Beam sensor?

Any beam sensors available? I'm trying to come up with something that can track direction of movement, for entering and exiting rooms. Since motion sensors don't have "motion" vs "stop motion" (that is, polling and retrigger rates are too low), I'm thinking two beam sensors on each door - one each for inside and outside the doorway - would do the trick , if it works like a contact sensor.

If not beam sensors, anyone else come up with a solution?

I use something similar to this for my front door

Connected to a fibaro door sensors



@ogiewon would be disappointed if I didn't point out that if you want to keep this really cheap, this sensor is a perfect device to pair with Hubduino, since it requires main's power. I have something similar working with an RF receiver to receive commands from the HomeLink garage door opener in my car.


I've seen people taking the iris motion sensor and putting a "cone" around it or tube so it's directional.

How fast do you need the motion active/inactive to toggle?

The Iris motion sensors that @pgiesenhagen mentioned reset to inactive within like 10-20 seconds and the battery life is quite good.

For accurately tracking direction of travel, it would need to be at most a second or two, as the amount of time for someone to reverse direction. ("At most" meaning "to be accurate" - at some point, I'll need something, whether it meets my "at most" requirements or not.)

I'm thinking an active sensor, since the downside of needing to be wired would apply to a motion sensor with a really low refresh rate.

But @pgiesenhagen's idea with a super fast motion sensor might be the best choice, since I'm not big on DIY (mostly for aesthetics). For now, just exploring the options.

So far as I know, 10 to 20 seconds is about normal for a motion sensor. I did see one the other day that would go down to 5, but not sure it would work on Hubitat, especially the configuration options (without writing the driver myself). I suspect finding the fasted motion sensor for Hubitat will be even more difficult than finding my options for a beam sensor. :stuck_out_tongue_winking_eye:

(I'm a little surprised there's not a "go-to" solution for this.)

Have you looked at laser trip beams?

Laser Tripwire Alarm: 9 Steps (with Pictures) Thats a DIY but there are probably commercial versions.

Might be worth looking through Google to see what options are out there.

My thoughts currently, as just thoughts rolling around in my head....

(Just to be clear, my solution needs to be aesthetically elegant. Just saying, since lot's of people put that second.)

So, my current thoughts are, aside from just using a network of motion sensors like a normal person, would be placing either an active beam sensor (laser or IR or whatever) or a wired fast-refresh motion sensor (with a "cone") at about chest height (on both sides of multiple entryways). Since an active sensor would need to wired for power, I'd want it as close to the ceiling as possible, and drop a wire from a DC adapter in the ceiling (and figure out how to get power to a DC adapter in the ceiling :wink: ).

If it's a DIY thing (which with a beam sensor seems the answer is "obviously"), I'm thinking I would also run a signal wire to it, rather than connecting the radio to it directly/closely together. However, I'm not completely opposed to cutting holes in the wall. But, as per aesthetics being a priority, it'd need to be covered, presumably with a plate (or door) to allow access for maintenance, and it'd need to be in a box (not that that's a big deal). That would be complicated by being in an entryway, of needing to get power through/around a door frame. But the advantage of putting stuff in the wall would be to remove height as a factor.

At this point, the laser pointer idea is most attractive to me, since the laser itself could easily be inserted into a door frame.

I know there's serious issues/complications I'm not thinking of, so would appreciate any thoughts - or someone telling me exactly what to do :grin:

