There's also Jason Griffey's Measure the Future project --
http://jasongriffey.net/mtf/. The project uses OpenCV with optical sensors
(again, not cameras) on networked Raspberry Pis. The repo hasn't been
updated since 2018 -- https://github.com/MeasureTheFuture

On Thu, Jul 9, 2020 at 1:57 PM Kun Lin <[log in to unmask]> wrote:

> It seems like it is a device sensing the existence of wifi or Bluetooth
> device in the area. I do currently have the capacity to get number of
> device association via building’s wifi access points as I assume student’s
> phone is most likely already configure to connect to college’s wifi
> network.  I will be looking more into entry/exit sensor for a more precise
> head count.
>
> Thanks
> Kun
>
> From: Monica Maceli
> Sent: Thursday, July 9, 2020 10:39 AM
> To: [log in to unmask]
> Subject: Re: [CODE4LIB] Anyone attempted to use Raspberry Pi w/camera
> tomonitor building capacity?
>
> I found the example I mentioned in case anyone is interested in the future,
> turns out it was a UCSD student project that they have now turned into a
> company -  https://waitz.io/  Currently, it looks like it is used in
> McGill
> and UCSD libraries and maybe others? They have done some product
> development on it, but under the hood each device is just a raspberry pi, I
> believe.
>
> They have a fancier algorithm for getting more accuracy, but I am just
> doing basic counting/deduping of any bluetooth-enabled devices in range of
> the Pi and then dumping the address data and just retaining the count for
> privacy purposes. So just using the onboard bluetooth chip with the pybluez
> python library, no additional sensors necessary, can scan the environment
> and tell you there are X number of devices in range with bluetooth on. Run
> and observed repeatedly you can then get a sense of the space's
> baseline and changes over time.
>
> To do entrance/exit detection external sensors are needed (wired to a Pi or
> Arduino), e.g. using PIR motion sensor or ultrasonic range sensor similar
> to the approach in the article Tom posted ->
> https://journal.code4lib.org/articles/12947 This is very straightforward
> if
> there is a dedicated entrance and exit. If it's bi-directional foot traffic
> you'd need a set of sensors to determine direction, e.g. in a meeting room
> to be able to say there have been 10 entrances and 5 exits so let's assume
> about 5 people inside. You could also get very fine-grained and use
> pressure sensors on each seat to tell if it's occupied or not (places like
> We Work do this).
>
> Kun - if you'd like to discuss further feel free to email me directly my
> contact info is in my signature, always happy to talk about sensor stuff!
>
> Best,
>
> Monica Maceli, Ph.D.
> Associate Professor
> Pratt Institute | School of Information
> 144 W 14th St, 6th Floor, New York, NY, 10011-7301
> www.monicamaceli.com | [log in to unmask]
>
>
> On Thu, Jul 9, 2020 at 12:32 PM Kun Lin <[log in to unmask]> wrote:
>
> > Hi Monica
> > Could you let me know what kind of sensor you are using? The bluetooth
> > scanner, are you referring to scanning for bluetooth device or it's a
> > bluetooth connection to your computer?
> >
> > Thanks
> > Kun
> >
> > On Thu, Jul 9, 2020 at 7:54 AM Monica Maceli <[log in to unmask]> wrote:
> >
> > > Hi all,
> > >
> > > I have been experimenting with entrance/exit sensors (pir and/or
> > > ultrasonic) combined with a Bluetooth scanner running on Pis to
> calculate
> > > relative space crowdedness for our campus.  Data is sent over wifi via
> > MQTT
> > > to a cloud Influxdb database w/ Grafana for data dashboard and
> alerting.
> > I
> > > don't have published code currently but I'd be happy to share and work
> > with
> > > others on this.
> > >
> > > I too felt that the cameras, while doable and probably more accurate,
> > would
> > > introduce too many privacy concerns.
> > >
> > > I got the Bluetooth idea from a project I heard about awhile ago, but I
> > > can't remember the original creator (I think a librarian had these
> placed
> > > in a library and a Redditor found a Pi and posted a "what is this
> thing?"
> > > post). Does this ring any bells?
> > >
> > > Best,
> > >
> > > Monica Maceli, Ph.D.
> > > Associate Professor
> > > Pratt Institute | School of Information
> > > 144 W 14th St, 6th Floor, New York, NY, 10011-7301
> > > www.monicamaceli.com | [log in to unmask]
> > >
> > >
> > > On Wed, Jul 8, 2020 at 8:57 PM Tom Keays <[log in to unmask]> wrote:
> > >
> > > > There was this write up from 2017 in the C4L Journal. Not cameras,
> but
> > > > other kinds of sensors that didn't trigger any privacy concerns.
> > > >
> > > > https://journal.code4lib.org/articles/12947
> > > >
> > > > On Wed, Jul 8, 2020 at 1:20 PM Goben, Abigail H <[log in to unmask]>
> > wrote:
> > > >
> > > > > I think Griffey did
> > > http://jasongriffey.net/mtf/homepage/feed/index.html
> > > > >
> > > > >
> > > > > --
> > > > > Abigail H. Goben, MLS
> > > > > [log in to unmask]
> > > > >
> > > > > -----Original Message-----
> > > > > From: Code for Libraries <[log in to unmask]> On Behalf Of
> Kun
> > > Lin
> > > > > Sent: Wednesday, July 8, 2020 12:02 PM
> > > > > To: [log in to unmask]
> > > > > Subject: [CODE4LIB] Anyone attempted to use Raspberry Pi w/camera
> to
> > > > > monitor building capacity?
> > > > >
> > > > > Anyone attempted to use Raspberry Pi w/camera to monitor building
> > > > > capacity? Any good resources on how to do that?
> > > > > Thanks
> > > > > Kun
> > > > >
> > > >
> > >
> >
>