I recently replaced all my smoke detectors; my house has them hardwired and interconnected. I wanted notification if they went off, but I don't want the smoke detectors at all involved in my home automation. I went with regular hardwired, interconnected detectors by Kidde. To link them, I used a Ecolink Firefighter, which mounts next to one of the detectors and listens for the specific sound they output.
(there is also a interconnect relay I could have used, but this was a simpler installation, and the two systems are completely independent)
