ShellyH&T Gen3 Black | Wi-Fi and Bluetooth Smart Temperature & Humidity Sensor with Remote App Control & Monitoring | Smart Scenes | Notification Alerts | LCD Display | Free Data Storage Export

I have three of these. I just have them hit a local web server and report temperature and humidity. If you want something to poll, this isn't what you are looking for. They instead only connect to wifi and "push" data when the temperature or humidity changes. I suspect thats due to it running on AA batteries, and trying to get good battery life. As long as you are okay with that, then these work great.I'm using one to check outdoor temperature, and one to monitor the temperature of my dog house. I have the web server kick on a local power switch when it gets too cold, which kicks on a 200w panel heater (designed for chickens) and warms the dog house. Then I have it kick off when it gets too hot. The dog appreciates it when its super cold out. I have it kick on at 55 and off at 65. I wouldn't want to use it for too narrow of a temperature range though because I've seen it wait until 53 to turn on and it sometimes stays on a few degrees higher then 65.I prefer Shelley devices since they can be used without cloud involvement and they are good for hobbyists that find no reason to send sensor data all the way to a data center just so local devices can then reach back out to the data center to act upon the data. When you have everything working locally, response times are in the millisecond range instead of the second range (which can grow to the minutes range during high usage).

I am a software developer. I spent a lot of time reviewing different devices, interfaces and their specifications. I wrote software to manage this device, including RPC, Bluetooth and MQTT. I am also very experienced in the dynamics of environmental monitoring for residential and commercial buildings.In my opinion this is an excellent humidity and temperature monitor at a low cost for home automation. The interfaces are well documented, easy to work with and there are numerous open-source implementations and libraries available.If you are a non-developer or a home automation user, this device will monitor humidity and temperature and perform well.I have read comments regarding long times to report changes. Temperature and humidity do not change rapidly in normal residential or commercial environments. If you require fast change detection, you are designing for a problem this device is not intended for. This device reports on wakeup every six minutes. The reason is to save battery life. That is sufficient in normal environments.If you require fast response times, select a different type of device that is plugged into a power source and reports continuously. The device will need to support rapid temperature and humidity changes and those types of instruments are much more expensive. The big issue is accuracy when detecting changes. It does no good to use a cheap device that reports every 5 seconds if the changes are only +-20% accurate. Accuracy requires either time or money.

Seems to work well, though setup was more challenging than anticipated.

Pros: compact design, beautiful e ink screen.Cons: Dropped WiFi connection overnight. Uses 4 AA batteries. Reset button is impossible to reach without dismantling device. Home assistant compatible is a plus but it doesn’t really work. Returning this

Set up was tough. First you connect to its own wifi signal that it puts out to set it up it's parameters. It shows a list of available wifis to connect to, set up static IP etc .. Then it connects to your network wifi and your all done, however I couldn't get it to connect to my wifi. Time after time it simply would not grab. Finally I manually entered my wifi ssid instead of selecting from a drop down list and it took. It's been running for a few weeks flawless and solid.

I was looking for a humidity sensor with the following features:- WiFi ready, no need for a hub - highly desirable- No batteries for main power - absolute requirement- Product from a main home automation brand - high desirableOK - Plus on all of those. Now for the bad.Basic functionality in measuring RH was assumed. The intent was to poll three of these devices distributed in a 2300sf home to automate control of a dehumidifier more accurately than my current "not-smart" humidistat, and allow for some additional operational rules. The bottom line is that I have - three - of these Shelly devices, and they simply do not respond to humidity changes as tested against four other ("not-smart") hygrometers by another brand that I have used for several years. The Shelly H&Ts also do not track the hygrostat readout on my dehumidifier control, which tracks consistently with my other hygrometers.I have not observed the behavior long enough to confirm the problem, but from what I've seen is that there is a multi-hour (5, 6, more?) lag in the response of the hygrometer - which makes it pretty much useless for anything other than multi-day trends (maybe?). In my dehumidifier setup, the range of humidity being controlled is very narrow, with 1% RH changes typically happening within 10-20 minutes of operation of the dehumidifier. I don't want to dehumidify below the maximum tolerable humidity level (~62-65%) for power efficiency reasons, so when this threshold is reached I NEED TO KNOW IT IMMEDIATELY - otherwise it costs $$ and wasted power/resources!! Every 1% of RH below 60% costs me over 30 minutes of operation of a 700W dehumidifier.Other problems:- The mounting foot is a joke as implemented. Impossible to install without applying gargantuan, plastic destroying force.- Yeah OK, it only works on 2.4GHz wifi. No biggie - but it would be nice to know that they also DON'T WORK RELIABLY ON DUAL BAND wifi channels *in the setup manual*, rather than through a random google search. You'll want to set up a dedicated SSID with a profile that only uses the 2.4GHz radio, if you have wifi hardware that supports this.More problems:- Reset button needs to be accessible outside the case - like, really, what were you thinking?!- The instructions give no hint as to what is needed for the bluetooth setup, which is the only way I was able to register the devices with the Shelly app. There is a hint in the Shelly app about "device needs a single button push" for the bluetooth connection to complete. ...Since there's a single button on the device, then well, OK, I guess it's more-or-less obvious that one should try pushing the reset button? Maybe? There is no mention in the instructions anywhere that the "reset" button multiplexes as a bluetooth registration button. I mean - I write better idiot-proof instructions for the engineers in my workplace than these people are writing for the general public.