simple LANC start stop button

So now I have until December before my camera arrives. Can someone please come up with a simple start stop button for the camera? I never wanted zoom or focus or anything else, just a switch that you either press once to record and once to stop, or one you have to hold down to record. A button like proper film camera.
If someone from Blackmagic felt like posting the requirements I'll even teach myself soldering to do it myself!
If someone from Blackmagic felt like posting the requirements I'll even teach myself soldering to do it myself!