Another Debug Question

Projects Programming
1

I would like to use a macro to enable selective turn on/off of certain lines of code that I might insert for debug purposes. One way to accomplish that would be to use a macro to insert a "//" prefix and turn that line of code into a comment.

Unfortunately I don't know how to define a "//" into a macro to accomplish that. The complier apparently assumes that the "//" is a comment for that line of code and not as an element of the #define statement.

Here's an example of what I want:

#define debug_remove1 //
#define debug_remove2 //
#define etc, etc,

in the code:
debug_remove1 price * qty = total_price; Serial.print (total_price);

In another code location:
debug_remove2 a * b = c; Serial.print (c);

So by defining a specific #define statement as "//" or nothing I can activate/deactivate selective lines of code.

Any ideas on how to insert "//" into the macro definition? Or any other way to accomplish selective turn on/off of specific debug statements?

Thank you,
Frank

2

Don't do that, put

#ifdef 
...
#endif

around the debug code.

3

Duh... ya'think? :slight_smile:

Out of curiosity, is their a way to define "//" in a macro? Maybe an escape char? I tried "" but that didn't seem to work.

Thanks
Frank

4

frank2644:
Out of curiosity, is their a way to define "//" in a macro?

No. If you use '//' it is removed because it is a comment. If you try to paste it together from two separate tokens you get an error: "error: pasting "/" and "/" does not give a valid preprocessing token"

#define comment(a,b) a##b
comment(/,/) This is a comment?

Same for #define comment /##/

5

If there are specific functions that you know you will be using for debug purposes (like Serial prints) you can do something like this:

#ifdef DEBUG
  #define DEBUG_PRINTLN(x) Serial.println(x)
#else
  #define DEBUG_PRINTLN(x)
#endif

With your DEBUG symbol defined, something like DEBUG_PRINTLN("Enter temperature unit conversion function") will be expanded to Serial.println("Enter temperature unit conversion function"), but without the DEBUG symbol defined the same line will expand to nothing and disappear.

6

Thanks everyone,

I've read so many debug threads my head is spinning, but I think I have a passable understanding now.

Frank

7

This works for me:

#define DEBUG true              // Set to true for debug output, false for no debug output
#define Serial if(DEBUG)Serial
8

One of the debug techniques I've adopted from another thread. I just added line number to the message. Actually made an include file with the definitions.

definition:
#define debug_print1(...) Serial.print(F(#VA_ARGS" = ")); Serial.print (VA_ARGS);Serial.print(F("--LINE #"));Serial.println(LINE)

in code:
debug_print1(counter);

Deactivate by #define debug_print1(...) //no definition

Add debug_print2(...), print3, etc.

9

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