Serial print commands for debugging

[SouthernAtHeart]

I put a few Serial.println() commands in my code in case I have issues and need to see some data from variables, etc. But in the normal operation of my projects, the Atmega chip isn't connected to a laptop so the serial port isn't used. Do these serial command still execute or slow down the operation of the code?

[marco_c]

Yes they do.

There are lots of ways to have 'debug' and 'not debug' code. Here's one: https://arduinoplusplus.wordpress.com/2017/05/01/simple-debugging-for-arduino-sketches/

[SouthernAtHeart]

That look like a very clean solution!

[GrandPete]

I used to define a "debug_byte" the same way.
But I used it differently like:

#define DEBUG_byte 1
...
if (DEBUG_byte) {Serial.print("setup on-going");

so I need that code each time I need a print, anywhere in my sketch!
so I will now use the hint you provide!