I'm a big fan of what Apple has done with HomeKit, allowing you to purchase lots of different products from different manufacturers which can all work together to make your home smarter. Using an app on your iPhone or Apple Watch, or just by using your voice with Siri, you can easily turn lights and other devices on or off. One of the most powerful uses of HomeKit is automation so that events can occur without you having to do anything. For example, the lights on my front porch will automatically go on at sunset, so even if I come home after dark the front of my house isn't dark. And those same lights automatically go off at sunrise. Elgato recently sent me a free review unit of the Eve Motion, a HomeKit-compatible motion detector. It is a powerful addition to any HomeKit environment, although depending upon the size and layout of your house, it does suffer from one shortcoming which I mentioned last week when I reviewed the Eve Degree; it relies on Bluetooth, not Wi-Fi.
The Eve Motion is a small white device. It is not as small and sleek as the Eve Degree, so it is something that you and others will notice when it sits on a table. It is 3.15" x 3.15" and and about 1.25" deep. It is powered by a pair of (included) AA batteries. It can work indoors or outdoors.
The front of the device has a small window which can detect motion. Elgato suggests that you place the unit about 1-2 meters above the ground (about 3 to 6.5 feet). At 6.5 feet, the Eve Motion can detect motion for up to 30 feet across a 120º field of view. The back of the device has a hole that you can use to hang it on a nail on the wall.
You can adjust the sensitivity to low, medium or high, depending upon how much motion you want for the Eve Motion to be triggered.
The front of the device has a small red LED light behind the white plastic. You normally don't see it at all, but you can configure the Eve Motion so that the LED blinks every time motion is detected. I just found that to be annoying and quickly turned it off, but it might be useful in some situations to confirm that motion is indeed being detected.
Automation when motion is detected
The most common way that you are likely to use an Eve Motion is to cause a certain action to occur when motion is detected. For now, HomeKit automation is limited to other HomeKit devices; for example, I do not believe it is possible to send a text message to someone when motion is detected, which would allow the Eve Motion to work as a sort of a burglar detector when you are away from home. A perfect use of the Eve Motion is to turn on a light when you enter a room.
For example, I placed the Eve Motion in my TV Room and created a rule that turns on the lights to 100% brightness when motion is detected. That way, the lights come on automatically when anyone enters the room. Fortunately, HomeKit is sophisticated enough that you can customize this rule based upon conditions. For example, in a TV Room you wouldn't want the light to go up to 100% every time motion is detected, because you might have the lights turned down low as you are watching a movie and you wouldn't not want the lights to turn up just because you stretched your arms.
The solution is to add a condition to a rule. Conditions can either be time-based (it must be after or before or between a certain time of day) or value based (other HomeKit devices must be in a certain state). In this first example, I set the trigger to be any motion detected by the Eve Motion, and I set the condition to be that the lights in the TV room are set to off. That way, if the lights are already on and dimmed, then this rule won't do anything.
What if you like to watch TV in the complete dark? The above example won't work because the Eve Motion will sense motion in the dark and turn the lights on. You can account for this in the settings for the Eve Motion where you can adjust the duration to last from as little as 5 seconds to as much as 15 hours. Thus, if motion is detected and you have this set for three hours, the Eve Motion won't register motion again for another three hours.
By adjusting factors such as duration and conditions, you can create pretty sophisticated rules for automation. For example, if motion is detected in a room, you can make the lights turn on, but then go off after no motion is detected for a specific period of time. Or you can create a rule that says that when motion is detected, turn on a fan, but only during certain hours of the day, and only if the temperature is above a certain value. Or you can turn off the lights in a room if no motion has been detected after a certain period of time.
Log of values
In addition to using the results from an Eve Motion to trigger other HomeKit devices, such as turning on lights, another feature of the Eve Motion is that it creates a log of whenever motion is detected. You can view this on a graph, with bars indicating when motion was detected, or you can view a log of all values.
For example, in the second picture below, I can see that motion was detected at 10:58 p.m., and then no additional motion was detected until the next day at 8:47 a.m. Thus, if it useful to you to know when motion occurs place in an area — did a child leave a bedroom to go to the bathroom in the middle of the night; did a person make a late-night visit to the kitchen for a snack; is there any motion in your living room while you and your family are out of town — the Eve Motion can help to provide an answer.
The only real critique that I have of the Eve Motion is the same critique that I had last week when I reviewed the Eve Degree. Because the Eve Motion uses Bluetooth 4.0 to communicate, the Eve Motion needs to be reasonably close to a HomeKit hub to work. That hub has Wi-Fi and can communicate with other devices. In my house, the only HomeKit hub that I have is an Apple TV. When I originally tested the Eve Motion as a motion detector in my living room, I found that the room was too far away from my Apple TV and thus wouldn't cause lights to turn on and off. On the other hand, when I put the Eve Motion in the same room as my Apple TV, it worked perfectly all of the time.
An Apple HomePod or an extra iPad that you are not using can also act as a HomeKit hub, so if you want to put an Eve Motion in the same room as a HomePod, that should work fine. (I don't own a HomePod so I couldn't test this.) Another solution that I noted last week was to use a Bluetooth range extender, such as the Eve Extend first announced by Elgato back in January 2017, but apparently Apple hasn't yet approved of the use of these extenders in HomeKit and thus the Eve Extend is not yet for sale.
In the interim, I see a post on the Elgato website saying that you can use a second Apple TV to extend range, as long as it is an Apple TV 4th generation or newer. But those devices cost $149 new, and even a refurbished model is $129.
Depending upon the size and layout of your home, this might not be a problem at all for you. But for me, the limitations of the range of Bluetooth 4.0 — about 200 feet with no interference, and less than that depending upon walls and other interference — prevented me from using the Eve Motion in many of the places in my house where I might want to use it.
If you want to use motion to trigger HomeKit events such as turning lights or other devices on or off, the Eve Motion works great and I can recommend it — but only if you will be using it someplace that is within the range of a HomeKit hub.