const int PIN = (6);
const int Button = (2);
bool prevButtonState = 1;
uint32_t prevtime = 0;
const uint32_t DEBOUNCE_DELAY = 100;

void setup() {
  Serial.begin(115200);
  pinMode(2, INPUT_PULLUP);
  pinMode(PIN, OUTPUT);
}

void loop() {
    if (!digitalRead(Button) && prevButtonState) {
      static bool state = false;
      if (state) {
        for (uint8_t i = 0; i<255;i++) {
          analogWrite(PIN, 255-i);
          delay(5);
        }
      } else {
        for (uint8_t i = 0; i<255;i++) {
          analogWrite(PIN, i);
          delay(5);
        }
      }
      state != state;
    }
}