New Code

#include "I2Cdev.h"
#include "MPU6050.h"
#include <Wire.h>
#include <SD.h>
int pinCS = 10;
File myFile ;
// FIND MEMORY SPACE ! ! !
///////////////////////////////////   CONFIGURATION   /////////////////////////////
//Change this 3 variables if you want to fine tune the skecth to your needs.
int buffersize = 1000;   //Amount of readings used to average, make it higher to get more precision but sketch will be slower  (default:1000)
int acel_deadzone = 8;   //Acelerometer error allowed, make it lower to get more precision, but sketch may not converge  (default:8)
int giro_deadzone = 1;   //Giro error allowed, make it lower to get more precision, but sketch may not converge  (default:1)

// default I2C address is 0x68
// specific I2C addresses may be passed as a parameter here
// AD0 low = 0x68 (default for InvenSense evaluation board)
// AD0 high = 0x69
//MPU6050 accelgyro;
MPU6050 accelgyro(0x68); // <-- use for AD0 high int cnt = 0; // for counting up to 100 , then reading the SD card.
int cnt=0;
int cnt2 =0; // for counting the number of calibration steps.
int16_t ax, ay, az, gx, gy, gz;

int mean_ax, mean_ay, mean_az, mean_gx, mean_gy, mean_gz, state = 0;
int ax_offset, ay_offset, az_offset, gx_offset, gy_offset, gz_offset;
int ready = 0;

long accelX, accelY, accelZ;
float gForceX, gForceY, gForceZ;

long gyroX, gyroY, gyroZ;
float rotX, rotY, rotZ;

void setup() {

  pinMode(pinCS, OUTPUT);
  Serial.begin(9600);
  if (SD.begin())
  {
    Serial.println("SD card is ready to use.");
  } else
  {
    Serial.println("SD card initialization failed");
    return;
  }


  // join I2C bus (I2Cdev library doesn't do this automatically)
  Wire.begin();

  // start message
  Serial.println("Starting 5 seconds timer to give time for the new program to upload: ");
  delay(5000);
  Serial.println("\nMPU6050 Calibration Sketch");
  delay(2000);
  Serial.println("\nYour MPU6050 should be placed in horizontal position, with package letters facing up. \nDon't touch it until you see a finish message.\n");
  delay(3000);

  // verify connection
  Serial.println(accelgyro.testConnection() ? "MPU6050 connection successful" : "MPU6050 connection failed");
  delay(1000);

  // reset offsets
  accelgyro.setXAccelOffset(0);
  accelgyro.setYAccelOffset(0);
  accelgyro.setZAccelOffset(0);
  accelgyro.setXGyroOffset(0);
  accelgyro.setYGyroOffset(0);
  accelgyro.setZGyroOffset(0);

  setupMPU();

  if (state == 0) {
    Serial.println(F("\nReading sensors for first time..."));
    meansensors();// why is this function called 2 times ? TODO ! ! ! <-----------------------------------------------------------------------------////////////////////////////////
    state++;
    delay(1000);
  }

  if (state == 1) {
    Serial.println(F("\nCalculating offsets..."));
    calibration();
    state++;
    delay(1000);
  }

  if (state == 2) {
    meansensors();
    Serial.println(F("\nFINISHED!"));
    Serial.println(F("Number of calibration steps: \t ")); Serial.print(cnt2);
    Serial.print(F("\nSensor readings with offsets:\t"));
    Serial.print(mean_ax);
    Serial.print("\t");
    Serial.print(mean_ay);
    Serial.print("\t");
    Serial.print(mean_az);
    Serial.print("\t");
    Serial.print(mean_gx);
    Serial.print("\t");
    Serial.print(mean_gy);
    Serial.print("\t");
    Serial.print(mean_gz);
    Serial.print(F("Your offsets:\t"));
    Serial.print(ax_offset);
    Serial.print("\t");
    Serial.print(ay_offset);
    Serial.print("\t");
    Serial.print(az_offset);
    Serial.print("\t");
    Serial.print(gx_offset);
    Serial.print("\t");
    Serial.print(gy_offset);
    Serial.print("\t");
    Serial.println(gz_offset);
    Serial.println(F("\nData is printed as: acelX acelY acelZ giroX giroY giroZ"));
    Serial.println(F("Check that your sensor readings are close to 0 0 16384 0 0 0"));
    Serial.println(F("        ---------------------------------         "));

     myFile = SD.open("test.txt", FILE_WRITE);
    //Serial.println(F("If this value is 0, you've fucked something up :D")); always gives 0 ?
    Serial.print(myFile);
    if (myFile) {
     Serial.println("Yaaay, we are writing to the file :D");
     myFile.print("The offsets are: \n ");
    myFile.print(ax_offset); myFile.print("\t");

    myFile.println(ay_offset); myFile.print("\t");

    myFile.println(az_offset); myFile.print("\t");


    myFile.close(); // close the file
  }
  else {
    Serial.println(F("error opening test.txt"));
  }
  delay(1000);

