I also posted this on the ST community but I wanted to get some insight on performing a physical integration with the Nest Protect.
I would like to integrate my Nest Protect with a Arduino/Konnected/RPI/etc that can communicate with SmartThings/Hubitat. I took one of my Nest Protects apart (battery version) to determine the ideal method for physical integration.
Tap into the siren (EFM 290edfp)
Put a color sensor that can tell ST/Hubitat when the status lights turns red (indicating an emergency).
I tapped into the siren and connected a voltmeter to see what kind of behavior I get. Here is a video: Dropbox - Siren.MOV - Simplify your life
As you can see the siren turns on and off so it is hard to see what the voltage reading is.
What are you thoughts - can I integrate this with a Arduino board (like the ESP8266)?