I want to control zoom or focus of my Android phone's camera using audio jack. It is common to use audio jack to take picture or probably we may call it as shutter. It is done by connecting the mic port and the ground as shown in the picture 2 (I took it from here. It is not Android, but probably the same idea is possible with Android). Is it possible to do zoom or focus using the audio jack? Say, like we manipulate or rearrange it something like explained in picture 1? Picture 1 taken from here.
The Android specification for the audio Jack, this gives you the input/key events that can be generated by the audio jack. Your camera application should listen for these events and do the appropriate action.
How to create hardware to generate the events is here