Samsung door multisensor keeps going offline

Devices & Integrations
1

I’ve had a slowly growing smartthings setup that has worked very reliably for 3+ years. However recently just one single door multisensor on a bedroom door frame has started causing problems.

It’s a v2 door sensor of the previous design that is more sharp edged and blocky. My understanding is thst this is near identical technically to the latest version Samsung made?

Basically it goes offline constantly. Normally within a few hours of adding it to the setup.

It didn’t to start with when first installed… It worked fine.

It’s not the battery and it’s not even a speicific sensor device as I’ve actually tried multiple identical sensors on the same door frame.

What has changed which I think must be related is that I added a second Samsung v3 hub in an adjacent room fairly recently.

I did that for one specific reason; to allow another door sensor on our front door which is very close to the newly installed hub to work as prior it always seemed to be out of range of my original hub. It makes sense as this front door sensor is the device physically furthest away from the original hub with many thick walls between them.

What’s odd about the door sensor in the bedroom that goes offline is that if I take the battery out and put it straight back in, it starts flashing green and fairly quickly reestablishes a connection to a hub and then works. It doesn’t need resetting. It’s with a new battery that shows 100% constantly within the smartthings app.

So I have a few questions…

  1. is a multihub setup in theory going to work?
  2. are there going to be problems with a device that is likely in reach of both hubs? Is it possibly contacting one then later the other and for some reason getting confused and giving up?
  3. the behavior I’ve seen with how the sensor seems to give up and go to sleep ultil the battery is taken out and replaced is normal? What does it suggest?
  4. can I see somehow which hub the device is actually connected to?

Sorry for the long post but I felt I had to spell all the details out.

Thanks for any input!

2

@orangebucket operates a multi hub set up, so might have some more thoughts in that regard. If you have time, you might also want to check and see what Zigbee channels the two hubs are operating on and post that information, as it might be helpful. This should be available in the IDE under the hub details.

In terms of Zigbee in general, because it’s a mesh network, the distance to the hub doesn’t really matter. What matters is the distance to the next repeating device, and specifically the distance to the repeating device that this device has chosen as its parent.

Battery powered devices generally don’t repeat because it would use too much battery life. Most mains powered devices, such as smart plugs, inline relays, even thermostats usually do act as repeaters. Most Zigbee lightbulbs can act as repeaters, but are generally unreliable. Sengled Brand devices of any type do not act as repeaters, that’s just a decision that the manufacturer made.

So… other than the battery powered sensors, which repeaters are nearby? One reason I would look at this is because it’s the same aspect that would affect any device in that physical location, and you said you had the same problem when you tried a new device there.

1 Like
3

I’d also want to know if you recently (or if your router decided to without asking you) changed ANYTHING about your 2.4Ghz WiFi setup. Or if you moved a computer or anything with USB 3 close to that sensor.

1 Like
4

Thanks for the reply. The only repeaters (mains powered devices) that I have are actually the two ST hubs. All my other devices are battery powered Samsung door sensors and buttons/switches.

There are hue bulbs but I assume that these don’t count.

5

Correct, the hue bridge forms its own mini network with any devices connected to it and so they don’t act as repeaters for the Zigbee network created by a smartthings/Aeotec hub.

With no repeaters, you have what is technically referred to as a “weak mesh.“ How many sensors do you have?

It would probably be a good idea to add a couple of Zigbee repeaters. You can get an IKEA tradfri plug-in pocket socket for about $10 if you buy it from IKEA directly, or a similar price in many other countries. These typically work well as repeaters if you have at least a V3 hub, although there are some reports that they may confuse IKEA buttons when used in a smartthings set up. I’ve used these in my own house and always been happy with them. But there are lots of other choices.

If you’re interested in learning more about building a strong mesh, see post 11 in the community FAQ on wireless range and repeaters. I will link directly to that post. You can click on the topic title to go to the full thread and after you re-post 11 go back up and read the whole thing.

I think you’ll find that most of us who are interested in network functions, and therefore are typically the people commenting in threads like this, try to have pretty strong networks with multiple repeaters. :sunglasses:

Anyway… Adding the second hub would at a minimum have increased some of the Zigbee network “noise“ in your house, which can cause individual devices to have a little more trouble connecting, and without a strong mesh, messages can then get lost. So this issue is definitely something that adding the second hub might have caused.

