There was a time when I wanted the lights to turn off automatically as I left home and the living-room light to come on when I returned. If sensors could tell whether someone was leaving or arriving, nobody would have to press a button.
To try it, I bought a ThingsOne MPP03 open/close sensor for the inner entryway door. I also placed ThingsOne MTP03 motion sensors near the front door and the inner door. I wanted to compare the timing of door events and nearby movement.
I only wanted to determine whether the house was being left empty. Looking back, I bought quite a few sensors for that one idea.
I keep a separate, updated record of the models and devices I have used. · MPP03 product page · MTP03 product page
Could the order of door events tell me?
I thought I could work out whether someone was leaving or coming home by combining the order of door events with detected movement.
A door opening on the entrance side followed by movement might suggest that someone had arrived. Events in the reverse order might mean someone was leaving. On paper, that sounded plausible.
Real family routines were less predictable. Someone might step out briefly and come back, or one person might leave while others stayed home. In the end, lights sometimes went out while another family member was still inside.
I described those experiments in “The Smarter I Made Our Smart Home, the More Often the Lights Went Out”. Now I use a small smart button by the entrance to turn all the lights off or switch the living-room light on.
I stopped using that presence-detection routine, but I still had the sensors.
I found more than an open/close sensor
When I bought the MPP03, I only expected it to tell me whether the inner door was open.
After adding it to SmartThings, I noticed readings for temperature, three-axis movement and vibration, alongside the door state. I was pleased to find so much more in a sensor bought for one simple purpose.
That made me wonder whether it really had to stay on the inner door. I began thinking about hinged doors, sliding doors, and even windows that open in a different way.
What about a tilt-and-turn window?
I was especially curious about tilt-and-turn windows.
These windows can swing inward like a door, or tilt inward at the top to allow ventilation. A conventional magnetic open/close sensor can already detect an open state once its two parts separate.
But what if the moving sash also changes its angle? Could three-axis readings help distinguish a tilted window from one that has swung fully open?
I have not installed the sensor on such a window to test it. The values would depend on the sensor's orientation, and I would also need to check whether SmartThings exposes those readings as usable routine conditions.
Still, it was fun to start with an inner-door sensor and end up thinking about the mechanics of a window.
Trying vibration to detect the door's movement
Once the sensor was installed, I noticed something else: someone in the family regularly left the inner door partly open.
At first, I thought of sending everyone a notification when the door had been left open. Then I wondered whether someone who had already walked away would really go back just because an alert appeared. I doubted it.
So I tried something different: rather than relying only on the open/close state, could I use vibration to detect the moment the door moved? I built a SmartThings routine using the vibration event and tried it out.
It did not behave consistently. Sometimes I opened the door and no vibration was detected. Other times a passing knock on the door triggered the sensor.
I could not reliably distinguish an actual opening or closing motion from an accidental impact. After a few attempts, I gave up on that routine.
I still wonder where vibration sensing might be useful. Could it detect a window shaking in the wind? How would it respond if attached to another object? Those are ideas I have not tested yet.
Could a motion sensor switch off the bathroom light?
I also thought about reusing the motion sensors bought for the entrance.
Sometimes my child left the bathroom without turning off the light. I considered installing a motion sensor there and switching the light off after a period with no movement.
But someone might be sitting still, or the sensor might miss a movement. It would be awkward for the light to go out while someone was still inside.
In the end, I did not even try that bathroom routine.
The MTP03 motion sensor ended up inside a drawer
So where did the MTP03 motion sensor bought for the entrance end up?
One of them now sits inside a drawer. When it detects movement as the drawer opens, SmartThings sends a notification saying “The drawer was opened.”
It does not directly measure whether the drawer is open or closed. I use the detected movement as a trigger for the notification.
A sensor bought to work out whether my family was coming or going now lives inside a drawer. That was not a use I had imagined when buying it.
At first I only wanted to know whether a door had opened and someone was arriving. But connecting the sensor revealed temperature, movement and vibration readings, and soon I was thinking about windows, drawers and other corners of the home.
Some routines were tried and abandoned. Other ideas are still just ideas. Every so often, I look around the house and wonder again:
“Where else could I put this sensor?”