CodeForArduinoNano.ino

#include <SoftwareSerial.h>
SoftwareSerial BT_Serial(2, 3);  // RX, TX

#include <Wire.h>  // I2C communication library

const int MPU = 0x68;  // I2C address of the MPU6050 accelerometer
int16_t AcX, AcY, AcZ;

int flag = 0;

void setup() {  // put your setup code here, to run once

  Serial.begin(9600);  // start serial communication at 9600bps
  BT_Serial.begin(9600);

  // Initialize interface to the MPU6050
  Wire.begin();
  Wire.beginTransmission(MPU);
  Wire.write(0x6B);
  Wire.write(0);
  Wire.endTransmission(true);

  delay(500);
}

void loop() {
  Read_accelerometer();  // Read MPU6050 accelerometer

  if (AcX < 60 && flag == 0) {
    flag = 1;
    BT_Serial.write('f');
  }
  if (AcX > 130 && flag == 0) {
    flag = 1;
    BT_Serial.write('b');
  }

  if (AcY < 60 && flag == 0) {
    flag = 1;
    BT_Serial.write('l');
  }
  if (AcY > 130 && flag == 0) {
    flag = 1;
    BT_Serial.write('r');
  }

  if ((AcX > 70) && (AcX < 120) && (AcY > 70) && (AcY < 120) && (flag == 1)) {
    flag = 0;
    BT_Serial.write('s');
  }

  delay(100);
}

void Read_accelerometer() {
  // Read the accelerometer data
  Wire.beginTransmission(MPU);
  Wire.write(0x3B);  // Start with register 0x3B (ACCEL_XOUT_H)
  Wire.endTransmission(false);
  Wire.requestFrom(MPU, 6, true);  // Read 6 registers total, each axis value is stored in 2 registers

  AcX = Wire.read() << 8 | Wire.read();  // X-axis value
  AcY = Wire.read() << 8 | Wire.read();  // Y-axis value
  AcZ = Wire.read() << 8 | Wire.read();  // Z-axis value

  AcX = map(AcX, -17000, 17000, 0, 180);
  AcY = map(AcY, -17000, 17000, 0, 180);
  AcZ = map(AcZ, -17000, 17000, 0, 180);

  Serial.print(AcX);
  Serial.print("\t");
  Serial.print(AcY);
  Serial.print("\t");
  Serial.println(AcZ);
}