/** #include <SD.h>
#include <SPI.h>

File myFile;

#define An 9
#define Ap 8
#define Bp 7
#define Bn 6
#define sd 2

enum MotorDirection { CW, CCW };
MotorDirection direction = CW;
enum MotorType { GEARED, NON_GEARED };
MotorType type = GEARED;
enum MotorUse { DEG, RAD, LEAD_SCREW, BELT_GEAR };
MotorUse mode = DEG;

int k;
int choice;
int *m;
int size;
int starts;
int motorsteps;

float number;
float angleDifference;
float angle = 0;
float desiredangle;
float radian;
float pitch;
float lead;
float distance;
float circularpitch;
float radius;
float theta;
float stepangle;
float stepresolution;
float gearratio;

bool sdInitialized = false;
bool fileOpened = false;

int iterations = 1;
int currentIteration = 0;

void setup() {
  Serial.begin(9600);
  pinMode(An, OUTPUT);
  pinMode(Ap, OUTPUT);
  pinMode(Bp, OUTPUT);
  pinMode(Bn, OUTPUT);
  pinMode(sd, OUTPUT);
  initializeSDCard();
}

void loop() {
  if (sdInitialized && !fileOpened && currentIteration < iterations) {
    openFile();
  } else if (fileOpened) {
    if (!readNumbers()) {
      closeFile();
      direction = CW;
      fileOpened = false;
      currentIteration++;
    }
  } else {
    Serial.println("All iterations completed.");
    while (true) {
      // Do nothing, loop indefinitely
    }
  }
}

void initializeSDCard() {
  if (!SD.begin(sd)) {
    Serial.println("SD Card initialization failed!");
  } else {
    Serial.println("SD Card initialized successfully!");
    sdInitialized = true;
  }
}

void openFile() {
  if (sdInitialized) {
    if (SD.exists("numbers.txt")) {
      myFile = SD.open("numbers.txt");
      if (myFile) {
        Serial.println("Reading numbers.txt:");
        fileOpened = true;
      } else {
        Serial.println("Error opening numbers.txt");
      }
    } else {
      Serial.println("numbers.txt does not exist.");
    }
  } else {
    Serial.println("SD card not initialized.");
  }
}

bool readNumbers() {
  if (fileOpened && myFile.available()) {
    String line = myFile.readStringUntil('\n');
    line.trim();
    number = line.toFloat();
    Serial.println(number);

    angleDifference = number - angle;
    angle = number;

    if ((direction == CW && angleDifference > 0) || (direction == CCW && angleDifference < 0)) {
      direction = CW;
      Serial.println("CW");
    } else {
      direction = CCW;
      Serial.println("CCW");
    }
    motorRotate();
    return true;
  } else {
    Serial.println("End of file reached.");
    return false;
  }
}

void setmicrostep(int choice, int *&m, int &size) {
  switch (choice) {
    case 1:
      size = 16;
      m = new int[size] {255, 0, 0, 0, 0, 255, 0, 0, 0, 0, 255, 0, 0, 0, 0, 255};
      break;
    case 2:
      size = 32;
      m = new int[size] {255, 0, 0, 0, 127, 127, 0, 0, 0, 255, 0, 0, 0, 127, 127, 0, 0, 255, 0, 0, 0, 0, 255, 0, 0, 127, 0, 0, 0, 0, 255};
      break;
    case 4:
      size = 64;
      m = new int[size] {255, 0, 0, 0, 64, 64, 0, 0, 127, 127, 0, 0, 191, 191, 0, 0, 0, 255, 0, 0, 0, 64, 64, 0, 0, 127, 127, 0, 0, 191, 191, 0, 0, 0, 255, 0, 0, 0, 64, 64, 0, 0, 127, 127, 0, 0, 191, 191, 0, 0, 0, 255, 0, 0, 64, 64, 0, 0, 127, 127, 0, 0, 191, 191, 0, 0};
      break;
    default:
      break;
  }
}

void motorRotate() {
  steps();
  Serial.println(motorsteps);
  setmicrostep(choice, m, size);

