a lot of people who live in a smart home would probably agree that automated lights are some
of the most useful and regularly used automations that they have when I talk about automated lights
I mean those that turn on and off automatically at the right color temperature and brightness when
you need them to using your voice or even worse an app on your phone to turn on and off your lights
does not make them smart it's just an inconvenient switch the most obvious way to automatically turn
on your lights when you need them to is to use a little motion sensor like this these devices
detect motion really quickly and I use them all over my house to trigger lights when someone walks
into a room or up to my stairs I also use them to pause my Robot vacuum cleaner if someone walks
into a room whilst it's cleaning which stops it from barreling down on me as I'm walking up
to the fridge to get a snack but those of us who have used motion sensors to activate lights will
eventually realize that they are utterly useless knowing if a person is still in a room if they're
barely moving we've all probably been sitting in a room at a desk or watching TV only to have the
light switch off because the motion senses haven't detected you for a while so you end up frantically
waving your arms around trying to get them to switch back on well there's now a new Gadget in
town that solves this problem this is an acara fp1 presence detection sensor and it uses millimeter
radar waves which can detect very small amounts of movement to accurately know if there's someone in
the room or not I've been using these for about a month now and I'm really impressed at how accurate
they are detecting if a room is occupied or not but whilst they accurately detect if a room is
occupied or not they take a bit of time to figure that out in my testing it can take two seconds or
more before the fp1 changes its state to detected compared with the motion sensor's almost instant
response this delay is pretty noticeable if you're relying on the fp1 to turn on the lights
and I find it really annoying I want my lights to turn on instantly when I walk into a room not a
couple of seconds later I also want the lights to stay on whilst I'm sitting at my desk working or
slobbing around on the sofa watching TV so I now use both of these sensors combined and in this
video I'm going to show you how I've hooked them up to a home assistant sensor group to accurately
and instantly detect if a room is occupied or not when I walk into my office the motion sensor gets
triggered which in turn sets the sensor group to presence detected as well and the sensor
group will stay in that state as long as either the motion sensor or the millimeter wave sensor
detects something once both sensors stop detecting something the sensor group switches back to clear
the lights now turn on instantly when I walk into the room they stay on for as long as I'm in there
and they turn off again pretty quickly once I leave the room let's take a look at how I set
this up in my home assistant configuration and how the automations now work foreign
is pretty hard to buy at the moment and it's not technically available outside of China I was lucky
enough to find mine on AliExpress for about 80 US dollars but they very quickly went out of stock
the fp1 is the first commercially available presence detector that I know of that uses
millimeter radar waves to map out what it can see it does this over and over again to see if the map
it made last time is different to what it can see this time and uses that to infer if something has
moved in the room because the radar waves are so tiny it can detect very small amounts of movement
like someone's chest rising and falling as they breathe or their hands as they type on a keyboard
now I'm no scientist and I don't know anything at all about millimeter radar waves there's no
guarantee that this sensor isn't radiating my testicles as we speak preventing me from ever
being able to have children but I do know that it's been really reliable at detecting whether
or not a room is occupied this particular sensor has the ability to detect presence from up to
five meters away and it has a 120 degree field of view horizontally and a 40 degree field of
view vertically like most motion sensors where you place them is really important these sensors can
detect very tiny amounts of motion so make sure that they're pointed away from anything that might
move and create a false positive like a curtain flapping in the wind a fan or a fish tank this
sensor works pretty much like any other zigbee sensor and I was able to pair it with my home
assistant using zigbee to mqtt I'm told it will also work with Zha as of the 2022.7 home assistant
update once you've added it to home assistant you'll see the entities and controls that this
device exposes the one we're most interested in is the presence detection entity which works
almost the same as a normal motion sensor I've got this normal acara PIR motion sensor in my
office as well and we're now going to add this and the fp1 together into a home Assistant Group
to do this we're going to go to the settings menu in home assistant and then to the helpers area
create a new Helper and select the group Helper and then choose a binary sensor group a binary
sensor can be either on or off or detected and not detected which is why we're going to use this
for our purpose we can now give this group a name and add both the motion sensor and the millimeter
wave presence sensor to this group we're going to leave the all sensors toggle as it is which means
that the group sensor will switch on or detected when any one of these sensors is triggered if we
switch this toggle it would wait until all the sensors in the group detected presence before
the group would get set to on we can now save this group and then go back into it to change some more
of the advanced settings I like to change the type of the sensor to occupancy which makes the icons
and the values appear correctly in home assistant I'd also like to add it to the right area which
in this case is my office we can now use this sensor in some really simple automations but turn
