What is the cheapest temperature monitor I can get?


#5

Is there anything about pricing for this yet? It does look interesting.


#6

Can you calibrate the SmartThings Button? Does someone have a picture of the device page and the user settings?


#7

Native driver


#8

I use a SmartThings button to monitor temperature in a bedroom. I also have a Monoprice Z-Wave motion sensor which has temperature monitoring in the living room. Below is a graph of the output from the sensors. The Monoprice is the blue line, and the button is the brownish line. The sensors are in different rooms, so some difference in reported temperature is expected (we have a wood burning stove in the living room).

We were traveling, so the house was cold (Nest thermostat "safety temperature"). You can see that the button has more frequent reporting, about every 1 degree F, or so, sometimes more often. The Monoprice is more granular. This is supposedly adjustable, perhaps using the Z-Wave parameter tool, but I haven't messed with it.

I find the button to be useful for controlling things as well as a pretty good temperature sensor. I hope this gives you some idea of its behavior. And yes, it's inexpensive.

I hope this helps with your decision.

-Scott


#9

Question how do you generate the graph data?


#10

This thread explains how to do that:


#11

@muir. Thank you. That helps a lot. The reporting of 1 degree change will work for me. I need to move from wireless tags to something localized.


#12

I was going to refer you to the visualization thread, but I was too slow to respond. Thanks @homeauto2112.

I'm using influxDB and Grafana, which are hosted on an Ubuntu machine. If you read through the thread you will see that there is some concern about the "InfluxDB Logger" app that makes all of this work. So far I've not had any issues, and the recent update which provides for asynchronous posting to the database may help alleviate the concerns.


#13

Thanks was hoping for something natively.... oh well....


#14

Thanks everyone. I Think I am going to get a couple Tradfri outlets and Xiaomi sensors and some Smartthing buttons and see what makes the most sense for my desires.


#15

Yesterday I replaced all of my Wireless Tags with SmartThings Buttons. The discovery was fast and painless and they all read within .3 of each other so there's been no calibration issues.

Update: While they do seem to update a temperature change around 1 degree, it's pretty tough to believe. I have one room where one button only updated twice in one 12 hour period. The delta as measured by my WirelessTags was 1.5 degrees. This might seem trivial, but I am struggling with it. Before I knew if the room was 72.5 within a few tenths of a degree. Now I may know it might be 71.2 or 72.9...just depends on when the update is sent.


#16

Any direct links? Just being lazy. Don't bother if you don't want to.


#17

We are here to help, Start with the first post, it has good info. Good luck.


#18

Is there any custom device handlers for the SmartThings button? I'd like to explore some options around a refresh cycle and the native driver doesn't support that. @mike.maxwell do these support Refresh capability?


#19

As an alternative, these wintop/zipato contact sensors report temperature, as well. I haven’t released the newest version of the driver with it (I’m waiting until I get the hardware offset implemented), but it does work.


#20

Sure, but for some silly reason I left it out, I'll add it in...


#21

Thank you sir!


#22

I just want to share some of my note when I started making my own Zigbee Environment sensor.

In regard to temperature, a lot of battery powered implementation can provide ambient temperature reading by using MCU internal temperature sensor. In battery powered sensors, most of the time, the MCU will be sleeping most of the time. Therefore, its internal temperature sensor reading will be close to the room ambient temperature where the sensor is placed.

The same MCU, when it is powered all the time, will be affected by "self heating". Unfortunately, this effect will be difficult to be calibrated if it were used to read ambient temperature. The offset will be dynamic depending on how busy the MCU is.

For some cases, where one need to read room temperature, the battery powered sensor is a "win-win" solution. Without additional cost the vendors can provide room temperature information. However, these devices will be limited by power consumption and side effect to avoid self heating.

If (or when) one have a need to stress out the reading on these devices either by configuring more frequent report or attribute queries, you may push to the limit of the device power limit as well as the open up the side effect of "self heating".

In Zigbee, the reporting capability of a sensor should be configurable up to a second resolution. However, I suggest that one want to be careful in a way that you do not want to be too aggressive so that you stress out the MCU.

Xiaomi temperature, humidity and pressure sensor is one of devices that has its own dedicated sensor for temperature reading. In this case, the design of the board and casing has much more influence on the temperature reading. It still uses battery. Therefore, it is still limited on the power consumption in the context of reading interval.

As a user/buyer, I hope that I can add to our knowledge base so that we can make a better buying decision.


#23

Well, I gave the SmartThings Button my best, but I have to return them. They are very difficult to calibrate, have a very long time (in minutes) before updating their temp and run anywhere from .8 to 1.2 degrees in difference from the current temperature (e.g. if my thermostat says 72, then a button could say 71.2 to 73.2 and that's with a lot of calibrating). In @muir graph above, which is showing 8 hour increments, there is a 3 degree delta at times. They are probably good for someone who wants a very general view of a temp, but I wouldn't recommend them for driving HVAC or whole house fans (my use cases).

I've had to go back to the WirelessTags. They are pretty cheap at $29 per 13bit version tag (plus a onetime $29 for the base station). They are accurate to .4F and you can set the update timer on them (2 minutes to 4 hours). Unfortunately I can only link them into HE via my ST hub and hub linker. This can add at least a 4 minute delay to reflect in HE. I believe someone has expressed interest in migrating the driver, but I'm sure it'll be a while.

I hope this helps.


#24

Here's my post in another thread about the WirelessTags.