 |
 |
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 > > > > > > > > > > > > > > >