meross WiFi Thermometer- Smart Humidity Temperature Sensor with Alerts (Hub Required) for Baby Rooms, Greenhouses, Pets, Instruments, Collectibles

I bought one of these temperature probes and hubs a year ago but couldn’t work out how to get it to connect to my router but my New Year’s resolution was to get it to work or change ISP. After some messing about i discovered that you have to select the hub in WiFi first then go to the app and hold down the button on the hub, press twice then poke the sensor with a needle to get it to flash to show pairing then restart the Meross app. Hey presto, works fine albeit calibration a bit suspect but temp can be adjusted to suit actual location compared to probe in a bit of meat in my case since I use the monitors in my fridge and Coldroom to monitor from my iPhone.Although this is a cheap bit of kit it’s much cheaper than bespoke commercial options and probably has more longevity than commercial options which frequently stop working every time your OS gets updated or the supplier wants a maintenance contract. More importantly, the Meross software interfaces with iOS or Android using a ubiquitous app. So, in view of price and user forum in app, it’s a good bet long term.The other plus is that you can add tools, other Meross devices and get the sensor to push an alert to your iPhone without complicated server solutions.So for functionality 9.5/10 even though I haven’t explored the automation yet. At this price and range of options it’s a good bet if you have fridges or environments to monitor temperature and humidity and need an easy to use alert system which you or staff can monitor can monitor on a normal phone without complicated third party solutions.

Firstly the problems, you aren't here to read a 300 word review of loveliness just to get to the punchline.1) Batteries have been lasting 4 months maximum, despite whether i get well known branded ones or the cheapish £1 ones2) Doesn't seem to work below 6 degrees C despite the instructions saying it will work to 0The main problem with the low battery is you don't actually get a warning until the connection loss happens (on my 2 occasions anyway) you go out to its location thinking it just need a 'hub' reboot (this has happened a few times, but always expected with wifi stuff these days isn't it). Sometimes it has alerted me with a red battery symbol on the actual app, but then next time when i go into it the battery has disappeared. There is no battery state of charge in the app which is a let down really, it can sense temperature and humidity, surely another sensor on their sensing the battery voltage would be easy to do?As for the rest of the device and app, there are plenty of other reviews here going into more detail, but the accuracy, responsiveness and general easy of setup and use has been great. Sadly loses 2 stars because of the things above it. Don't suggest it can work at 0 degrees when it can't and battery life i can't explain, i don't use it in extreme conditions (despite testing the 0 degree thing) its normally in an environment which is between 16 and 30 degrees so should be perfect for the battery to live a healthy life.

Overall a handy device. I use a sensor to monitor the temperature in a greenhouse. The hub (which is required) is in the kitchen about 20 meters away and receives the signal fine.You can see current and historical temperature and humidity and can connect multiple sensors to a single hub.Using the app, you can setup Routines to control other Meross or IFTTT devices (note that IFTTT is not as 'free' as it used to be). You can also setup phone alerts (for when the sensor reading hits a specified level).To use the device/hub, you need to install the Meross app and create an account although there is no fee for the basic services (at the moment at least). I think this is an unnecessary complication for a device that could just sit on a WiFi network and allow me to access locally at least. Presumably it's an attempt to make the device more secure (assuming the Meross server doesn't get hacked ...).Installed the Alexa Skill and it seemed to link fine, but failed to detect the sensor.

Update - having owned two of these devices for some 4 months now, the second has now decided to go offline some 4 weeks after the first, flashing green and refusing to come out of this state regardless of following reset procedures, and the the hub is in the same room. Despite LED indicators all looking good I decided to order some new batteries and they are now working again. Devices work well but seem to have two potential issues - short battery life (will see how a new battery does) and difficulty in knowing that your connection loss is due to a fading battery.I already own other Meross smart devices (bulbs, smart plugs and previously, a smart radiator thermostat) and so deciding to purchase this device was made easier due to easier integration using the Meross app and other Meross devices. Unlike the other Meross devices this smart sensor doesn't seem to show up in the Google home app.The smart sensor requires a Meross hub which uses the Zigbee standard and reduces the power drain of this battery device compared to wifi. Setup was straightforward using the Meross app. Once setup temperatue and humidity were displayed and trended on the app. The temperature appears to be accurate when the unit is placed side by side with another smart heating thermostat. There is also a calibration feature within the app menu that lets you tweak the value.Also within the app menu for this sensor is an automation option. Selecting this allows you to set a temperature range with which to trigger a Meross smart device (smart plug in my case) on or off (tip - selecting within your range creates a 'tick' symbol and and triggers when the temperature is within, selecting either side outside the range triggers when the temperture is less than or greater than that range).For me this device has worked brilliantly allowing a simple mains fan to be turned on when the room temperature gets warm, and turned off when the temperature drops.Recommended if you have other Meross smart devices, I cannot comment on integration with others.