#define pulseLength 50  // Set the length of a pulse
#define numOfPins 8     // Set the number of pins the microcontroller got

int stepsLeft[numOfPins];            //Array to store how many times it should flash the pin
int stepDelay[numOfPins];            //Array to store how long a delay there should be between the pin state changing
unsigned long lastStep[numOfPins];   //Array to store when the pin was changed last

void cyclePins()
{
    unsigned long now = millis();
    for (int i = 0; i <= numOfPins; i++) // Run through the arrays to see if any pin should be changed
    {
        if (stepsLeft[i] > 0) // Do we have to do any steps on this pin?
        {
            if (now - lastStep[i] >= stepDelay[i]) // Calculate if we are at, or passed the set delay time between pulses
            {
                lastStep[i] = now; // Set when we set the pin HIGH, so we can calculate when to set it LOW again
                digitalWrite(i, HIGH); // Set pin to HIGH
            }

            if (now - lastStep[i] >= pulseLength) // Check if pin has been HIGH long enough
            {
                digitalWrite(i, LOW); // Set pin to LOW
                stepsLeft[i]--; // Remove one step
            }
        }
    }
}