What is the most reliably refreshed temperature sensor?

(Collisionc) #1

Relevant items:
Hub v2
Netatmo Weather Station
Hue Lights
Smartthings Motion Sensor v2
Harmony Hub w/ 2 activities
Activity 1: Turns on portable AC unit via IR
Activity 2: Turns on portable heater via IR

I’ve setup the room above the garage as my computer cave, and as many people know, these rooms are notorious for being poorly insulated. I’m renting the place, so I’m not going to put a bunch of money into fixing the insulation, instead, I setup a virtual thermostat to keep the room at a reasonable temperature. (Although, to be fair, I’ve probably spent just as much doing this as it would have been to fix the insulation… at least I can take this with me.)

The portable AC is turned on via the virtual thermostat app toggling a virtual switch which toggles the logitech activity whenever the motion sensor goes above 76 F degrees, and is turned off when it goes under. I wish Logitech had an open API.
The portable heater is very similar, via a 2nd virtual thermostat app and works under 67F.

The problem i’m having is that the motion sensor does not update the temperature consistently. It detects movement without any issues, as that triggers the hue lights to come on, but it doesn’t update the temperature. Currently, it is reporting 71F, when it’s actually 80F according to netatmo. Refreshing it manually will occasionally work, but that’s just annoying and doesn’t fix it everytime.

I also tried out the pollster smartapp, it worked for about 12 hours then seemed to lock up my zigbee network as all zigbee items were reacting extremely slowly, and the slowness went away immediately after removing the smartapp. I was using a 15 minute polling time.

I mention that I also have a netatmo because I was originally using that as the temperature sensor, and it was consistently updating itself. However, after 3-4 days it would completely stop and I would have to refresh the login information by editing it and pressing next to proceed.

So, is there an item out there that I can use in this situation that I won’t have to babysit? I’m thinking of duplicating the thermostats so that they will trigger from either the netatmo or the motion sensor, but that’s kind of a bandaid fix.

(sidjohn1) #2

This device does not require polling, it updates the hub when there is a temp change and it is not uncommon for temp sensors in general to be inaccurate regardless of manufacturer. Also if there are a lot of wifi networks (or even your own depending on channel) you could be experiencing missed updates due to zigbee network issues. Something to look into if your hub/zigbee repeater and sensor are more than 30ft away or has to passthrough more than 2 walls to communicate with each other. I have found the SmartSense Multi Sensor V2 to be considerably more accurate than the V1 version but have not tested it against an analog device.


One of the reasons why I hate zigbee, and its interference of Wifi. What is the benefit of zigbee anyways. Any recommended zwave temperature modules?

(Collisionc) #4

I don’t mind if they are inaccurate, I just want them to update reliably. I can calibrate around inaccuracy, I can’t calibrate around a device that forgets to tell me the temperature has changed. If the device is inaccurate to the point that it can’t tell the difference between 81 F and 71 F, then Samsung shouldn’t have even included a temperature sensor in the device.

The hub is located in the same room, roughly 10 feet away and has line of sight. :\

(sidjohn1) #5

You may want the hit up support, support@smartthings.com

(Unni) #6

I am actually in touch with support for the same issue. In my case, ST temp/humidity sensor doesn’t update as reliably as the ST multi (both v2). Initially, support said the sensors update only when there is a change in temperature. Today, I kept both the sensors side by side to test further.

The screenshot below shows the reading from multi (left side) and the temp humidity (on the right side).

Between 9:08 am and 7:09 pm, multi sensor reported 7 temperature readings – 71, 72, 73, 74, 75, 74, 73
Temp/humidity sensor reported only 3 times – 73, 74, 73

(Keith Croshaw) #7

Are you in the US? Zigbee in the US operates at 915 MHz while Wifi operates at 2.4 GHz and 5GHz therefore there should be no interference.

I see that Zigbee operates in the 2.4 GHz spectrum “Worldwide,” whatever that means so I could see that causing a problem. I have a feeling ST likes it so much here in the US is due to it’s different frequency that the one that we already have flooding our houses.

Now if only the Smart Multi would stop interfering with my baby monitor… Oh RF…


Yeah, I’m in the US, everything I had read said Zigbee operated on the 2.4ghz, and could cause issues with wifi so since then i’ve stayed away from them. Because just like you, I have a baby monitor that just loves to mess with the 2.4 and vice versa.

(Keith Croshaw) #9

Yea, that “worldwide” part is confusing. Good to know that you’re in the US and it’s 2.4 GHz. That might affect my future purchasing decisions too because I’m having WiFi issues throughout my house lately.

