// https://programmersqtcpp.blogspot.com/2022/08/esp32-pwm-pin.html
#define LEDBLUE   21  
#define LEDRED    19  

void setup() {
  Serial.begin(115200);
         
  double result = ledcSetup(0, 875, 11); // ch 0, f 875Hz, res 11-bit
  if (!result) Serial.println("errore");
  Serial.println(result);
  
  ledcAttachPin(LEDRED, 0); // attach LEDRED on ch 0
  ledcAttachPin(LEDBLUE, 0); // attach LEDBLUE on ch 0

  for (uint16_t i=0; i<2048; i++) {
      delay(1);
      ledcWrite(0, i);
      if (i == 2047) Serial.println("Ok");
  }
}

void loop() {
  
  delay(1);
    
}