  }

}


void loop() {
  // the offsets were in the loop func
//  myFile = SD.open("test.txt", FILE_WRITE);
//  //Serial.println(F("If this value is 0, you've fucked something up :D")); always gives 0 ?
//  Serial.print(myFile);
//  if (myFile) {
//    Serial.println("Yaaay, we are writing to the file :D");
//    myFile.println("   are ");
//    myFile.print(ax_offset); myFile.print("\t");
//
//    myFile.println(ay_offset); myFile.print("\t");
//
//    myFile.println(az_offset); myFile.print("\t");
//
//
//    myFile.close(); // close the file
//  }
  // if the file didn't open, print an error:
//  else {
//    Serial.println(F("error opening test.txt"));
//  }
//  delay(1000);

  recordAccelRegisters();
  recordGyroRegisters();
  printData();
  Serial.println(F("After this sentence, it should start writing the Gforces on the SD card, so yeah, we did something: \t"));
  myFile = SD.open("test.txt", FILE_WRITE);
  {
     // new line , today, 17 . 07
    myFile.print(gForceX);  myFile.print("\t"); // change to printLN ? 17.07

    myFile.print(gForceY); myFile.print("\t");

    myFile.print(gForceZ); myFile.print("\t");


    cnt++; // increase the counter after writing X times to the file
    myFile.close();
  }

  delay(1000);


  Serial.println(F("This is just for checking the counter status ___ "));
  Serial.print(cnt);
  if (cnt == 10) // increase the counter number for larger data
  {
    myFile = SD.open("test.txt");
    while (myFile.available())
    {
      Serial.write(myFile.read());
    }

    Serial.println(F("File was closed, exiting"));
    myFile.close();

    delay(50000);
  }
}


void meansensors() {
  long i = 0, buff_ax = 0, buff_ay = 0, buff_az = 0, buff_gx = 0, buff_gy = 0, buff_gz = 0;

  while (i < (buffersize + 101)) {
    // read raw accel/gyro measurements from device
    accelgyro.getMotion6(&ax, &ay, &az, &gx, &gy, &gz);

    if (i > 100 && i <= (buffersize + 100)) { //First 100 measures are discarded
      buff_ax = buff_ax + ax;
      buff_ay = buff_ay + ay;
      buff_az = buff_az + az;
      buff_gx = buff_gx + gx;
      buff_gy = buff_gy + gy;
      buff_gz = buff_gz + gz;
    }
    if (i == (buffersize + 100)) {
      mean_ax = buff_ax / buffersize;
      mean_ay = buff_ay / buffersize;
      mean_az = buff_az / buffersize;
      mean_gx = buff_gx / buffersize;
      mean_gy = buff_gy / buffersize;
      mean_gz = buff_gz / buffersize;
    }
    i++;
    delay(2); //Needed so we don't get repeated measures
  }
}

void calibration() {
  ax_offset = -mean_ax / 8;
  ay_offset = -mean_ay / 8;
  az_offset = (8192 - mean_az) / 8;

  gx_offset = -mean_gx / 4;
  gy_offset = -mean_gy / 4;
  gz_offset = -mean_gz / 4;
  while (ready < 6) {
    int ready = 0;
    accelgyro.setXAccelOffset(ax_offset);
    accelgyro.setYAccelOffset(ay_offset);
    accelgyro.setZAccelOffset(az_offset);

    accelgyro.setXGyroOffset(gx_offset);
    accelgyro.setYGyroOffset(gy_offset);
    accelgyro.setZGyroOffset(gz_offset);

    meansensors();
    Serial.println("...");
    cnt2++;

    if (abs(mean_ax) <= acel_deadzone) ready++;
    else ax_offset = ax_offset - mean_ax / acel_deadzone;

    if (abs(mean_ay) <= acel_deadzone) ready++;
    else ay_offset = ay_offset - mean_ay / acel_deadzone;

    if (abs(8192 - mean_az) <= acel_deadzone) ready++;
    else az_offset = az_offset + (8192 - mean_az) / acel_deadzone;

    if (abs(mean_gx) <= giro_deadzone) ready++;
    else gx_offset = gx_offset - mean_gx / (giro_deadzone + 1);

    if (abs(mean_gy) <= giro_deadzone) ready++;
    else gy_offset = gy_offset - mean_gy / (giro_deadzone + 1);

    if (abs(mean_gz) <= giro_deadzone) ready++;
    else gz_offset = gz_offset - mean_gz / (giro_deadzone + 1);

    if (ready == 6) break;

