#include <SoftwareSerial.h>
#include <AccelStepper.h>

#define EN 4
#define STEPS_PER_REVOLUTION_IN_START 75
#define STEPS_PER_REVOLUTION_REV_IN_START 500

int stepsPerRevolution = STEPS_PER_REVOLUTION_IN_START;
int stepsPerRevolutionRev = STEPS_PER_REVOLUTION_REV_IN_START;

AccelStepper myStepper (AccelStepper::DRIVER, 9, 8) ;

void setup() {
  Serial.begin(115200); // Initialize the serial port // Initialize the mySerial port
  myStepper.setMaxSpeed (500);
  myStepper.setAcceleration (100000);
  myStepper.setEnablePin(EN);
  //myStepper.setPinsInverted(false, false, false, false, false);
  String dd = "";
  //myStepper.disableOutputs();
  pinMode(EN, OUTPUT);
}

void loop() {
  String state = Serial.readStringUntil('\n');
  if (state.length() > 0) {
  if (state.length() == 3) {
    stepsPerRevolution = state.toInt();
    Serial.println(stepsPerRevolution);
  }
    if (state == "1") {
      //Serial.println(dd);
      myStepper.move(stepsPerRevolutionRev);
      int tmpSteps = myStepper.currentPosition() + stepsPerRevolution;
      while (myStepper.currentPosition() != tmpSteps) {
        myStepper.run();
      }
      myStepper.stop(); // Stop as fast as possible: sets new target
      myStepper.runToPosition(); // Now stopped after quickstop
      tmpSteps = myStepper.currentPosition() - stepsPerRevolutionRev;
      myStepper.move(-stepsPerRevolutionRev); // Now go backwards
      while (myStepper.currentPosition() != tmpSteps) {
        myStepper.run();
      }
      myStepper.stop(); // Stop as fast as possible: sets new target
      myStepper.runToPosition();
    }
  }
  digitalWrite(EN, HIGH);
  myStepper.disableOutputs();
}