  switch (direction) {
    case CW:
      for (int j = 0; j < motorsteps; j++) {
        for (int i = 0; i < size; i += 4) {
          analogWrite(Ap, m[i]);
          analogWrite(Bp, m[i+1]);
          analogWrite(An, m[i+2]);
          analogWrite(Bn, m[i+3]);
          delay(100);
          k++;
          Serial.print(k);
          Serial.print(" a - ");
          Serial.print(m[i]);
          Serial.print(" b - ");
          Serial.print(m[i+1]);
          Serial.print(" c - ");
          Serial.print(m[i+2]);
          Serial.print(" d - ");
          Serial.println(m[i+3]);
          if (k == motorsteps) {
            k = 0;
            delete[] m;
            return;
          }
        }
      }
      break;
    case CCW:
      for (int j = 0; j < motorsteps; j++) {
        for (int i = size - 4; i >= 0; i -= 4) {
          analogWrite(Bn, m[i]);
          analogWrite(An, m[i + 1]);
          analogWrite(Bp, m[i + 2]);
          analogWrite(Ap, m[i + 3]);
          delay(100);
          k++;
          Serial.print(k);
          Serial.print(" a - ");
          Serial.print(m[i+3]);
          Serial.print(" b - ");
          Serial.print(m[i+2]);
          Serial.print(" c - ");
          Serial.print(m[i+1]);
          Serial.print(" d - ");
          Serial.println(m[i]);
          if (k == motorsteps) {
            k = 0;
            delete[] m;
            return;
          }
        }
      }
      break;
    default:
      break;
  }
}

float step(MotorUse mode) {
  switch (mode) {
    case DEG:
      desiredangle = number;
      return desiredangle;
    case RAD:
      radian = number;
      desiredangle = radian * (180.0 / PI);
      return desiredangle;
    case LEAD_SCREW:
      pitch = 2.0;
      starts = 4;
      lead = starts * pitch;
      distance = number;
      desiredangle = (distance * 360.0) / lead;
      return desiredangle;
    case BELT_GEAR:
      circularpitch = 16.0;
      radius = circularpitch / 2.0;
      distance = number;
      theta = distance / radius;
      desiredangle = theta * (180.0 / PI);
      return desiredangle;
    default:
      return 0;
  }
}

int steps() {
  float step(MotorUse mode);
  choice = 1;
  stepangle = 1.8;
  stepresolution = stepangle / choice;

  switch (type) {
    case GEARED:
      gearratio = 2.0;
      motorsteps = (step(mode) * 1.0 / stepresolution) / gearratio;
      return motorsteps;
    case NON_GEARED:
      motorsteps = (step(mode) * 1.0) / stepresolution;
      return motorsteps;
    default:
      break;
  }
}

void closeFile() {
  myFile.close();
  Serial.println("File closed.");
} **/

//i made some changes and i works as expected. now can you recheck it. below is full code: 

#include <SD.h>
#include <SPI.h>

File myFile;

#define An 9
#define Ap 8
#define Bp 7
#define Bn 6
#define sd 2

enum MotorDirection { CW, CCW };
MotorDirection direction = CW;
MotorDirection pins = direction;
MotorDirection dir = pins;
enum MotorType { GEARED, NON_GEARED };
MotorType type = GEARED;
enum MotorUse { DEG, RAD, LEAD_SCREW, BELT_GEAR };
MotorUse mode = DEG;

int i = 0;
int j;
int choice;
int *m;
int size;
int starts;
int motorsteps;

float number;
float num;
float angleDifference;
float angle = 0;
float desiredangle;
float radian;
float pitch;
float lead;
float distance;
float circularpitch;
float radius;
float theta;
float stepangle;
float stepresolution;
float gearratio;

bool sdInitialized = false;
bool fileOpened = false;

int iterations = 1;
int currentIteration = 0;

void setup() {
  Serial.begin(9600);
  pinMode(An, OUTPUT);
  pinMode(Ap, OUTPUT);
  pinMode(Bp, OUTPUT);
  pinMode(Bn, OUTPUT);
  pinMode(sd, OUTPUT);
  initializeSDCard();
}

void loop() {
  if (sdInitialized && !fileOpened && currentIteration < iterations) {
    openFile();
    delay(1000);
  } else if (fileOpened) {
    if (!readNumbers()) {
      closeFile();
      direction = pins;
      fileOpened = false;
      currentIteration++;
    }
    delay(2000);
  } else {
    Serial.println("All iterations completed.");
    while (true) {
      // Do nothing, loop indefinitely
    }
  }
}

