Originally Posted by vinhteo
I think nokia (Microsoft) has not applied "double tap to wake the screen" technology to the nokia x. so they used the sound sensor or some thing else to replace. I guess so.
to turn it on: setting - Display - sreen double tap
to wake your Nokia X up easier, you should double "Knock" on it. No touch, you touch on sreen willl not work
Knock every on Nokia X, better near microphone and body
You shoud use Screen Security - lock sreen to prevent accident wake up
Nokia makes use of the Vibrator and Accelerometer to implement Double Tap on these devices. This is same for the Nokia 5XX series.
Hence, the output is not so great. Sometimes you need to tap really hard and at other times even hitting the phone at its back would wake it up.
There's one or the other thing that is sacrificed. To reduce wastage of battery, the screen was not used to implement this feature.