#define STEP_PIN 26
#define DIR_PIN 27
#define BUTTON_PIN 33


int i_FOREWARD_STEP=1600;//正转多少脉冲
int i_REVERSE_STEP=1600;//反转多少脉冲

// setting PWM properties
const uint8_t freq_PWM = 500;//设置频率，控制速度
const uint8_t channel_PWM = 0;//通道号，取值0 ~ 15
const uint8_t resolution_PWM = 8;//PWM分辨率，取值0 ~ 20


void setup() {
  // put your setup code here, to run once:
  Serial.begin(115200);
  Serial.println("Hello, ESP32!");
  pinMode(BUTTON_PIN, INPUT_PULLUP);
  pinMode(DIR_PIN, OUTPUT);
  ledcSetup(channel_PWM, freq_PWM, resolution_PWM); // 设置通道
  ledcAttachPin(STEP_PIN, channel_PWM);  //将 LEDC 通道绑定到指定 IO 口上以实现输出
}

void loop() {
  // put your main code here, to run repeatedly:
  if(digitalRead(BUTTON_PIN)==LOW){
    delay(300);
    if (digitalRead(BUTTON_PIN)==LOW){
      digitalWrite(DIR_PIN, HIGH);//正转
      // 1/频率*1000=毫秒
      float ms=1.0/freq_PWM*1000.0*i_FOREWARD_STEP;
      Serial.printf("%f",ms);
      ledcWrite(channel_PWM, 50);

      double intPart;
      double fracPart=modf(ms, &intPart);
      delay(intPart);
      delayMicroseconds(fracPart*1000);

      digitalWrite(DIR_PIN, LOW);//反转
      ms=1.0/freq_PWM*1000.0*i_REVERSE_STEP;

      intPart=0;
      fracPart=modf(ms, &intPart);
      delay(intPart);
      delayMicroseconds(fracPart*1000);

      ledcWrite(channel_PWM, 0);
    }
  }
  delay(10);
}