Using Cpp in Arduino IDE

Projects Programming
1

Just started learning. I am using Arduino IDE 1.8.19. Mostly for ESP32 simple example projects. Now, I have CPP file that contains a function that returns two specific times of events; like sunrise and sunset time. This project I chose to learn using cpp in Arduino IDE. Could anyone please help me to learn how to call that function with arguments and get the returned values? I have very minimum experience in C++. Thank you

2

Welcome to the forum

Where did you get the .cpp file from and is there a corresponding .h file ?

3

Welcome to the forum.

It is hard for us to give advice when we don't know what you have.
If it is just a small function, then copy the function in your sketch and forget that *.cpp file.
You can rename the *.cpp file to a *.ino file and just call that function.
If you have also a *.h file with that *.cpp file, then don't rename it, but include the *.h file.

[ADDED]
If you have copied the *.cpp file from a library, then you can add that library.
This is a library: https://github.com/buelowp/sunset It can be added with the Arduino IDE, and then you don't have the *.cpp file in your project.

4

Pretty easy stuff... been explained several times over the years; but, it is a bit advanced for beginners to understand.

I discuss and have an example file here:

Just remember to adjust your #include for the .h if necessary.

Good luck,

Ray

5

when invoking a function, the compiler needs to know what arguments there are and what type of value it returns. in a .ino file, the compiler knows this from the "definition" of the function in the .ino.

when invoking a function external to the file, the compiler needs to see a "declaration"

extern int func (char c, float f);

note the semicolon and lack of a function body which are defined in the external file

rather than put the declaration in each file using the function, it can be put in a .h that is #included in the file calling the function and may include additional function declarations and possibly struct, enums, typedefs that may be used in the external .cpp file

6

The 'extern' is superfluous. Works the same with

int func (char c, float f);
7

yes it is, but it emphasizes the purpose for the OP

8

Thanks for your quick response. I got the .cpp and .h from internet.

9

Thank you very much. Thanks for your suggestions. I will read all the responses and follow the suggestions.

10

Thanks for the examples.

11

Thanks gcjr for the information. I will follow the steps

12

Thanks for this option. I will work on this next weekend

13

From where ? Can you give a link ?

14

Please see post##

15

Post number ?

16

Post #3

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