I found the answer my self
in case anybody needs it I'm posting it in here
the default sensitivity range for the accelerometer is +-2g which is equal to 16384*2, in which 16384 LSB is equal to the gravity acceleration 9.81m/s^2
in the source code of mpu6050.cpp line 66 the range has been defined as follows
setFullScaleAccelRange(MPU6050_ACCEL_FS_2);
by changing the number 2 into 4 the range is also changed into +-4g and the sensitivity accordingly to 8192 lbs.
Hi 33chen, my apologies for opening this post again
it's true that it's easy to change the range in the provided code by jeff rowberg, but I couldn't find any post about it in this forum.
can you please help me how to do it.
thank you