#define BITS 10
#define LED_BUILTIN 2
void setup() {
  Serial.begin(115200);
  pinMode(LED_BUILTIN, OUTPUT);
  analogSetAttenuation(ADC_11db);
  analogSetWidth(BITS);
  ledcSetup(0,5000,BITS);
  ledcAttachPin(LED_BUILTIN,0);
}

void loop() {
  int val=analogRead(A4);
  ledcWrite(0,val);
}