Devices we don't have

[JDRoberts]

@rontalley

I really don’t understand why there isn’t a simple outdoors motion sensor… Settled on using Blink XTs for Back Door and Garage and Ring Pro for Front Door. However, these solutions are on the “costly” side.

Physics.

Cheap “motion” sensors are really PIR sensors, and that technology just doesn’t work really well outdoors.

There’s a detailed discussion of this along with alternatives in the community FAQ:

FAQ: Do you know of an outdoor motion sensor?

I am looking for outdoor motion sensors to monitor my yard. I bought a pair of the Aeon Labs Aeotec Z-Wave Multi-Sensor and am quite unhappy with them. Even on the lowest sensitivity setting it randomly sends alerts, some perhaps due to clouds changing the lighting (even though PIR is not supposed to be susceptible to this) and others I can’t explain at all. With several false alerts a day this thing is just useless. The Smartthings Motion sensor works great, I have some in my house, but it is indoor rated only. The Schlage / Nexia motion sensor is also indoor use only. I am hoping someone has come across an outdoor rated motion sensor they have been able to pair with the Smartthings hub.

But the short answer is that a reliable one cannot be made at the price point that people using DIY solutions typically want.

Your solution of using cameras with built in motion sensors is really the most cost-effective one for reliability right now.