the lights on when the group detects presence and off again when the group stops detecting presence
here is the automation that I use to turn the lights on in my office when the group
detects presence the automation is triggered when the group State goes from off to on that
is any of the sensors within the group have detected presence the PIR motion sensor that
I use also has a built-in light meter so in this condition I check to make sure that the
brightness is less than 100 Lux I only want the lights to turn on if it's dark in the office
a second condition checks to make sure that guest mode is Switched Off my office doubles as a spare
bedroom and before I had this check the spare room lights would randomly turn on in the middle of the
night if the guest got up to go to the bathroom or something they weren't pleased I actually did
a whole video on how to make your smart home guest friendly I've linked to that in the description
below and you should check it out after this video if all of those conditions pass then the
automation calls the light turn on service to turn on my office lights a similar automation Works in
Reverse to turn the lights off again when presence is no longer detected in my office the trigger for
this automation is almost exactly the same as the one in the previous automation except it
looks for the group to go from on to off that means that both the motion and fp1 sensors in
the group have stopped detecting presence we check for guest mode again and if everything
passes we use the light turn off service to turn off the office lights for good measure I
also stop any music that is playing on my office speakers by using the media player stop service
these sensors are useful for more than just lights too if you have Smart thermostats you could easily
create very similar automations that turn on and off the heating or cooling based on whether or not
there are people in that room or you could use a combination of presence and time-based automations
to open your smart curtains or blinds when you first get into a room each day I now use these
present sense of groups to control my Robot vacuum cleaner too each day at 11 PM my vacuum cleaner is
scheduled to clean the kitchen but sometimes we've got people over or we're hanging out in
the kitchen late at night and we don't want the noisy robot to start cleaning around people's feet
to prevent this the automation checks whether or not the kitchen is occupied before it starts
cleaning if there's people in the kitchen then it waits patiently until the kitchen present
sensor group has been set to off for at least five minutes the kitchen present sensor group
is exactly the same as the one I created earlier for my office once we've all left the kitchen for
at least five minutes the robot trundles off and starts cleaning I have another automation that
gets triggered when someone comes back into the kitchen and triggers the present sensor
group if the robot vacuum cleaner happens to be cleaning then it will pause itself wherever it is
it will then once again wait patiently until the kitchen has been empty for at least five
minutes and after that it will start up again and resume cleaning so now you know how to combine a
PIR motion sensor and a millimeter wave presence sensor into a single group to get an instant but
accurate representation about whether or not a room is occupied I've actually taken it one step
further in my house and combined these two sensors with the es presence Bluetooth tracking sensors I
created in a previous video in that video I showed you how to track who is in what room of your house
and you can use that to trigger custom automations to set lighting music and climate controls to be
exactly what that person prefers if you've not seen that previous video you should go check it
out after this I'll put a link in the description below anyway I've combined those Bluetooth
tracking sensors with the motion and fp1 sensors inside my home assistant configuration.yaml file
I've created a binary template sensor which works very similarly to the group we created
earlier and it gets set to either on or off based on the states of a bunch of other sensors you can
see my office template sensor in my yaml here it checks a bunch of sensor States including my
mobile phone my partner's mobile phone and my fitness tracker to see if those are currently
located in my office it also checks to see if my office PIR motion sensor or fp1 sensor have
detected any presence if any of these conditions are true then it sets the template sensor to on
indicating that the office is occupied I've created these sensors for all over my house
and I now have a pretty reliable foundation for creating presence-based automations not just
when a room is occupied but I can also customize those automations based on who is in what room
the main downside to this whole thing is that you need to Jumble a bunch of different sensors
together to get the most performant and accurate results it would be great if someone could release
a multi-sensor that combined all of these into a single device it's definitely possible Lewis
from the everything smart home YouTube channel has gone ahead and soldered together a Frankenstein's
monster of a sensor that combines all of the things we just spoke about and more into a single
device unfortunately it involves a lot of coding soldering and 3D printing so it's not something
that's accessible to everyone I'm really hoping he starts selling them as I would sign up to buy a
bunch of them immediately you should go and check out his video it's really cool and I've linked to
it in the description below would you buy one of these multi-sensors if they were available let me
know in the comments below I'd love to hear where you would use it and what kind of automations
you'd create with it whilst you're down there why not click the Subscribe button I regularly release
videos like this about Smart Homes home automation and home assistant by clicking subscribe you
support the channel join the community and then together we can make your home smarter