im trying to make my cellphone a remote control for my dslr (but i need help)

[Cap_Winters]

Hi everyone 

I wanted a intervalometer ,but I don’t have money ,so I after watching a few tutorials I found this app :

https://play.google.com/store/apps/details?id=de.dslrremote&showAllReviews=true

http://bitshift.bplaced.net/en/dslr-remote.htm

I found lying around in my house a 3.5mm cable to 2.5 mm.

it works!!! but when I use the time-lapse it shots two pictures instead of one.

The theory that I have:

My cellphone outputs to much energy or signal .o for a longer period of time  forcing the camara to shoot twice.

I have a Moto G5 but I tried whit several older phones and it didn’t work.

I think this is the solution: http://bitshift.bplaced.net/en/dslr-remote/hardware/cable-a---opto-couplers.htm

but I don’t have  any soldering knowledge and I don’t know if I can buy that in my city.

If anyone knows how to solve this let me now.