(sidjohn1) #10

This may help, it’s how wifi channels and zigbee channels frequencies overlap. To my knowledge you can’t change the zigbee channel on smartthings, but you should be able to set your wifi to a channel that shouldn’t interfere with your zigbee network.


I think part of the problem is you can not control the channel, so wouldn’t zigbee just choose 1,6,11 automatically?

I’ve had this problem with the baby monitor. It just seems the baby monitor doesn’t care what is out there, well as you know we got ton of wifi around the area, so 1,6,11 all have something on them. I can change my router to another channel and everything is working great, that is until i reboot the monitor and then it decides hey, channel 1 looks nice and messes up my wifi again.

As for ZigBee, i dont’ know how much trouble they would cause, i just know how much trouble this baby monitor gives me and I didn’t want to go buy a bunch of other 2.4ghz devices to sit around the house. So I figured hey ZWAVE looks awesome, why not zwave everything, no wifi problems at all. What advantages does zigbee have over zwave? I think i read something that zigbee is easier on batteries, but then again i dislike battery only devices :stuck_out_tongue:

(sidjohn1) #12

Those are wifi channels not zigbee, I’ve only see the ST hub choose Zigbee channels 15 and 20, but that is just my experience. Most wifi setups will allow you to choose the channel you want to use along with an automatic option and it’s possible that “automatic” will choose whats best for wifi, but not for zigbee. In this case “automatic” is probably not for you and hard setting may be a better option. Also there are more channels than just 1,6,11 they are just the most common non-overlapping channels. In the US channels 1-11 are all valid choices and may or may not work better depending on other devices using the same frequency i.e. bluetooth or zigbee.
In my config, my hub is on zigbee ch 20, so i hard set my router to wifi channel 1 to give the networks as much frequency space as i can, but i was having issues with zigbee devices and i found this config helped my setup. As with any network tweaks, YMMV and i always recommend to test then change then test again till the best settings are found for your setup.
Most importantly if your Wifi and zigbee devices are working fine, then i really don’t see a need to fix something that isn’t broke :wink:

(John Crabtree) #13

CollisionC did you ever get a satisfactory answer to your question? I am having the same issue you did and would be interested.

(Matt) #14

have you looked at the HSM200? Its a plug in model so no batteries and it updates constantly. I have them in all my rooms to control smart vents and it works flawlessly.

(Collisionc) #15

Netatmo - Still has the 2-4 day refresh problem. It’s really unfortunate because the device is awesome outside of the crappy integration with Smartthings.
Motion sensor - Just doesn’t update temperature enough to prevent the room from becoming a sauna

However, the one device that has worked extremely well is -

I initially was trying to avoid buying the Fibaro just because the color led is annoying to me, but then realized that it was possible to completely turn it off via the community-made device handler. What’s also really useful about it, is that I am able to tweak the interval of temperature measuring, and the change in temperature that is required to update the hub. The default interval is 900 seconds, which is just too long for the purpose I’m using it for, so I set it at 300 seconds instead along with updating me if the temperature changes by 0.5 C instead of 1C.

Sure, the battery will likely die in it faster than it would have otherwise, but it is rated for 2~ years of battery life and even if I have to replace the battery every year it’s a significant improvement over having to refresh netatmo’s login every 2-4 days. It has also handled power outages significantly better than most of Samsung’s devices which occasionally require pulling the battery in order to get them to refresh their status to the hub. I’ve had the Fibaro up on the wall for roughly 45 days and haven’t needed to do anything to it other than the initial setup.

@keltymd I’ll have to checkout the HSM200, as it’d be nice to not have to replace a battery ever. :slight_smile:

(Matt) #16

I have 6 of them now they work great and are extremely fast to react. to the point I dont put them on outside walls.


Which device handler do you use? Can you adjust update frequency, or update frequency base on temperature change?

Be nice to find a few power temp sensors, just be nice if price was cheaper.

I actually thew one of these up in my Attic as I wanted to see how hot it was getting.
Z-Wave Motion Detector w/ Temperature Sensor

It surprisingly updates pretty well, I don’t need a play by play in temperature increase, but it seems to give an update if the temp changes by 3-4 Degrees. Which I’ve seen give between 10-19 updates in a day, depending on the weather.I’ve watched it climb from 66 degrees to 95 and back down in 24 hours. Pretty neat to check the night before Attic temp.

(Matt) #18

I use this one

(Collisionc) #19

Sorry for the late reply, this is the one I have been using:

As an update for the Fibaro, still rock solid. I replaced all my temperature sensors with it.

(victor) #20

Does it work on ST? Fully functional?
Really interested then