I’m taking the leap into Arduino land. I’m moving into a a home with a preexisting security system consisting of contact sensors and motion sensors. Here is what i hope to accomplish.
Phase 1
I hope to piggyback on the existing contact sensors in doors/windows adding them as (virtual) 'Things" into my SmartThings environment while also leaving them intact with the current system.
THE PLAN
After reading a ton of forums I believe that I can accomplish this with a Arduino Mega and a SmartThings Shield with this Sketch and following all of this fun ReadMe supplemented by this post on Virtual devices
The part I’m not totally sure on is splicing the wires from the existing security system into the Arduino. I haven’t gotten my filthy hands on the existing system but a cursory glance looks that each contact sensor has two wires and is the normal magnetic kind. I’m hoping the voltage drop is enough so I wont have to do any fancy breadbox work. From what I have read it sounds like I should splice a wire off the existing system’s contacts onto one of the boards pins and repeat for all the sensors.
Now the questions.
Do I need to splice the second wire from the existing sensors? I get the feeling from this post that I need to hook something to the ground on the Arduino board but I’m unsure if I need to do this for multiple sensors, just one, or at all.
I’m assuming that I only need the ST_Anything_Doors_Windows Sketch with the corresponding libraries to accomplish this task. Is that correct?
I’m going to screw up the coding part of the project as my coding knowledge is only slightly better than the average person. Not really a question just a forewarning of the impending broken code i may post.
Phase 2
If I somehow accomplish Phase one and the stability/Maintenance/Kludge of phase one doesn’t drive me insane I’ll process to complicate everything by adding the preexisting motion detectors to the mix.