But you can certainly run multiple Zigbee networks in the same building, I’ve had as many as six or seven at the same time. (On different platforms: I’ve never run two smartthings hubs in the same building, although there are people who do.) It is a good idea to keep them off the same channel if you can and it’s always a good idea to have a strong mesh for each. That’s what protects you against occasional moderate interference.

1 Like
7

No JD - I want them to be able to pick up my RF emissions from Alpha Centauri.

A few repeaters… Rather I only buy a battery powered device if I HAVE to and if so I make sure a repeater is somewhere within 20’ (~6m)

1 Like
8

A few extra Hue bulbs were added recently, the only other change has been the second ST hub.

9

Thanks for the long reply. Just to confirm, what tools/software can I use to really see how my zigbee (and z-wave) networks are setup, what channels they use etc ?

10

Builtin: https://account.smartthings.com

Everyone needs to stay on SmartThings to make sure these get replaced before Groovy goes away (BTW)

Beyond that there are tools available for $ intended to be used with carious zigbee sticks and network sniffers.

2 Likes
11

Thanks, I never really caught on how much info there is when you click into a device on the ST website.

It is apparently connected to my nearby new hub according to the ‘route’ value, which is what I wanted it to do and assumed would make it have a better connection.

The metrics field shows the following… anything really useful here ?
I understand that Last Hop LQI should be well over 200 to be reliable and mine is a rather pathetic 52. Odd as it’s so close to this second ST hub. There is a wifi repeater near this hub so I assume this could be something to do with it. I will try turning off that wifi repeater and see if that helps.

  • Last Hop LQI: 52
  • Last Hop RSSI: -87
  • Received Messages From Device: 376
  • Received Messages From Device (Duplicates): 3
  • Messages Transmitted to Device: 304
  • Messages Transmitted to Device (Failures): 262
  • Updated Time: 2021-12-31 4:55 PM CLST

If anyone can interpret anything else useful from this please let me know.

12

First, just to confirm that you are using the hue bulbs with the hue bridge, right? Although they technically can be connected directly to a smartthings hub, neither company recommends that, and they can mess up your Zigbee network.

FAQ: Do I need the Hue Bridge/Hub to Use a Hue Bulb with SmartThings?

If you added them to a hue bridge which was already connected to your smartthings account, they shouldn’t have any impact. Maybe add a little more noise in the immediate environment, so you might want to check the channels, but shouldn’t be a big deal. There’s typically very little traffic on a hue network.

If you added them directly to a smartthings hub, then, yes, they can cause a lot of problems. See the FAQ I just linked to.

As far as mapping your smartthings networks…

SmartThings provides very few built in tools, significantly less than competing brands. :disappointed_relieved:

If you go to the IDE, which is the web interface from the old architecture to your smartthings account, you will at least be able to tell the Zigbee channel for each hub under the hub details there. That’s the link that @nathancu just gave you.

You will also be able to see a single route path reported for each zigbee device. But it’s not real time, and it’s not necessarily the most commonly used path, it’s just the last one that the cloud happen to record for this reporting. It’s better than the nothing that we used to have before, but not a whole lot better. :thinking:

If you want to get a real map of your Zigbee and zwave networks you have to buy another device from another company, add it into your network, and then use that device’s network tools. Which is doable, but expensive and annoying.

FAQ: Mapping your ZigBee network with Digi's XCTU
.

ZWAVE TOOLBOX: third party diagnostic tool

13

262 failures out of 304 attempts is, well, horrible. So, yes, there’s definitely a local signal issue. It could be architectural, like if you live in adobe house, it could be RF. How many other Zigbee devices are connected to the second hub?

Removing the Wi-Fi repeater would definitely be my first step, those can drown out almost anything Zigbee nearby.

14

Best case IF that second hub repeats for the first hub is you need to use the procedure, I mentioned above to TELL the device to hunt for new routes.

