Updated Accelerometer Calibration Solutions?

Hello, I would like to know if there is any other updated solutions about accelerometer calibration because both of the offset solution (which save the initial input accelerometer and then use it as an offset) and this solution did not work for me.

Well, the first solution partially did, but in a situation where the device is on the table (face up), it will not work.

I also found this link and it did not work also (similar to the second solution)

I am not sure where to get help since this thread is already abandoned and the solutions discussed here don't work anymore.

Please help, Thanks in advance.