SmartThings Community

Door Sensor out of range / Aluminium Doors

Hello Forum,
I’ve just purchased a hub and sensors to create a home security system. It all works great except when it comes to my outbuilding which is the main reason I’d like security.

The outbuilding has some very large aluminium and glass bi-folding doors. When I stand outside of the building, the hub picks up the open/closed signal from the Smartthings Multi Sensor absolutely fine (so the range is fine). It’s not actually that far away from the house.

However, as soon as I install the sensor on the inside of the door it becomes very unpredictable. It seems that the aluminium doors are blocking the signal.

In order to the strengthen the signal, I purchased a ST Power Outlet as I heard that as it’s a wired/powered device it can help boost the Zigbee signal… but nope, it’s had no effect.

Does anyone have any ideas? I guess I could try installing the sensor on the outside and weatherproofing like some other folks on the forum but it’s not ideal. Or, maybe, another Zigbee extender but I’m reluctant as the Power Outlet hasn’t worked. Would some rubber between the aluminium frame and sensor work maybe?

Any help would be very much appreciated. I’m pulling my hair out…!

Thanks.

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What happens with the sensor if you’re in the outbuilding with the doors open? Does the signal survive?
Just making sure the range is confirmed and tested to be okay (it sounds like it should be based on working just outside, another foot shouldn’t put it out of the effective range)

Just tried it to double check… when the door is open the signal works fine. If I walk further into the building at a place where the signal has to travel through the glass in the doors it doesn’t work.

Have you tried this? I also wondered whether rubber would work but I worry that once the door is closed the signal to say it is closed gets blocked by the metal frame.

I’ve found that it almost “stores up” signals so if the door is closed and you connect and disconnect the sensor a few times, once the door is opened the signal flashes open/closed/open/closed to “catch up”.

You could try this just with anything you’ve got lying around that will move it 1/2" or more off the surface off the door and frame.

I personally have not, but I understand the physics behind it… Anything non conductive should help.

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I’ve not tried the actual plastic case the sensor came with. I might try that and report back.

I’ve just tried fixing some large plastic backing to the sensors (an inch thick) and trying the sensors but it doesn’t work.

I don’t think changing the backing to a non conductive material is going to work in my case as when the doors are closed and I’m holding the sensors in my hand opening/closing manually it still doesn’t work. The windows/aluminium frames are blocking it.

If the aluminum is already magnetized it may take a few days to weeks to de-magnetize. Also metal and RF (zwave/zigbee) don’t play nice anyway.

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Thanks for the link. Interesting… but frustrating having to wait for an unspecified period of time before the metal is de-magnetised.

Would this also explain why the sensor doesn’t work when I’m inside the building with the doors closed and trying to open/close manually? Is a magnetic field getting in the way of that?

Physics matters: aluminum doesn’t magnetize. So that’s not it. ( you can test this easily enough. Take a kitchen magnet and see if it will stick to the door frame. If it doesn’t, the material is not magnetic and cannot interfere with the sensor in the way described in the gate topic.)

http://directmetalsrecycling.com/steel-vs-aluminum-how-can-you-tell-them-apart/

Aluminum can still however block signal.

Zigbee repeaters do not boost the signal, they just pass it along. So if you’re putting the mains powered device inside the same out building, it’s not likely going to help. You won’t be able to get the signal to it either. Repeaters are used to extend the distance. But they can’t increase the signal’s ability to move through a blocking material.

Try the following topic (this is a clickable link). It discusses most of the issues you run into with outbuildings.

And this one discusses some additional options. Your idea of rubber seals can work very well. They tend not to block signal but they do block cold air. Mostly you’re just trying to find a way to create a path for the signal from one additional options.

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Thanks for your brilliant response. Having read everything it seems getting another hub inside the building and wiring that up would be best.

Question, would a hub work via an Ethernet extender via the power/mains circuit like a Edimax Powerline adapter? I can’t really run a proper cable.

There are two rooms to my outbuilding, the closest to the house is a utility room with mains plugs. There is a breezeblock and plastered wall inbetween this and the room with a large aluminium doors and windows. I have actually managed to get the ST Power Plug outlet to work in this room hoping the signal would be able to penetrate the breezeblock and use a repeater but that doesn’t seem to work either.

Finally, I do have an outside light right next to the door that I wish to put the multisensor. You’ve mentioned that a repeater doesn’t boost signal but just carries it… But if I got a Zigbee bulb for this light do you think with it being so close to the window it has a hope of working?

Update… To solve this I purchased a second hub installed inside the building and set up as a separate location. Then I used a Powerline adaptor to Ethernet from the building to my hub inside the house. It code an extra £130 but worth it for all the hassle of figuring out another way!

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When it’s important to have control inside the outbuilding, I do like putting another hub there, if only because of weather issues. Otherwise you run the risk of a set up that works well until it rains or snows. Defining the second location avoids all of that. :sunglasses:

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you can get it on one hub…
no one asked what kind of sensors… if st ones they are probably zigbee.

get zwave sensors and install a switch or booster inside the door.
and another inside the house on the wall nearest the outbuilding…

I got a temp sensors working in an ancient freeze that was solid metal and would not work without the booster above it.

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Interesting. I guess that could have worked but in the UK the sensors you can get are limited (without waiting ages for a U.S. one to be delivered!)

As a side note, do US z-wave or Zigbee devices work on a different frequency to the UK? Can I buy something from the U.S. and have it work here?

The short answer is no.

The long answer is in the international FAQ:

The smartthings hub itself is sold in one of two Zwave frequencies. The UK one will work only with devices on the UK zwave frequency. The US one will work only with devices on the US Zwave frequency.

The zigbee sensors and other SmartThings-branded devices sold for the US hub use “boosted Zigbee” which is illegal in the UK. So again you need to get the UK version.

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First of all, your freezer has no rubber seal around the door? (Physics matters.)

Second, while it’s true that Zwave plus has a longer range than Zigbee, Zwave is more commonly scattered by rain. Most outdoor installations use Zigbee for this reason.

Submitted with respect.

Well I also have a wave door sensor in my metal mailbox. Over 140 feet and it works fine as soon as I out a zwave switch in the closest inside wall to the mailbox. No rubber in mailbox. If he has power in the outbuildings he should be able to out a wired outlet or booster at both ends and it should most likely. My zigbee range even with a booster outside is not near as good. But your have to get UK channel wave devices as you mention.