New Motion Sensor - Distance from hub

I bought one of the new ST motion sensors to use in my walkin closet to turn the light on when you walk through the door.

It worked good for two weeks and then stopped. I reset it three times and it would maybe work once and then get stuck in “motion” or “no motion”, but not respond.

I contacted customer support and they mentioned the 40 ft distance to the hub was on the outside of the spec because the new motion sensors are “unamplified” to meet UK specs? Battery(88%) and temp are both updating so seems it’s making some contact.

Does anyone have the new version of the motion sensor and what distance limitations have you experienced?

I’m having the same issue

I wondered how that was all going to work out. I’m sure it’s very frustrating.

Here’s the situation. Zigbee uses the same frequency all over the world. And the zigbee home automation profile (ZHA 1.2) is the same communication protocol all over the world.

However, in Europe, the ETSI has specifically Limited the signal strength for all radio frequency devices. It’s strictly a power issue. But it’s a very complicated formula that has to do with the strength of any spikes in the transmission. Basically you end up with strength of about half of what’s allowed in the US and Canada. This is sometimes called “amplified zigbee” or “boosted Zigbee” but there’s no official name for it.

Some devices have a setting so that you can dial the power down and make it legal for either Europe or the US. Some have just one setting. If that one setting is at the maximum allowable US level, then you cannot use that device legally in Europe.

Obviously, the higher the power, the farther the distance at which the signal can be detected.

All of that said, if you’re getting temperature reports from the device, you should get motion reports all of that said. So that’s just odd.

Why don’t you try moving the device about 10 feet from the hub for a couple of days, and just see if it reports motion there. You don’t have to trigger any events off of the motion, just see what’s in that log.

I suppose it is possible that if you’re right on the edge of the maximum distance and the device is sometimes able to connect and sometimes not that the motion events are occurring at times when the connection is bad. That’s not impossible. There’s a wake up process for the device which is handled differently for the temperature report than for the motion report.

In any case, if the device works fine when it’s 10 feet from the hub, then you just need a repeater between it and the closet. Most mains-powered ZHA zigbee devices will work. Or if possible you could move the hub to a more central location.

Thanks for all the feedback. I reset it again and it does NOT detect motion 10 ft from the hub, so just going to send it back for a replacement. It worked flawlessly for two weeks, so I have always been suspicious it was just gone bad.

What’s the battery life at? It might just be a bad battery.

88% and the temp is accurate

OK, then yes it could just be a bad device. It happens.