Detecting the direction of the accelerometer movement on the y axis

I currently detect movement on the y axis. How does one calculate the direction it moved on the axis?

I get开发者_运维问答 the same values when moving up or down.

Is the Gyro needed for this?

Do remember that the accelerometer will reflect the force of gravity. So movement up and down will generally be reflected as 9.81 m/s² plus or minus the actual acceleration of the device relative to the Earth.