True PRESENCE sensor


(Geoff) #1

I apologize if this has been discussed a thousand times - I found something similar in a discussion of virtual presence sensors, but not what I was really looking for.

Presence sensors are really ARRIVAL and DEPARTURE sensors, not PRESENCE/ABSENCE sensors. Are there any true PRESENCE sensors? A device that SmartThings checks every few minutes to see whether it’s within the range of a LAN or Bluetooth connection or within a geofence to know that it’s really nearby?


#2

What you describe actually is exactly how the SmartThings zigbee presence sensor (now called arrival sensor) works.

The arrival sensor checks in with the hub every 30 seconds, and after a certain number of check-ins are missed in a row the hub then marks it “away” until there is another check in.

So it’s actually not a barrier crossing device. It’s a “within barrier” device.

There are various issues that can cause problems with it, much discussed in the forums, but it is exactly the kind of device you’ve asked for.

Do you have one now, and if so, what kind of problems are you seeing?


(Geoff) #3

Thanks for the reply. Perhaps I’m being dense and missing something obvious. Right now I use my family’s iPhones as presence sensors. I have the doors lock, for example, when everyone leaves. But if one of my kids leaves his phone off until he gets to school, the phone never knows that it crosses the geofence and is listed as “present” until he returns home and leaves with his phone turned on. So the door never locks automatically. I can lock it manually, but I could do that without smartthings.


#4

The phones as presence sensors work differently than the SmartThings-branded zigbee arrival sensor, which is a $30 keyfob device that does not require a phone. You can buy it from the SHOP link at the top of this page.

The zigbee device doesn’t get turned off and on–as long as the battery is good, it’s on. And as I mentioned it is based on time between check ins, not barrier crossings.

So the theoretical device you asked about exists, and is sold by SmartThings. The problem is that it can be somewhat flaky depending on local WiFi interference. It works great for many people, but not all, and you can’t tell how it will do at your house until you try it.


#5

BTW, we solved this differently at our house. We have a lot of people who come and go, including home health aides, and they don’t all have smart phones nor do I want to give them all keyfob sensors. So we got a smart lock that automatically locks itself after two minutes. It has a keypad so a code Can be used to unlock it (like if you forget your phone), or the usual arrival detection can be used.

This has worked very well for us and was well worth the $200 investment.

The lock you have may already have this feature, it’s worth checking.

FWIW.


(Michael Hess) #6

I do this as well. I have a rule setup in RM to disarm the house when a valid code is entered in the front door lock. With bravenel’s help I was able to delay this with SHM so when the door opens there is a 15 second delay before a virtual switch triggers (or not) the alarm. I also use Life360, it’s WAY more reliable (still not perfect) for geofencing. My garage knows if my car is in or out and if I come home it will open the garage for me. Haven’t had a false open yet.

Locks and doors are all set to auto lock/close after 30 seconds/20 minutes respectively in case something does go wrong.

Kids (and wife) always forget their phones so I can’t expect that to activate anything whole house related, away mode will auto activate if everyone leaves, but I manually do it anyway because I’m paranoid.


(Geoff) #7

Thanks for all of the replies. My lock doesn’t have a keypad on the outside unfortunately. But it looks like the zigbee sensors will do what I want - I was trying to avoid the expense and duplication. Plus, my kids would NEVER leave the house without their phones, but I might have trouble getting them to remember to take their sensors. Maybe I can make a rule that says if the phones are all gone, then lock the doors. If they’re not, then check the zigbee for the person whose phone is home - if it’s gone, lock the doors.


(ActionTiles.com co-founder Terry @ActionTiles; GitHub: @cosmicpuppy) #8

Yah… I never understood the value of a smart lock without a keypad. It’s the most valuable feature to me. I can give out a code by voice, text message or whatever and don’t have to rely on any other technology to let people in or lock the door.

It also serves as an identifier of who has entered the house (i.e., each code is unique), easy to revoke codes from temporary visitors / workers, it can be used to disarm the alarm system, etc., etc…