// Sketch for testing switch between loops for LED patterns v3 (remembers mode state)

unsigned long lastMilli = 0;
int intervalDelay = 500;
byte mode = 1;
unsigned long lastCheck = 0;

int ledPin =  9;      // the number of the LED pin
int pinSwitch = 2;    // pin to button to GND (use internal pullup)

int ledState = LOW;             // ledState used to set the LED

unsigned long M1InitOnTime        = 500;           // milliseconds of on-time
unsigned long M1OnIncrement   = 100;       // increment on time in milliseconds
unsigned long M1OnTimeMax        = 1000 - M1OnIncrement; // Mode 1 max on time before cycling back to start

unsigned long M2InitOnTime         = 1000;      // milliseconds of on-time
unsigned long M2OnIncrement    = 1000;      // increment on time in milliseconds
unsigned long M2OnTimeMax         = 5000 - M2OnIncrement; // Mode 2 max on time before cycling back to start

unsigned long M1OnTimeCurr = M1InitOnTime;   // initialize variable for Mode 1 current On Time incrementing
unsigned long M2OnTimeCurr = M2InitOnTime;   // initialize variable for Mode 2 current On Time incrementing

unsigned long currentMillis;
byte butLst;   // last button state

// -----------------------------------------------------------------------------
void loop ()
{
    currentMillis = millis ();

    byte but = digitalRead(pinSwitch);
    if (butLst != but)  {
        butLst = but;
        delay (20);     // debounce
        if (LOW == but)
            mode = !mode;
    }

    if (mode)
        mode1 ();
    else
        mode2 ();
}

// -----------------------------------------------------------------------------
void mode1 ()
{
    if (currentMillis - lastMilli >= M1OnTimeCurr)  {
        lastMilli = currentMillis; // Remember the time

        if (ledState == HIGH) {
            ledState = LOW;  // Turn it off

            // increment on time up to Max
            if ((M1OnTimeCurr <= M1OnTimeMax))
                M1OnTimeCurr = M1OnTimeCurr + M1OnIncrement;
            else
                M1OnTimeCurr = M1InitOnTime;
        }
        else 
            ledState = HIGH;  // turn it on

        digitalWrite (ledPin, ledState);  // Update the actual LED

        Serial.print ("mode1: ");
        Serial.println (M1OnTimeCurr);
    }
}

// -----------------------------------------------------------------------------
void mode2 ()
{
    if (currentMillis - lastMilli >= M2OnTimeCurr)  {
        lastMilli = currentMillis; // Remember the time

        if (ledState == HIGH) {
            ledState = LOW;  // Turn it off

            // increment on time up to Max
            if ((M2OnTimeCurr <= M2OnTimeMax))
                M2OnTimeCurr = M2OnTimeCurr + M2OnIncrement;
            else
                M2OnTimeCurr = M2InitOnTime;
        }
        else 
            ledState = HIGH;  // turn it on

        digitalWrite (ledPin, ledState);  // Update the actual LED

        Serial.print ("mode2: ");
        Serial.println (M2OnTimeCurr);
    }
}

// -----------------------------------------------------------------------------
void setup ()
{
    pinMode (ledPin, OUTPUT);
    pinMode (pinSwitch, INPUT_PULLUP);
    butLst = digitalRead (pinSwitch);

    Serial.begin (9600);
}