Arduino Project (TRAFFIC LIGHTS) *need ideas* - debugging

Question

This is the code I have so far and I need help making the button which is on pin2 of the Arduino have an interrupt where if the lights can cycle on there own and if the button is pressed then it must kick on the yellow LED for 3sec and give the red LED for 10sec for the pedestrian to walk across. The cycle I have set but I need the pushbutton to work and im having difficulties making this work, any suggestions?
CODE
int red = 10;
int yellow = 9;
int green = 8;
int button = 2; // switch is on pin 2
void setup(){
pinMode(red, OUTPUT);
pinMode(yellow, OUTPUT);
pinMode(green, OUTPUT);
pinMode(button, INPUT);
digitalWrite(green, HIGH);
}
void loop() {
if (digitalRead(button) == HIGH){
delay(15); // software debounce
if (digitalRead(button) == HIGH) {
// if the switch is LOW change the lights
changeLights();
delay(1000); // wait for 1 second
}
}
}
void changeLights(){
// RED ON for 5 sec
digitalWrite(red, HIGH);
digitalWrite(yellow, LOW);
digitalWrite(green, LOW);
delay(5000);
// GREEN ON for 5 sec
digitalWrite(red, LOW);
digitalWrite(yellow, LOW);
digitalWrite(green, HIGH);
delay(5000);
// YELOOW ON for 3 sec
digitalWrite(red, LOW);
digitalWrite(yellow, HIGH);
digitalWrite(green, LOW);
delay(3000);
}

Answer 1

This is Arduinos example code for external interrupts:
const byte ledPin = 13;
const byte interruptPin = 2;
volatile byte state = LOW;
void setup() {
pinMode(ledPin, OUTPUT);
pinMode(interruptPin, INPUT_PULLUP);
attachInterrupt(digitalPinToInterrupt(interruptPin), blink, CHANGE);
}
void loop() {
digitalWrite(ledPin, state);
}
void blink() {
state = !state;
}
If the state of pinput pin interruptPin changes the microcontroller will service that interrupt calling blink. then it jumps back to into the application where it was interrupted.
So attach an interrupt service routine to your button pin and store in a variable the information that you should start the yellow red phase at the next chance.
as the yellow red phase usually cannot be interrupted you can use blocking code like delay to time it if your program is not controlling anything elss in the meantime.