Blank Arduino Sketch Uses 450 Bytes of Program Storage Space and has 9 Bytes of Global Variable?

I went on and try compiling an int main(), while loop in Arduino IDE and get 0 Bytes global variable and lesser program storage usage.

Here is a comparison sketch (a version of Blink) using an int main() while loop style vs the Arduino setup() loop()... in the same Arduino IDE

int main()  while loop:

Arduino setup() loop() style:

I don't know what is in the setup() loop() style that adds too many bytes in the program storage space. it is about double compared to using an int main() while loop.

Another variation of the int main() while loop:

If you use the AVR Studio (I am using version 6) you see that the setup() and loop() functions can be defined to obtain the behaviour of the sketch IDE. Just the fact that you declare these functions mean that you need a main function entry point, a variable to manage the loop() and the two function pointer themselves for setup() and loop(). The concept is that with direct language-to-machine management you can do almost what you want while with Arduino users take advantage of some simplifications but pay this with few more memory usage due the default minimal components that are preset.

As a matter of fact, it is not a low level programming, as you have the setup() and loop() functions and the relative minimal environment defined there. I am almost sure that this does not depends on the compiler itself (but the compiler may change the optimisations for sure in some cases) because with the same compiler a real C++ code written in AVR Studio generates a more compact binary than the same equivalent code with the arduino IDE.

As far as what is my experience, this increased optimisation and reduced size of the binary will occur also using the same architecture of a "sketch" treated more seriously as a C++ source program instead of the pre-cooked version supported by the IDE.

Enrico

Please select option to show all details and run these tests again. When you do you will see what code is added and  can surmise why the differences.

clem

Enrico, could you please try and compile a blink program in the AVR Studio that you mentioned?

I would like to see how many bytes it uses. Your contribution is much appreciated.

Thanks.

Enrico, could you please try and compile a blink program in the AVR Studio that you mentioned?

I would like to see how many bytes it uses. Your contribution is much appreciated.

Thanks.

Orlando, what do you mean as a blink program ?

I'll do asap.

Enrico

Could you try a main approach versus a void setup/loop? I wrote the internals until my browser crashed and nothing recovered.

clem57 Ok, but there is something that I have not clear. Welcome to make a test anyway, but let me explain.

Need to be an empty program? Without loop, you mean a simple main that does not includes the wile(forever) function? Let me know what is the exact need. I can try it tomorrow just because I should reload the AVR Studio VM machine while in this moment I am working on the Raspberry PI.

Enrico

Hi all, I'm new to Arduino and C programming.  I noticed the version of the compiler being used.  Its V1.7.3.  The latest release is V1.6.4  Is it something to do with the version?  Also, is this just to insure that you use as little of the Arduino memory for your programs.  Thanks.

Regards,

Dave M.