
Show HN: I built a simple monitoring dashboard app for my life - justinlloyd
https://www.linkedin.com/pulse/weekend-side-project-justin-lloyd/
======
t_von_doom
Could you tell me a bit more about how your beacons work? I’d love to do
something similar tracking where/how I spend time around the house

~~~
justinlloyd
For the phones I use a combination of WiFi access point connection on my
Ubiquiti APs in the home, along with a small swarm of strategically placed
Bluetooth low-energy beacons around the home. A beacon in the drawer where we
keep the wallets, one by the coffee machine where there is a charging cable,
one by each nightstand, one in each bathroom, one by the kitchen computer, one
on the dining table, one at each desk in the respective home offices, and so
forth. I can query the Unifi API to determine which AP the phone is attached
to to get a coarse "Justin's phone is attached to the dining room AP." The
phones roam from AP to AP correctly so long as you dial down the power on the
AP so it only has a 3m or 5m range. Multiple APs in the house let you roam
easily and give good signal no matter where you are. I also query the beacons
at the phone's location to determine a more precise pinpoint.

For the wallets I use passive RFID tags (sourced from Aliexpress) and a couple
of wide and narrow RFID sensor stations, which either run over PoE (only have
two of that model) or are powered by a wall wart and connect to the WiFi and
they can be easily polled. "Your wallet is in the dining room" gives me the
wide range -- around 7m radius in real world conditions -- and multiple wide
range RFID sensors can then be queried and the positions triangulated (though
not entirely accurately) based on response.

The narrow range RFID sensors are strategically placed and cover about 18"
(45cm) radius. That gives me a more granular "your wallet isn't where it is
meant to be" report but it does give me "Your wallet is in the 'going out the
door, take these items with you' drawer" to make sure the wallets are put back
after usage.

For the pets I use a device known as a Loc8tor (British company I think) that
is attached to the collars, essentially active RFID (not quite, but that
description will do for this discussion), and several custom built sensor
location hubs.

For the tracking I took a lot of ideas from supply chain management and retail
environment solutions. Many years ago I worked on a "Big Brother" project for
a high end shopping mall that could do all sorts of scary tracking of phones
long before smart phones were a thing, that fortunately never launched. Now I
look back on that, I shudder at the implications. I also worked on a project
for the hospitality industry that can accurately track a guest's RFID tag worn
on a lanyard or a wrist strap as they move about a facility.

There's a lot of things I would change if I were doing this over again, or
spending any kind of time on it beyond a four day weekend. I would also not
use active RFID at all and just go fully passive. And I am not even sure I
would use BLE beacons for phone tracking, instead perhaps opting for more WiFi
APs to cover smaller areas. You can dial down the power to an AP so it would
serve the exact same purpose and Unifi make some wall mounted APs that are
very nice. That said, it would require a lot more cable runs in the home to do
that, that I am not willing to undertake.

If all you want is a heat map, and you have multiple WiFi APs, depending on
the brand of access point, you can easily track your phone as it hops from AP
to AP. Some of the research in how the WiFi radios of an access point respond
to a person being in proximity to them (a few metres) could also be deployed
for just simply tracking people.

The WiFi AP roaming and tracking is already a thing built-in to most
enterprise devices. The WiFi of the company where you work already knows where
you are, with reasonable certainty, and they know precisely how long you spent
in the bathroom and pretty much you're reading in there. The only thing I
really did different was "Weasley Clock" the phone tracking in to an easily
read smart home dashboard.

