Need some info about tabs in the Arduino IDE

Projects Programming
1

Hi,

My code in one of my projects was getting a bit too long. So I decided to use multiple tabs.
But it is different then how i used it in the past.

Is it normal that if you make a function in lets say the second tab, and you use that function somwhere in the first tab that it doesn't know where it is decleard?

I get this error:

Arduino:1.8.13 (Windows Store 1.8.42.0) (Windows 10), Board:"Arduino Mega or Mega 2560, ATmega2560 (Mega 2560)"


C:\Users\Isaak\Documents\Arduino\Projects\Arduino base station\AMS_1_V2\AMS_1_V2.ino: In function 'void BlynkOnConnected()':

AMS_1_V2:34:3: error: 'RGB_flash' was not declared in this scope

   RGB_flash('B', flashBrightness, flashTime);

   ^~~~~~~~~

C:\Users\Isaak\Documents\Arduino\Projects\Arduino base station\AMS_1_V2\AMS_1_V2.ino: In function 'void security_run()':

AMS_1_V2:349:5: error: 'RGB_flash' was not declared in this scope

     RGB_flash('R', 255, 2000);

     ^~~~~~~~~

AMS_1_V2:353:5: error: 'RGB_flash' was not declared in this scope

     RGB_flash('R', 50, 500);

     ^~~~~~~~~

exit status 1

'RGB_flash' was not declared in this scope


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"Uitgebreide uitvoer weergeven tijden compilatie"
optie aan in Bestand -> Voorkeuren.

RGB_flash is declared in the second tab, and i used this function in the first tab.

my sketch (not that it is neseceary) is in attachment. (it is out thee 9000 characters range)

Is there a reference for using tabs in the IDE?
Or does anyone know anything about it?
I would love to know more!

Isaak

AMS_1_V2.zip (3.71 KB)

2

From your AMS_2_V2.ino, line 3:

void RGB_flash(char COLOUR = 'R' , byte FLASH_BRIGHTNES = 255, int ON_TIME = 100) {

The Arduino function prototype generation system does not support default parameter values. You'll need to manually add a function prototype for this function before the first reference. Best practices is to specify the default parameter values only in the prototype:

void RGB_flash(char COLOUR = 'R' , byte FLASH_BRIGHTNES = 255, int ON_TIME = 100);

and not in the function definition:

void RGB_flash(char COLOUR, byte FLASH_BRIGHTNES, int ON_TIME) {
3

I am surprised that fixed it... well, I learned something new today!
Thx a lot pert!

4

You're welcome. I'm glad to hear it's working now.

By the way, this is nothing specific to tabs. The same will happen even with a single file sketch like this:

void setup() {
  foo();
}
void loop() {}
void foo(byte x = 42) {}

If you want to understand how tabs work in the Arduino IDE, you can see some more technical documenation here:
https://arduino.github.io/arduino-cli/latest/sketch-build-process/#pre-processing

5

Yeah, in the past I always put my function declarations under my loop, but then that error came...
"error" example:

void test(int a = 2) {
...
}

I thouth they changed something with an update.
because if I decleared it on top of the code it worked just fine!

I'm happy this mistery finaly got solved!

edit: ow, will take a look at that link, looks interesting!
Isaak

6

Is there any beginner's guide on how to use Tabs in sketches? I've searched all the help sources and can't find anything useful. What I have gathered is you can put additional standalone sketches in separate tabs which will run "concatenated" with the main sketch, which I presume means consecutively or concurrently, or what? Anyway when I add a second tab with a standalone sketch I get errors with the Setup and Loop functions, like you can't have more than one Setup or Loop, i.e., in a separate Tab? Confusing....

7

That is incorrect. They are not standalone.

"concatenated" is correct, but not "run".

All that happens is that all the .ino files in the sketch folder (which are shown as tabs in the Arduino IDE are combined into a single text file, then that file is compiled.

That's correct. Because they are not "standalone" sketches.

Let me give you an example sketch. The folder structure looks like this:

MySketch
|_ AnotherTab.ino
|_ MySketch.ino

If you open this sketch in the Arduino IDE, you will see two tabs: "MySketch", and "AnotherTab" (file extensions of .ino files are not shown in sketch tabs).

The contents of AnotherTab.ino:

void loop() {
}

The contents of MySketch.ino

void setup() {
}

This sketch's program is exactly identical to this:

void setup() {
}
void loop() {
}

This is what is meant by "concatenated'. The text of the two files are simply added together into one text file.

So the only benefit of having multiple .ino files in a sketch is that it is convenient to split large programs into multiple files so you can quickly navigate to the part of the code you're looking for instead of having to scroll through thousands of lines of code in one single huge file. That's it. There is no magic to multiple .ino files.

8

Oh ok, thanks for the quick reply and the info. Makes sense. So tabs aren't as functional as I hoped but can be useful.

9

You're welcome. I think tabs are a very useful feature of the Arduino IDE.

There is one other aspect of tabs I didn't mention above because I thought it might confuse the discussion. My previous reply only talked about having multiple .ino files in a sketch. However, you can put other types of code files into a sketch, and these will also be shown as tabs:

  • .h - header files, usually used for declarations
  • .cpp - compiled as C++ programming language
  • .c - compiled as C programming language
  • .S - compiled as assembly programming language

These files are not concatenated to your .ino files. They are simply passed to the compiler as-is, without any modification at all. They are not standalone programs though. They still become part of the same program as your .ino files, just not part of the same text file. It's essentially just like an Arduino library, only only accessible from the sketch they are in and displayed for editing in the Arduino IDE.

This is useful in the case where you want to use pure C++/C/assembly. Even though the Arduino programming language is a superset of C++, meaning that any valid C++ is valid Arduino language, and C++ is for the most part a superset of C, and you can do inline assembly language in any of those languages, some people don't want the minor additional convenience features of the Arduino programming language. Using non-.ino files in the sketch allows them to avoid those features.

I personally haven't found the need for this (though I have done a little bit of tinkering around with pure assembly in sketches solely for the sake of learning about it), but I think it's really cool that the Arduino development software has this flexibility.

11

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