  }
}

void setupMPU() {
  Wire.beginTransmission(0b1101000); //This is the I2C address of the MPU (b1101000/b1101001 for AC0 low/high datasheet sec. 9.2), we use the LOW , a.k.a. ADO is connected to GND .
  Wire.write(0x6B); //Accessing the register 6B - Power Management (Sec. 4.28)
  Wire.write(0b00000000); //Setting SLEEP register to 0. (Required; see Note on p. 9)
  Wire.endTransmission();
  Wire.beginTransmission(0b1101000); //I2C address of the MPU
  Wire.write(0x1B); //Accessing the register 1B - Gyroscope Configuration (Sec. 4.4)
  Wire.write(0x00000000); //Setting the gyro to full scale +/- 250deg./s
  Wire.endTransmission();
  Wire.beginTransmission(0b1101000); //I2C address of the MPU
  Wire.write(0x1C); //Accessing the register 1C - Acccelerometer Configuration (Sec. 4.5)
  Wire.write(0b00001000); //Setting the accel to +/- 4g
  Wire.endTransmission();
}

void recordAccelRegisters() {
  Wire.beginTransmission(0b1101000); //I2C address of the MPU
  Wire.write(0x3B); //Starting register for Accel Readings
  Wire.endTransmission();
  Wire.requestFrom(0b1101000, 6); //Request Accel Registers (3B - 40)
  while (Wire.available() < 6);
  accelX = Wire.read() << 8 | Wire.read(); //Store first two bytes into accelX
  accelY = Wire.read() << 8 | Wire.read(); //Store middle two bytes into accelY
  accelZ = Wire.read() << 8 | Wire.read(); //Store last two bytes into accelZ
  processAccelData();
}


void processAccelData() {
  gForceX = accelX / 8192.0;
  gForceY = accelY / 8192.0;
  gForceZ = accelZ / 8192.0;
}

void recordGyroRegisters() {
  Wire.beginTransmission(0b1101000); //I2C address of the MPU
  Wire.write(0x43); //Starting register for Gyro Readings
  Wire.endTransmission();
  Wire.requestFrom(0b1101000, 6); //Request Gyro Registers (43 - 48)
  while (Wire.available() < 6);
  gyroX = Wire.read() << 8 | Wire.read(); //Store first two bytes into accelX
  gyroY = Wire.read() << 8 | Wire.read(); //Store middle two bytes into accelY
  gyroZ = Wire.read() << 8 | Wire.read(); //Store last two bytes into accelZ
  processGyroData();
}

void processGyroData() {
  rotX = gyroX / 131.0;
  rotY = gyroY / 131.0;
  rotZ = gyroZ / 131.0;
}

void printData() {

  Serial.println(F("Gyro (deg)"));
  Serial.println(F(" X="));
  Serial.print(rotX);
//  if (rotX >= 100) { //                                     <<<<<<<<<<<<<<--------- DELETE THIS FUCKERS, WE DON'T HAVE MEMORY !!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!, NVM FOUND IT :D
//    blinkLED();
//  }
//  if (rotX <= -90) {
//    blinkLED();
//  }
//  Serial.print(" Y=");
//  Serial.print(rotY);
//  if (rotY >= 90) {
//    blinkLED();
//  }
//  if (rotY <= -90) {
//    blinkLED();
//  }
  Serial.println(F(" Z="));
  Serial.print(rotZ);
  Serial.println(F(" Accel (g)"));
  Serial.print(F(" X="));
  Serial.print(gForceX);
//  if (gForceX >= 0.75) {
//    blinkLED();
//  }
//  if (gForceX <= -0.75) {
//    blinkLED();
//  }
  Serial.print(F(" Y="));
  Serial.print(gForceY);
//  if (gForceY >= 0.75) {
//    blinkLED();
//  }s
//  if (gForceY <= -0.75) {
//    blinkLED();
//  }
//  Serial.print(" Z=");
//  Serial.println(gForceZ);
//  if (gForceZ >= 3.5) {
//    blinkLED();
//  }
//}
//void blinkLED() {
//  digitalWrite(LED_BUILTIN, HIGH);
//  delay(5000);
//  digitalWrite(LED_BUILTIN, LOW);
}