int x,y=0;

const int freq = 5000;
const int ledChannel = 0;
const int resolution = 8;

void setup() {
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(12, OUTPUT);
  pinMode(26, OUTPUT);
  pinMode(25, INPUT_PULLUP);

  // konfiguracia LED PWM 
  ledcSetup(ledChannel, freq, resolution); //kanal 0, frekv 5000Hz 8bit rozl
  
  // pripojenie GPIO k kanalu
  ledcAttachPin(12, ledChannel);  //pin 12, kanal 0

}

void loop() {
  if(digitalRead(25)==LOW)
   digitalWrite(26,HIGH);
  else digitalWrite(26,LOW);

  x=analogRead(34); //GPIO 34 (Analog ADC1_CH6) 
  Serial.println(x);
  y=map(x,0,4095,0,255);  //12 bit ADC
  ledcWrite(ledChannel, y);
  delay(10); 
}