How to pause a void in C++ Arduino Uno - c++

Question

My question is very simple but I'm stuck on it for a while now.
I need to make a script that when pushed on a button loop a() is put on pause. And when you press it again it should go from where it ended. But I can't figure out a way to do it.
I hope someone can help me.
This is my code:
int Aan = 1;
int Uit = 0;
int analogPin = A3;
int LED1 = 13;
int LED2 = 12;
int LED3 = 11;
int LED4 = 10;
int val;
bool r = false;
void setup() {
pinMode(analogPin, INPUT_PULLUP);
pinMode(LED1, OUTPUT);
pinMode(LED2, OUTPUT);
pinMode(LED3, OUTPUT);
pinMode(LED4, OUTPUT);
digitalWrite(LED1, Aan);
digitalWrite(LED2, Aan);
digitalWrite(LED3, Aan);
digitalWrite(LED4, Aan);
}
void loop() {
val = digitalRead(analogPin);
if (val == LOW)
{
if (r == true)
{
r = false;
}
if (r == false)
{
r = true;
}
}
if (r == true)
{
a();
}
}
void a() {
for (int i = 10; i <= 13; i++)
{
pinMode(i, OUTPUT);
digitalWrite(i, Uit);
delay(100);
digitalWrite(i, Aan);
}
for (int i = 13; i >= 10; i--)
{
pinMode(i, OUTPUT);
digitalWrite(i, Uit);
delay(100);
digitalWrite(i, Aan);
}
}
Just to explain whats happening.. Void a() makes 4 different leds light up and go out. The pattern thats used is Knight Rider (If you don't know the tv show just google the car of him)

Answer 1

I will assume you want the "Knight Rider" pattern to constantly run.
I've made a couple of changes. First, I added a function to run the led sequence one way. Second, I added a while loop that will always run once, and will continue to run while the button is pushed.
bool paused = false;
int buttonState = HIGH;
void loop() {
a();
}
// This only works if leds ports are consecutive
void runSequence(int ledStart, int ledEnd)
{
int direction = ledStart < ledEnd ? 1 : -1;
for (int i = ledStart; i != ledEnd + direction; i += direction) {
digitalWrite(i, Uit);
do {
delay(100);
} while (LOW == digitalRead(analogPin)); // Check button state
digitalWrite(i, Aan);
}
}
void a() {
runSequence(LED4, LED1);
runSequence(LED1, LED4);
}
EDIT Changes based on comment
bool paused = false;
int buttonState = HIGH;
int currentLED = LED1;
int currentDirection = -1;
void loop() {
checkButton();
if (!paused) {
// Flash the led
digitalWrite(currentLED, Uit);
delay(100);
digitalWrite(currentLED, Aan);
// Change direction?
if (LED1 == currentLED || LED4 == currentLED) {
currentDirection *= -1;
}
// Setup for next iteration
currentLED += currentDirection;
}
}
void checkButton() {
int state = digitalRead(analogPin);
// Check if button state has changed
if (state != buttonState) {
buttonState = state;
// Change paused state when button is released
if (state == HIGH) {
paused = !paused;
}
}
}

Answer 2

Inside your a() function put another while loop which becomes false when the button is Up.
Like:
while(digitalRead(analogPin) == LOW)
{
}
As long as the button is pressed down the loop will continue. When you release the button the program will exit the loop and continue execution of your code.