Hi all
Looking to buy a couple of motion sensor that i can mainly integrate with ST , had an original motion sensor for ST , the square one , but it died completly , and wondering if i should try to find the new ones made by ST or if you guys recomend other ones ???
Already have the house with dorr/window sensors , and cameras , and the alarm siren , looking for reliable motion sensor what can i buy ???
Thanks
might be hard finding sensors made by ST. they are getting out of the hardware business and they are currently difficult to find. 
what can i buy that is reliable , for motion sensor ??? and that works with ST ??
i will leave that to others to answer.
I got some of the Xaomi aqara motion senors with a custom DTH and they’re fine. I have one of the ST ones though and that’s really good. I would probably try for those if you can but the Aqaras are a good 2nd option.
What country are you in? The device selection does vary.
Also, do you have a preference for Zigbee over zwave?
I don’t know how reliable is, but there is Ikea motion sensor in almost any country.
I do use one in my mailbox, for last couple of weeks and is working for now
I have had a great experience with the Iris motion sensor. They do motion, temp and humidity.
I have three of these, even along with the device handler, they’ve all failed. They work for a period- then stop communicating.
I’d be curious to see what others recommended as well, I love using motion to trigger things.
I will 2nd the IRIS Motion Sensor IL07 3rd Generation as being a good detector.
We still need to know what country you are in. 
i guess i need to amend my post above where i mentioned it would be difficult to find ST motion sensors. Rebranded Aeotec motion sensors for ST in North America will be available at some point in 2021.
This is worth a look as well:
Nice find! The video is very well done.
If anyone knows the presenter, three small things:
The term he’s looking for to describe the area in which motion will be detected is “detection zone.“ So there’s “field of view,” which he uses correctly throughout the video, and “detection zone.“ Not “range,” which he clearly knows is not the accurate term, he just doesn’t know what to substitute for it. Security companies will say “when something enters the detection zone,“ and put out documentation marking the lines of the detection zone.
PIR sensors, which all of these are, should be placed at a distance from heat sources or you will get additional false positives. He’s got one that’s on a light and another one that is on the stove itself. Both of those are likely to get false positives.
for PIR motion sensors, it’s helpful to know that motion (really, change in heat) is detected as it passes across the lens, not moving towards the lens. So some of his sensors are going to take longer to detect than they would if they were just moved 90° to the current placement. See the FAQ:
FAQ: Where to locate motion sensor for fastest response?
Again, those are small points, and don’t detract from the excellent level of detail in the video. 
The video is very badly done, it’s clearly obvious he hasn’t spent much time with most of those sensors.
Two other small things while I’m thinking about it:
The community has found that IKEA Tradfri pocket sockets and bulbs are good repeaters to use with aqara devices. Of course getting the motion sensor to use only one of those requires some finagling, so it’s still a limitation of aqara sensor, but there is a repeater option for those who want to pursue it.
it’s often the better engineered sensors that have a narrower field of view because that will help reduce what are perceived as false alerts. That is, sometimes a smaller detection zone is better, particularly for lighting use cases. But it’s not really that the wider field is better or worse, it is that they are different and you will want to choose one that matches the use case you are looking for.
Separately, he really should add the Fibaro multisensor to his review, it’s a popular device and probably the most customizable in terms of parameter settings.
The same situation. Work for same minuts and after or disconnect, or not disconnect but they no longer detect any movement. I begin to hate Aqara, I’ve been arguing with them for a week and I can’t make them work as well as I would like
well , thank you @Pogga , the video was very helpfull , since i had a hue motion sensor , but never added it to ST , and in the video showed my the DH and after i added , i just see that it works very well , at least so far , going to keep testing it , but here in Europe i can buy the HUE Motion sensor for arroun 33 € , so if it works well ill go with this option since the ST alarm works with them .