ESP32产生PWM的Arduino程序

const int ledPin = 2;  // PWM生成后实际输出引脚
//设置PWM参数
const int freq = 4000;//PWM频率
const int ledChannel = 0;//信号生成GPIO
const int resolution = 12;//12位分辨率，by Jason. 可设置1~14bits
void setup(){
  //PWM参数设置
  ledcSetup(ledChannel, freq, resolution);
  //将生成信号通道绑定到输出通道上
  ledcAttachPin(ledPin, ledChannel);
}
void loop(){
  //逐渐变亮，12位分辨率因而到4096
  for(int dutyCycle = 0; dutyCycle <= 123;dutyCycle++){   
    // changing the LED brightness withPWM
    ledcWrite(ledChannel, dutyCycle);
    delay(20);
  }
  //逐渐变暗
  for(int dutyCycle = 123; dutyCycle >= 0;dutyCycle--){
    // changing the LED brightness with PWM
    ledcWrite(ledChannel,dutyCycle);   
    delay(20);
  }
}