#define ledPin 22
#define buttonPin 18

int timer_delay = 50;
unsigned long current = 0;
unsigned long timer;

void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  digitalWrite(ledPin, 0);

  pinMode(ledPin, OUTPUT);        // Thiết lập chân LED là đầu ra
  pinMode(buttonPin, INPUT_PULLUP);
}
bool button_status = digitalRead(buttonPin); 
void loop() {

    timer = millis();
    if(timer - current > timer_delay){
      current = millis();
      update_system();
      led_pwm();
    
    //printf("nut nhan %d \n", digitalRead(buttonPin));
    }
  // put your main code here, to run repeatedly:
}
uint16_t brightness = 0;
void led_pwm(){
  if (!button_status){
    brightness += 20;
    if(brightness >= 255){
      brightness = 0;
    }
  }
}
void update_system(){
  button_status = digitalRead(buttonPin);
  analogWrite(ledPin, brightness);
  printf("brightness: %d \n", brightness);
}