const int ledPin = 2;   // LED引脚
const int channel = 0;  // 通道号
const int freq = 5000;  // 频率
const int bitNum = 8;   // 占空比的分辨率
 
void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(ledPin, OUTPUT);
  ledcSetup(channel, freq, bitNum);
  ledcAttachPin(ledPin, channel);
  ledcWrite(channel,  60);
  delay(1000);
  ledcWrite(channel, 255);
}

void loop() {
  // put your main code here, to run repeatedly:
  
}