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?

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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.