If there’s one thing that I’ve learned from my use of Home Assistant it’s that data is addictive. In creating a strategy for whole home backup power, I selected the Shelly 3EM as a tool to track how much power the house draws. That provided a solid information to help in choosing a generator. It also started me down a path with inexpensive Shelly sensors.
When I later added a generator inlet to our garage, I opted for the newer Shelly Pro EM 50A. The new “Pro” models supports three kinds of connectivity; Wi-Fi, BT and Ethernet.
Both the current sensors are integrated into Home Assistant. Since HA has built-in energy analysis, this took almost no effort to setup. The current sensor for the house is how I track our load in real-time, and our usage over time. Load tracking is especially important when we are running on generator during an extended power outage.
Soft ice cream is no bueno
A while later Stella complained that the ice cream was not staying sufficiently frozen in our freezer. I took this an an opportunity to try the Shelly BLU H&T ZB sensor. For around $20, this is a little device that measures temperature and humidity. It’s battery operated and small enough to just live in the freezer. Connectivity is by way of Bluetooth Low Energy and/or Zigbee.
This sensor allowed me to track the state of the freezer compartment. I didn’t have to trust the fridge to hold it’s setting. I had independent verification.
At the time I didn’t have a Zigbee gateway in the house, so I opted for a Shelly BLU Gateway. This little dongle, plugged into a USB power supply, bridges BLE devices onto our Wi-Fi network. It has a range of 30m indoors, so it can handle any BLE devices in the house.
While connectivity has not been an issue, the BLE gateway is mildly annoying. It has a bright status LED that cannot be disabled. At night, in an otherwise dark room, it’s oppressively bright. Such lights really don’t convey any information beyond showing that it’s powered-up. I’d really like to Shelly to make it software controlled, like the status lights in Unifi APs.
Hot Times
Back in 2023 I replaced the Wi-Fi access point in the house. Stella preferred the new AP to be completely hidden, which meant locating it in the attic above the central hallway. The attic not climate controlled. It gets hot. But how hot?
At the time, I used one of the Netatmo indoor modules to get a measure of the attic temperature over the course of a week in the summer.
From that exercise I learned that it can get to at least 121F, which was within the normal operating range for the Ubiquiti U6+ AP.
I didn’t want to leave the Netatmo module in the attic for the long term, so I added another Shelly BLU H&T ZB sensor in the attic. They come with a patch of 3M 9448A double-sided adhesive. It was a simple matter to stick it to the side of a rafter.
I also installed a smart attic fan in one of the gable vents, to ensure adequate air flow through that often sweltering space.
Hot Outside
When the Netatmo outdoor module recently became suspect I added another Shelly BLU H&T ZB sensor. It provided a way to verify the correct operation of the Netatmo module.
Cool Water
There’s a small wine fridge in the kitchen that rarely sees any wine these days. It typically holds a few large bottles of soda and a cases of bottled water. It’s a Kenmore Elite model which hints at its age.
It’s failed once. I was able to determine that the problem was a faulty controller board. Since Kenmore parts are still available, I was able to repair it relatively affordably. Even so, another year down the path, the digits that should display the temperature have gone bad.
Stella commented that she thought the contents were not adequately cool. So, I added a fourth Shelly BLU H&T ZB sensor in there. From this I learned that the wine fridge is holding around 60F. About right for red wine, but could be colder for water & soda.
Shelly vs Home Assistant
Shelly has its own home automation application. I use the Shelly app on my phone (pictured) to manage the devices. However, since the current sensors integrate with Home Assistant so readily, I haven’t had much need to tinker with the Shelly automation tools.
Close
At present we have seven Shelly devices on the property; (2) Current sensors, the BLU gateway and (4) H&T sensors. They were inexpensive, easy to setup, and they work well. Further, they feed my data habit. Knowing is always better than guessing. One day I may make the effort to bring everything together into some kind of Home Assistant display. Not today.