folder levels until you reach the one that contains boards.txt
The core library will be under the cores subfolder
You can find the paths to the various library folders by doing this:
File > Preferences > Show verbose output during: > compilation (check) > OK
Sketch > Verify/compile
After the compilation finishes scroll the black console window at the bottom of the Arduino IDE window up. You will see all the commands the Arduino IDE generated for the compilation process, which will include the paths.
You can also use the example sketch folder trick to easily find the location of any library that has an example sketch. As with the core, the active version of the library may depend on the board selection. You might have multiple versions of a library installed so it's important to make sure you're looking at the one that's actually being compiled for your board.
You should know that it's possible to write as low-level "from scratch" code as you like in the Arduino IDE. The Arduino platform does like to offer a more high-level, beginner friendly option but it's not absolutely forced on you.
For example, the IDE will automatically generate function prototypes in .ino files for you but if you don't want that you can either just add the prototypes yourself or put your code in files with other supported extensions (.cpp, .h, .c, .S, etc.), which the Arduino IDE doesn't do any special preprocessing on.
I agree that it would be a very useful feature to be able to view the external source files. Arduino users tend to treat libraries and the hardware package files as black boxes but if they were easier to access then they could easily take a peek under the hood and find it's just more code similar to what they're already writing in their sketches. I've learned a lot from digging into the source code. I believe that if someone were to submit a pull request to the Arduino IDE adding this feature without harming the user experience (maybe a right click menu item would be better) the Arduino developers would welcome it. I just don't think it's their top priority to implement the feature themselves since the average Arduino user is not clamoring for it.
LED_BUILTIN is defined in the variants/{variant name}/pins_arduino.h under the active hardware package folder I showed you how to find in my last reply. {variant name} is defined by the build.variant property of the currently selected board in boards.txt. You'll note there is also a build.core property defined there, which determines the subfolder of the cores folder that is used for the selected board. I didn't mention that before because most hardware packages only use a single core library but the Arduino IDE does provide the ability for multiple core libraries if a package author needs it.
