Flickering LED's

Hello, using Arduino since a short time only, so still a newbie ... I would like to simulate a server network station with flickering LEDs to simulate internet traffic, up to 6 of them. I have seen that already but would like to know if there is a code ready to use ? And any more info would be welcome. Thank you very much in advance for your help !

Try this:

Find the "several things at once" example here: https://forum.arduino.cc/index.php?topic=223286.0

Create a new int variable called RandomNumber and then add the following to the main Loop() code:

//top of loop

and then... just before every instance of interval or duration add this command... and then add RandomNumber to the line that determines if the correct amount of time has passed.

RandomNumber  = random(2000);   //or so

//Added to --> 
// if (currentMillis - previousLed_B_Millis >= led_B_Interval+RandomNumber) {

So how far that gets you toward your goal.

Wow, thanks for that very helping quick reply !