void initializeSDCard() {
  if (!SD.begin(sd)) {
    Serial.println("SD Card initialization failed!");
  } else {
    Serial.println("SD Card initialized successfully!");
    sdInitialized = true;
  }
}

void openFile() {
  if (sdInitialized) {
    if (SD.exists("numbers.txt")) {
      myFile = SD.open("numbers.txt");
      if (myFile) {
        Serial.println("Reading numbers.txt:");
        fileOpened = true;
      } else {
        Serial.println("Error opening numbers.txt");
      }
    } else {
      Serial.println("numbers.txt does not exist.");
    }
  } else {
    Serial.println("SD card not initialized.");
  }
}

bool readNumbers() {
  if (fileOpened && myFile.available()) {
    String line = myFile.readStringUntil('\n');
    line.trim();
    number = line.toFloat();
    Serial.println(number);

    angleDifference = number - angle;
    angle = number;

    if ((pins == CW && angleDifference > 0) || (pins == CCW && angleDifference < 0)) {
      pins = CW;
      Serial.println("CW");
    } else {
      pins = CCW;
      Serial.println("CCW");
    }
    motorRotate();
    //delay(500);
    return true;
  } else {
    Serial.println("End of file reached.");
    return false;
  }
}

void setmicrostep(int choice, int *&m, int &size) {
  switch (choice) {
    case 1:
      size = 16;
      m = new int[size] {255, 0, 0, 0, 0, 255, 0, 0, 0, 0, 255, 0, 0, 0, 0, 255};
      break;
    case 2:
      size = 32;
      m = new int[size] {255, 0, 0, 0, 127, 127, 0, 0, 0, 255, 0, 0, 0, 127, 127, 0, 0, 255, 0, 0, 0, 0, 255, 0, 0, 127, 0, 0, 0, 0, 255};
      break;
    case 4:
      size = 64;
      m = new int[size] {255, 0, 0, 0, 64, 64, 0, 0, 127, 127, 0, 0, 191, 191, 0, 0, 0, 255, 0, 0, 0, 64, 64, 0, 0, 127, 127, 0, 0, 191, 191, 0, 0, 0, 255, 0, 0, 0, 64, 64, 0, 0, 127, 127, 0, 0, 191, 191, 0, 0, 0, 255, 0, 0, 64, 64, 0, 0, 127, 127, 0, 0, 191, 191, 0, 0};
      break;
    default:
      break;
  }
}