Beam sensors to do occupancy based on direction of travel require 2 sets of sensors. Otherwise how do you know if a person is moving into or out of the space? That is why they are typically not used for this purpose in homes. If it was practical, that would be the way that everyone does it. This type of occupancy designation is only effective if the path of entry and exit is controlled and limited (ie a long hallway) where you are able to get two distinct events that are received far enough apart to be distinguishable but not too far apart where the person could have changed direction between the two. Typically this would not be done at the hub/server level but instead at the device level.
I did a lot of research on beam sensors a while ago to try and incorporate them into my ST setup and in the end, it was just never going to be accurate enough to make it worth the effort. Hubitat might be faster since it's local but I still don't think you're going to be able to process the events fast enough and concurrently enough to be able to keep the occupancy designation accurate for any length of time.
Think of this scenario, tow people walking into a room together. the sensors would have to be able to distinguish between the break in the beam for person 1 and person 2 and "know" that two people entered the room. That way, when 1 person left the lights would stay on since the room is still occupied. Also, what about someone entering and leaving the room simultaneously. Whatever is processing the events would have to concurrently add someone and remove someone from the room count.
And trying to do it with one sensor, is just going to be completely fraught with problems. The only place that I found using beam sensors to be practical is strictly for "quick activation". For example, having a beam sensor just outside your bathroom door to activate the lights so that by the time you got into the room, the lights would be on. It would reduce the delay in lights coming on when using a PIR motion sensor. But since HE is all local, hat time should be practically zero anyway, unless your sensor is delayed in reporting or your lights are delayed in coming on.

Hmmm... Good point.

Maybe with a DIY approach, I could get around that by connecting both beams (by wire) to a single radio controller unit?

... eh, then I'd need some way to tell which of the two beams is which. I'm sure rigging a radio controller to handle two inputs is doable, but if they aren't off-the-shelf, it'd be beyond me. And off-the-shelf might increase the cost beyond the value.

I don't see these as being often enough to not outweigh the advantages. I'd need to account for two people entering so it wouldn't be confused that the break between people isn't a person entering then exiting, then another unknown/unconnected event. As one person entering and one exiting at the same time, it'd need some maneuvering around for a doorway to even do it. For a hallway or larger entryway, I could see the automation code being able to handle two people passing and two people entering a doorway would be rather tricky - at best. Then again, it'd be rare to happen in a hallway exactly where the beam is at.

So, I acknowledge it would be far from perfect, and would need some fairly complex coding.

I'm thinking it'd be a good solution for garage parking, if we ever clear out enough room for an entire car. But agree there aren't many other applications for beams.

To answer your questions about sensors...

I can’t find anything commercial, so thinking outside the box, I wonder can you connect a garage door sensor kit to say, a konnected alarm panel?

I have no idea how those sensors connect, but I suspect it might be as easy as just hooking it up like any other sensor.

Garages would be a different story. If you have a single garage, if you have a break in the bean then you can assume a car is driving in...unless it is a person walking in. In that case, you would have to measure the length of time the beam was broken. If short, it would be ignored as a person. If long, then a car. However, I think you're overcomplicating things. If you are trying to have a light on in a garage, you can do so by the door being open or a PIR sensor would pick up a car very easily.

Offtopic, but this would have two functions. First, it could serve, at least to some degree, as a general house occupancy status. If the car is in the garage, then someone is either at the house or within walking distance. Or on vacation. Or picked up by friends. Still, it could serve as a "backup" as it were, for things like auto-unlocking the door or something to double-check for sounding a security alarm

edit: In line with that, if the car is in the garage, and someone attempts to open the garage from the outside, there's something wrong. Then if, for instance, someone then enters an invalid lock code, that'd be enough for an alarm. /edit

edit2: Thinking this through, since it'd be easy to drop something in front of beam sensor, trying to account for that within a security system would be overly complicated for the very limited benefit. /edit2

The bigger reason would be a parking-assist stop light system. Like this (random product and vendor as just the first one I found). edit: A true "stop light" would need multiple sensors, but I'm actually thinking more of a lighted "stop sign".

I'm pretty sure a parked car would not in fact be caught by a motion sensor. If it could only sense arrival and departure, then you're back to not being able to tell the difference between a person or car (except maybe if you could turn the sensitivity wayyyy down).

edit: And not actually know if the car is there or not, just whether it had arrived or departed, though I admit I have a beam sensor at the door of the garage.

I came up with something that works well to eliminate false alarms. I have a motion sensor and a beam sensor. The beam is DIYd into a dry contact sensor.

The motion sensor will detect motion (mostly people, is a PIR) first, so if that is active when the beam gets tripped, bingo, sound alarms. If only one of them get tripped, ignore, keep sleeping.