Just an FYI to everyone setting up their new sentinels and bridges a word of warning. The Raspberry PI3 bridge will overheat, when laid flat on a desktop for instance, and connected directly with a LAN cable. Apparently, it’s working harder because of better bandwidth compared the second one, which is connected via WIFI only. In my case, the app crashes when the PI overheats. There is a temp warning on the dashboard of the app in the upper right corner of the screen. You have to manually restart the app. Which is a problem for a standalone device.
I made some “legs” for the base with some 3/4" long #8 machines screws and bolts that raise the frame a half an inch off the surface. Overheat warning is gone now. I suggest that you implement a method of auto-restarting the app if it crashes! But I’m no coder so I have no idea what’s involved.