void motorRotate() {
  steps();
  Serial.println(motorsteps);
  setmicrostep(choice, m, size);
  // Correcting direction issue
  if (pins == CW) {
    if (dir == CCW) {
      i = (i + 8 + size) % size;
    }
    //Serial.println(dir);
    for (j = 0; j < motorsteps; j++) {
      analogWrite(Ap, m[i]);
      analogWrite(Bp, m[(i + 1 + size) % size]);
      analogWrite(An, m[(i + 2 + size) % size]);
      analogWrite(Bn, m[(i + 3 + size) % size]);
      delay(100);
      Serial.print(j);
      Serial.print(" a - "); Serial.print(m[i]);
      Serial.print(" b - "); Serial.print(m[(i + 1 + size) % size]);
      Serial.print(" c - "); Serial.print(m[(i + 2 + size) % size]);
      Serial.print(" d - "); Serial.println(m[(i + 3 + size) % size]);
      //Serial.println(i);
      i = (i + 4 + size) % size;
    }if (i == (size - 1)){
      i = 0;
    }if (j <= motorsteps){
      j = 0;
      dir = pins;
      pins = direction;
      delete[] m;
    } /**
      for (int i = 0; i < size; i += 4) {
        analogWrite(Ap, m[i]);
        analogWrite(Bp, m[i+1]);
        analogWrite(An, m[i+2]);
        analogWrite(Bn, m[i+3]);
        delay(100);
        k++;
        Serial.print(k);
        Serial.print(" a - ");
        Serial.print(m[i]);
        Serial.print(" b - ");
        Serial.print(m[i+1]);
        Serial.print(" c - ");
        Serial.print(m[i+2]);
        Serial.print(" d - ");
        Serial.println(m[i+3]);
        if (k == motorsteps) {
          k = 0;
          pins = direction;
          delete[] m;
          return;
        }
      }
    } **/
  } else {
    if (dir == CW) {
      i = (i - 8 + size) % size;
    }
    //Serial.println(dir);
    for (int j = 0; j < motorsteps; j++) {
      analogWrite(Ap, m[i]);
      analogWrite(Bp, m[(i + 1 + size) % size]);
      analogWrite(An, m[(i + 2 + size) % size]);
      analogWrite(Bn , m[(i + 3 + size) % size]);
      Serial.print(j);
      Serial.print(" a - "); Serial.print(m[i]);
      Serial.print(" b - "); Serial.print(m[(i + 1 + size) % size]);
      Serial.print(" c - "); Serial.print(m[(i + 2 + size) % size]);
      Serial.print(" d - "); Serial.println(m[(i + 3 + size) % size]);
      //Serial.println(i);
      i = (i - 4 + size) % size;
    } if (i == (size - 1)){
      i = 0;
    } if (j <= motorsteps){
      j = 0;
      dir = pins;
      pins = direction;
      delete[] m;
    }
     /**
      for (int i = 0; i < size; i += 4) {
        analogWrite(Bn, m[i]);
        analogWrite(An, m[i + 1]);
        analogWrite(Bp, m[i + 2]);
        analogWrite(Ap, m[i + 3]);
        delay(100);
        k++;
        Serial.print(k);
        Serial.print(" a - ");
        Serial.print(m[i+3]);
        Serial.print(" b - ");
        Serial.print(m[i+2]);
        Serial.print(" c - ");
        Serial.print(m[i+1]);
        Serial.print(" d - ");
        Serial.println(m[i]);
        if (k == motorsteps) {
          k = 0;
          pins = direction;
          delete[] m;
          return;
        }
      } **/
  }
}

/** void motorRotate() {
  steps();
  Serial.println(motorsteps);
  setmicrostep(choice, m, size);

  // Apply the motor steps based on the direction
  if (direction == CW) {
    Serial.println("CW");
    for (int i = 0; i < motorsteps * size; i += 4) {
      analogWrite(Ap, m[i % size]);
      analogWrite(Bp, m[(i + 1) % size]);
      analogWrite(An, m[(i + 2) % size]);
      analogWrite(Bn, m[(i + 3) % size]);
      delay(100);
    }
  } else {
    Serial.println("CCW");
    for (int i = motorsteps * size - 4; i >= 0; i -= 4) {
      analogWrite(Bn, m[(i + 3) % size]);
      analogWrite(An, m[(i + 2) % size]);
      analogWrite(Bp, m[(i + 1) % size]);
      analogWrite(Ap, m[i % size]);
      delay(100);
    }
  }

  delete[] m;
} **/

float step(MotorUse mode) {
  num = abs(angleDifference);
  switch (mode) {
    case DEG:
      desiredangle = num;
      return desiredangle;
    case RAD:
      radian = num;
      desiredangle = radian * (180.0 / PI);
      return desiredangle;
    case LEAD_SCREW:
      pitch = 2.0;
      starts = 4;
      lead = starts * pitch;
      distance = num;
      desiredangle = (distance * 360.0) / lead;
      return desiredangle;
    case BELT_GEAR:
      circularpitch = 16.0;
      radius = circularpitch / 2.0;
      distance = num;
      theta = distance / radius;
      desiredangle = theta * (180.0 / PI);
      return desiredangle;
    default:
      return 0;
  }
}

int steps() {
  float step(MotorUse mode);
  choice = 1;
  stepangle = 1.8;
  stepresolution = stepangle / choice;

  switch (type) {
    case GEARED:
      gearratio = 2.0;
      motorsteps = (step(mode) * 1.0 / stepresolution) / gearratio;
      return motorsteps;
    case NON_GEARED:
      motorsteps = (step(mode) * 1.0) / stepresolution;
      return motorsteps;
    default:
      break;
  }
}

void closeFile() {
  myFile.close();
  Serial.println("File closed.");
}