Open Tasker, Raspberry Control Slider and Timelapse with Smartphone

Hello,

I currently use Tasker with several plugins to timelapse a smartphone camera.

I would like to make it more advanced the script, so i after i followed this tutorial:

http://blog.koivistik.com/pilapserails-raspberrypi-time-lapse-rails/

i motorised a slider, install that software on raspberry pi and control the slider.

What i want is, to be able to make a task from tasker, to control comunicate with gpio from raspberry pi, so i could move the slider one direction on certain time.

As i saw in that software, it was comunicating trough GPIO.

So ideea is: to have the phone on the slider, and control it from another phone.

Tasker to do:

open android camera app
move slider 10cm for example stay 10seconds
android camera take a picture
again move slider 10cm take picture
for certain amount of time

Any ideea how to do that?

Thank you

Regards

Sebastian