Nigel Ramsay

Software Engineer from Wellington, New Zealand

A temperature and humidity sensor for NZ$20

06 August 2018

If you need a cheap way to measure temperature and humidity at home, then this device (Sonoff S22) is worth considering. I have recently purchased and installed 5 of these at home, and would recommend them to others.

As you can see, the device comes with a temperature probe. I’ve plugged mine into various sockets around the house.

As you may have noticed from the photo, the temperature/humidity sensing is the secondary function — with the primary function being a remotely operated switch. If you look closely, it’s also a handy international adapter, with support for American and European style plugs.

Reading the temperature and humidity

There is an app called “eWeLink” that you use for checking the temperature and humidity, as well as operating the switch. It’s available for both iOS and Android.

As you can see, the temperature and humidity are displayed near the top. If you have the device plugged into a heater (or similar), you can set this to some on at a certain low temperature, and then switch off once a warm temperature is reached.

I‘ve found the temperature readings to appear accurate — we have some other temperature sensing devices nearby and they seem to agree.

Other notes

The device supports both Google Home and Amazon Alexa ecosystems. I have used it successfully with Google Home to “turn off all the lights”, but it seems to be unable to “tell me” the temperature at this stage.

I make no commission on anything on this post — I’ve just a happy customer willing to share a useful product.