// https://forum.arduino.cc/t/arduino-table-fan-with-different-speed-levels-make-your-own/1408082

const int fan(11);
const int button(10);
const int led1(9);
const int led2(8);
const int led3(7);
const int led4(6);
const int led5(5);

unsigned long prevPressTime;

bool prevButtonState(1);

int thresh1(50);
int thresh2(500);

int fanState(0);

void setup() {
  // put your setup code here, to run once:
  pinMode(fan, OUTPUT);
  pinMode(button, INPUT_PULLUP);

  pinMode(led1, OUTPUT);
  pinMode(led2, OUTPUT);
  pinMode(led3, OUTPUT);
  pinMode(led4, OUTPUT);
  pinMode(led5, OUTPUT);
}

void loop() {
  // put your main code here, to run repeatedly:
  bool currentButtonState(digitalRead(button));

  if ((currentButtonState == 0) && (prevButtonState == 1)) {
    prevPressTime = millis();
  } else if ((currentButtonState == 1) && (prevButtonState == 0)) {
    unsigned long elapsedTime(millis() - prevPressTime);

    if ((elapsedTime >= thresh1) && (elapsedTime < thresh2)) {
      fanState += 1;

      if (fanState > 5) {
        fanState = 1;
      }
    } else if (elapsedTime >= thresh2) {
      if (fanState > 0) {
        fanState = 0;
      } else {
        fanState = 1;
      }
    }
  }

  prevButtonState = currentButtonState;

  int fanVal(map(fanState, 0, 5, 0, 255));

  analogWrite(fan, fanVal);

  if (fanState == 0) {
    digitalWrite(led1, LOW);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
    digitalWrite(led5, LOW);
  } else if (fanState == 1) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, LOW);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
    digitalWrite(led5, LOW);
  } else if (fanState == 2) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, LOW);
    digitalWrite(led4, LOW);
    digitalWrite(led5, LOW);
  } else if (fanState == 3) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, LOW);
    digitalWrite(led5, LOW);
  } else if (fanState == 4) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, HIGH);
    digitalWrite(led5, LOW);
  } else if (fanState == 5) {
    digitalWrite(led1, HIGH);
    digitalWrite(led2, HIGH);
    digitalWrite(led3, HIGH);
    digitalWrite(led4, HIGH);
    digitalWrite(led5, HIGH);
  }
}