/*

https://forum.arduino.cc/t/press-button-and-have-led1-come-on-after-5s-delay-and-led2-simply-turn-on/1261609

*/



unsigned long lastPress = 0;      
unsigned long intervalDebounce = 50; 
byte lastBtn = 1; //start high with input pullup

unsigned long lastWait;
unsigned long intervalWait1 = 1000; // 1s delay
unsigned long intervalWait2 = 500; // .5s delay
unsigned long intervalWait3 = 750; // .75s delay


#define BTN_PIN 3 //Push button on D3
#define LED1_PIN 6 //LED 1
#define LED2_PIN 5 //LED 2
#define POT_PIN A5 //the pots..

int LED1_state = 0;
int LED2_state = 0;
//-----------------------------------------------------------------------
int state = 0;                      //integer to hold current state
int old = 0;                        //integer to hold last state
int buttonPoll = 0;                 //integer to hold button state
//------------------------------------------------------------------------

void setup() {
  Serial.begin(115200);
  pinMode(BTN_PIN, INPUT_PULLUP); //button as input activate internal pull up
  pinMode(LED1_PIN, OUTPUT);
  pinMode(LED2_PIN, OUTPUT);

}
//----------------------------------------------------------------------------------
void loop() {
//potentiometer code

//button code
  unsigned long now = millis();

  if (now - lastPress >= intervalDebounce) {
    byte b = digitalRead(BTN_PIN);
    if (b != lastBtn) {
      lastBtn = b;
      lastPress = now;//start debounce
      if (b) {
        //button press and released..
        lastWait = now;
        state++;
        if (state > 3) state = 1;
        Serial.print("Button Press state: ");
        Serial.println(state);
      }
    }
  }

      // potentiometer code; tutorial: https://www.youtube.com/watch?v=Wa8CjGsOFzY&t=2s 
        static int lastSensorVal = 0;
        static int brightness = 0;
        int sensorValue = analogRead(POT_PIN);
        if (lastSensorVal != sensorValue){
          lastSensorVal = sensorValue;
        brightness = map(sensorValue, 0, 1023, 0, 255);
        float voltage = sensorValue * (5.0 / 1023.0);
        //int brightness = sensorValue / 4;
        analogWrite(11, brightness);
        analogWrite(5, brightness);
        analogWrite(6, brightness);
        Serial.println(voltage);
        Serial.print("Voltage: ");
        }

//switch states
  switch (state) {
    case 1:  ////LED1 turns on after .5s delay, and LED2 simply turns on
      if (now - lastWait >= intervalWait1) {
        analogWrite(LED1_PIN, brightness); // on after 1s delay
      } else analogWrite(LED1_PIN, LOW);

      if (now - lastWait >= intervalWait3) {
        analogWrite(LED2_PIN, brightness); // on after .75s delay
      } else analogWrite(LED2_PIN, LOW);   

      break;

    case 2: ////LED1 turns on afer .5s, and LED2 turns on after a 1s delay
      if (now - lastWait >= intervalWait3) {
        analogWrite(LED1_PIN, brightness); // on after .75s delay
      } else analogWrite(LED1_PIN, LOW);

      if (now - lastWait >= intervalWait1) {
        analogWrite(LED2_PIN, brightness); // on after 1s delay
      } else analogWrite(LED2_PIN, LOW);
      break;

    case 3: //// both LED1 and LED2 turn on with .5s delay
      if (now - lastWait >= intervalWait2) {
        analogWrite(LED1_PIN, brightness); // on after .5s delay
      } else analogWrite(LED1_PIN, LOW);

      if (now - lastWait >= intervalWait2) {
        analogWrite(LED2_PIN, brightness);
      } else analogWrite(LED2_PIN, LOW);
      break;


    default: //// both LED1 and LED2 simply turn on without delay
    
       if (now - lastWait >= intervalWait1) {
        analogWrite(LED1_PIN, brightness); // on after 1s delay
      } else analogWrite(LED1_PIN, LOW);

      if (now - lastWait >= intervalWait1) {
        analogWrite(LED2_PIN, brightness); // on after 1s delay
      } else analogWrite(LED2_PIN, LOW);
      break;

  }
}