Turning on the LED after a while.

For simplicity, you can replace your button with 'push on-off' or add an another 'tact switch' for the same. This will make your code routine much easier.

Remember things that can't be reached with just CODE, can be easily done out with a little tweak in HARDWARE.

Do you mean that I need to add another button? Then how to write this in code?

Through a simple push On-Off button, the Arduino can read the State-change detection, hence the timing sequence can be allocated to desired state.

Through a simple push On-Off button, the Arduino can read the State-change detection, hence the timing sequence can be allocated to desired state.

And if you try like this? Only produces an error: a function-definition is not allowed here before '{' token

int G_LedPin = 13;             
int ButPin = 10;               
int flag = 0;                
int regim = 0;                 

void setup()
{   
  pinMode(G_LedPin, OUTPUT);      
}  

void loop()
{
  if(digitalRead(ButPin) == HIGH && flag == 0)      
    {                                              
      regim ++;
      flag = 1;
      
      if(regim > 1) 
        {            
          regim = 0;
        }
    }
  
  if(digitalRead(ButPin) == LOW && flag == 1)
    {
      flag = 0;
    }  
    
// ======= Perform the task when choosing a mode =======
// REGIM 0: OFF
  if(regim == 0)
    {
      digitalWrite(G_LedPin, LOW);     
    }
    
// REGIM 1: G
  if(regim == 1)
    {
      digitalWrite(G_LedPin, HIGH);    
    }
    void loop() {
digitalWrite(G_LedPin, HIGH); 
delay(10000); 
digitalWrite(G_LedPin, LOW); 
delay(300000);
}   
}

Hi Sofiia,

There are two 'void loop', one needs removing.

You can delete lines 41-46 (that part looks like a test program to blink an LED).

Or you can write before line 41:

#ifdef my_test

and after line 46:

#endif

You can wrap any area of code you don't want to run like that.

(or use // on each line).

Don't use void loop() func. twice as suggested by Shabaz, and the token error is usually due to wrong closure of {\}. Define the blink sequence under (regim==1) while maintaining the 'flag' logic. Hence, avoiding another loop function.

While, you can possibly define another functional loop in your program. Last tip, (optionally) you can use millis() func. instead of delay() for speeding & defining processes on single-core Arduino.

So my task was that when the button was pressed, the LED was turned on for 10 seconds, then turned off and after 5 minutes turned on again for 10 seconds. And so on until the button is pressed again. If I remove lines 41-46, as you advise, then my LED will not flash in the desired mode.

I checked all the brackets. Everything should work, but the error is still the same. I didn’t work with the millis function, so it’s easier for me to convert via "delay"

Re-iterate the code 41-46(seq.) in buttonpressed state. Hope this helps.

Treat 'millis' as suggestion, you can use "delay".