How to break the loop in an Arduino? - c++

Question

I'm trying to write a simple program in Arduino, blinking of a LED.
Program is as shown below.
#define red1 13
#define amber1 12
#define green1 11
void setup() {
// put your setup code here, to run once:
Serial.begin(9600);
pinMode(red1, OUTPUT);
pinMode(amber1, OUTPUT);
pinMode(green1, OUTPUT);
}
void Delay(int sec) {
for(int i=0;i<sec;i++){
if (Serial.available())
{
Button();
break;
}
delay(1);
}
}
void Light()
{
digitalWrite(red1,HIGH);
Delay(5000);
digitalWrite(red1,LOW);
digitalWrite(amber1,HIGH);
Delay(5000);
digitalWrite(amber1,LOW);
}
void Button()
{
digitalWrite(red1,LOW);
digitalWrite(amber1,LOW);
digitalWrite(green1,HIGH);
delay(1000);
digitalWrite(green1,LOW);
}
void loop()
{
Light();
}
When ever I enter a value in serial monitor Button() function is executed, it should end as soon as function completes due to a break, but this function keeps repeating continuously? How can I fix this such that whenever a serial monitor is interrupted, Button() is executed onetime and then continues with Light().

Answer 1

Try to replace
break;
with
return;
This will terminate the function instantly since you won't be executing other statements after the loop.
You can look at https://www.arduino.cc/reference/en/language/structure/control-structure/return/ for more info about return

Answer 2

As some others have briefly alluded to, you call Button many times due to the fact that you don't clear the serial interface.
Right now what happens is Delay is called, and let's say there's information available on the interface, then you call Button and break as expected, but since you don't clear the interface by reading the available information, you call Button again on the next call to Delay.
To fix this, you need to read the information from the serial interface either in the Button function or in the if statement before calling Button.