Worst case it may actually be making matters worse. SmartThings did not support multiple hubs in the same location for a LONG time and I don’t think they officially do yet. (JD do they each form their own mesh? If they do can two hubs on the same channel stomp on each other?)

15

They do now, but it’s complicated.

There are two possibilities.

  1. SmartThings WiFi mesh hub has a master hub and you can add subs to it. In that case they are all on the same Zigbee network. Model ET-WV525KWEGUS.

But I don’t think that’s the set up here.

  1. if you are using the regular smartthings hubs, any model, you can add more than one to the same smartthings account. Each one will form its own Zigbee and zwave network. An end device like a sensor can only belong to one of these networks.

So you won’t get two hubs on the same network. But if they are on the same Zigbee channel, then you can get interference just like you would between any two Zigbee devices that are physically close together.

As far as what you’ll see in the app under that set up, I have to leave that to others to discuss. Graham is in the UK, so we probably won’t hear from him until another eight hours or so, and of course a lot of people will be busy for the holiday.

1 Like
16

Then that’s what I THINK is happening here. they all default to channel 19 don’t they? :slight_smile: OP’s new hub is ‘literally right next to the sensor’

17

I am not sure I can add too much to the conversation that hasn’t already been said.

I have three ST hubs. Two are on the same SmartThings Location and one on a second Location. I have made a point of assigning them different Zigbee channels, and keeping those channels as far from my WiFi channel as I can. Also the WiFi router is physically well away from the hubs, as is a WiFi extender which I only use as required. I also have an IKEA Gateway. I don’t actually know what channel that is using for sure, though I hope it is 11.

I only have three hubs for ‘play’ purposes. I did once have a need for a second hub to help me handle certain Zigbee devices better but I’ve got rid of those.

In a SmartThings context the issues causes by multiple hubs are:

  • Adding hub connected devices by brand or type in the Android app is broken for multiple hubs (regardless of Location). It did work fine but has been broken for six months or so now.
  • Locally executing automations are hub specific. More generally automations tend to be Location specific. So basically you need to be conscious of which hub devices are connected to.

So there is nothing fundamentally wrong with using multiple hubs but it is not a neutral move.

More generally, each hub will be creating it’s own separate Zigbee and Z-Wave meshes. Each device will only be on one so they can’t get confused. However unless you actually need separate meshes adding a hub might just be doubling your number of weak meshes for considerably more money than strengthening the ones you have.

From what I have been reading in this thread, I’d have been trying a repeater or two rather than a second hub as I think it gives more benefits. However that sounds like a side show to the fundamental problem.

The problem is that you can be dealing with very fine margins. I used to have the SmartThings presence sensor key fobs. You could put those down attached to keys and they might not be able to connect. However you could rearrange the keys by a few millimetres and they’d be fine.

1 Like
18

Sounds plausible. Mine are all V2 and selected their channel from a limited range on hard reset, but something about channel 19 is familiar.

I don’t think I’ve ever had hubs on the same channel for even a short period, not even by chance.

19

Thanks for all the feedback guys. I think the point about defining channel settings isn’t that relevant in my case as its for the configuration of zigbee and the problem devices are z-wave.

I’m going to basically improve the position of my new 2nd ST hub and put more distance between it and the nearby wifi router and then I will report back.

20

No if its a Samsung branded sensor, I GUARANTEE its Zigbee. Samsung/SmartThings never made branded ZWave devices

2 Likes
21

Originally, up through V2, SmartThings hubs chose their Zigbee channel randomly at initial setup based on local interference, with 14 being the most common for some technical reasons having to do with the
ZHA profile. But 14 could cause issues for ZLL devices. The only way to change the hub’s Zigbee channel back in 2015 was to factory reset it and start all over, hoping to get a different channel in the next random selection. Very tedious. :rage:

Now ST allows you to change it, which is good.

19 is a nonZLL channel, so it would surprise me a little if that’s the current default, but I don’t know.

I think 11 is the most common default channel for DIY Zigbee hubs. Yes, it will run into interference with WiFi channel 1, but from a customer support standpoint it’s just really easy to tell people to put both the Zigbee hub and the WIFI router on channel 11 and avoid interference that way while still allowing an easy add of older ZLL devices.

@nathancu

1 Like