How do I debug and resolve Arduino code compilation errors?

[genieeee]

I'm currently working on an Arduino project and I'm facing some errors during the compilation of my code. I'm not sure how to debug these errors and resolve them. Could someone please provide me with guidance on how to effectively debug Arduino code and identify the root cause of these compilation errors? Additionally, any tips or best practices for resolving common Arduino code errors would be highly appreciated. Thank you in advance for your assistance!

moderator edit: spam removed

[paulpaulson]

Hello genieeee

Start with with first error reported by the compiler.

If you are not yet confident in programming, then take small steps and give the programme to the compiler to check. The compiler will be happy about it.

Have a nice day and enjoy coding in C++.

p.s.

https://www.learncpp.com/cpp-tutorial/introduction-to-cpp-development/

[LarryD]

• For syntax errors you need to become familiar with C++.

• Read this discussion
  Gammon Forum : Electronics : Microprocessors : Debugging using SPI/I2C and a second processor

• Read these discussions:

Share tips you have come across

Further to post #459 An oscilloscope can be a valuable tool when tracking down problems in your Arduino projects. We need to trigger the scope at the right time before signal analysis can proceed. Code to produce a pulse of ~63ns can be inserted at an appropriate location in your existing sketch. The scope can then use this pulse to trigger the display. Below are Debugging Macros to control output pins for diagnostics. Also included are some useful Port Manipulation macros that you can u…

Share tips you have come across

A few weeks back I used the following technique to troubleshoot a software issue. Many here have done similar. The following discussion might help new users. • If others can add to this discussion please do so. • New users should also remember, using Serial.print() is still a valid way to troubleshoot many/most problems. You will need to have either a digital oscilloscope or a logic analyzer. Images seen below were made on a 350 MHz Rigol oscilloscope; however, a lower band width digital …

Using the serial monitor for debugging / analysing what is going on inside your code

The most minimalistic sketch to get some words onto the serial monitor is void setup() { // activate serial interface with a baudrate of 115200 Serial.begin(115200); Serial.println( F("Hello World") ); } void loop() { } As setup runs only once per power-on / reset a single line with the coded words "Hello World" apears in the serial monitor [grafik] With each pressing of the reset-button the program starts new sending this single line with Hello World [grafik] Next step is to u…

[xfpd]

@genieeee

provide me with guidance

This will introduce you to compile time errors...

Self Balancing Cube? Is this black magic?!

[StefanL38]

of course you can ask in the forum too.
The Arduino-IDE can be adjusted to write different amounts of compiler-messages into the compiler-log.

Here is a tutorial how to adjust the compiler to write the maximum into the compiler-log and how to post this compiler-log into a posting in a way that makes it easy for other users to crawl through all the text.

If you get a compiler-error provide all details for analysing the error

Hi newcomer, the Arduino-Forum community can be of great help. If the community is able to support you in a way that helps solving your problems depends on detailed information that you should provide. trying to be quick by posting a too short posting is just slowing down finding the solution. Because all that happends is that you are asked for the detailed information and have to provide it anyway. Only difference the answer and the solution comes later The most important thing is to pos…

not all but a lot of errors can be found by searching for ": error:"
as code-section

: error:

in words because each character is important:
a double-point a space the word "error"
if you just search for "error" without the double-point-space you will find a lot of lines in the compiler-log that are not relevant
second is
: fatal error:
double-point space "fatal"

@the community:
there are some traps that are hard to find for newcomers:
example

if ( myfunction(myparameter)   {

missing the second closing parenthesis ")"

if ( myfunction(myparameter)   {
if ( myfunction(myparameter) ) {

often leads to "not declared"-errors because the missing closing parenthesis says to the the compiler take all the following code as parameters of the function instead as their own functions.

Is there somewhere a list with such hard to find syntax-errors?

best regards Stefan

[PaulRB]

@paulpaulson

Start with with first error reported by the compiler.

@genieeee This advice might sound obvious, but there is an important reason for it.

The compiler reads the code from top to bottom. Errors at the top can cause the compiler to believe there are some errors later in the code that are not really there, because if one of those earlier errors got fixed, it's possible some of the later errors would "evaporate". So if you dive in to fixing one of the "errors" in the middle of the code somewhere, it might be a waste of time.

[Juraj]

terminology note: we debug a running code, not the compilation errors. compilation errors are not bugs

[awneil]

@genieeee

I'm facing some errors during the compilation of my code. I'm not sure how to debug these errors and resolve them

As @Juraj said, "debug" is usually used to mean fixing problems in the running code - rather than compiler errors.

There's another very similar thread running now; here's a couple of examples - would be worth reading the whole thread:

Where to find info on how to code

The secret with errors is just to read them literally If they say something is "not defined" - then you need to define it; if they say something is "duplicated" - then you need remove the duplication; etc, ... Now the compiler does assume that you are familiar with the language syntax and terminology. The language used by Arduino is C++ - so any C++ textbooks, tutorials, etc should help with that. As @sterretje a lot of general C++ textbooks, tutorials, etc will be focussed on desktop syste…

Where to find info on how to code

Another Top Tip with errors: Always start with the first-reported error. Very often, one error will lead to other things being wrong - often, lots of other things. Therefore fixing that first error will instantly get rid of all those consequent errors.

As @LarryD said, dealing with compiler errors does require that you are familiar with C++ terminology and syntax

[alto777]

@genieeee

how to… identify the root cause of these compilation errors?

Sometimes the compiler errors are hard to untangle, even starting with the first may be a red herring.

You can use the IDE Autoformat tool. This can be a big help for finding missing or misplaced { braces }.

The IDE will also help you see or find extra parentheses and some things like that.

It is best to develop in steps and not get so far ahead in the code that you are not able to focus your error finding efforts to the code you have been working on.

a7