The key for me was the ability to extract strings from mqtt topics (msg.topic) with regex’s.

Eg. using node red’s Change node and jsonata expressions:

$match(topic, /binary_sensor.(cam_\w{5})_motion/).groups[0].$string()

That gives you ‘bacon’ in binary_sensor.cam_bacon_motion. Set msg.data.foo to that and the flow can be used for anything matching the regex. Moreover, you can use $.data.foo in the same change node to set other msg.*

It’s really powerful.

I want Home Assistant to quickly know when I arrive home, and waiting for my iPhone to connect to my Unifi wifi is too slow, too late, because I don’t blast my wifi APs at full-power to reach very far outside. When my iPhone is close to my mailbox would be a suitable trigger.

It would also be nice to track when I’m in the bedroom for more than 2 hours, after 10pm, to trigger “I have gone to sleep” automations.  Ditto for “It’s morning, and I have woken up” automations. These are easily buildable in Node Red.

Setup your iBeacon/beacon

First, setup & configure your iBeacon/beacon. Article: How-to for RadBeacon Dot beacons

Install the Home Assistant OwnTracks integration

Using the Home Assistant web-ui front-end, install the OwnTracks integration.

Configuration > Integrations > “+” icon, and search for “owntracks”.

Copy the instructions and especially the URL and “secret” it gives you and stash it somewhere safe.

“entity-id” in this article is the Home Assistant entity ID.

Setup the OwnTracks iOS app

Install the OwnTracks app from the Apple app store.

In the OwnTracks iOS app, follow the instructions just given by the Home Assistant OwnTracks integration to configure the app’s settings:

• Change the Mode to HTTP
• Create a TrackerID (two letters, like initials for your first & last name)
• Create a DeviceID that will appear in the entity-id
• For UserID, enter your first name, alias/username, or any name you want (it will also be part of the entity-id)
• Enable Authentication
• Leave Password empty, and enabled or disabled doesn’t matter
• For Secret encryption key enter the long string of characters that the Home Assistant OwnTracks integration gave you as encryption key  . This must match the Home Assistant OwnTracks integration  and is the shared key the iOS app and your Home Assistant backend will use to securely communicate region enter/leave events.

Create a region assigned to the beacon

In the OwnTracks app, create a region represented by your iBeacon/beacon:

• Tap “Regions” at the bottom of the main screen.
• On the Regions screen, tap the “+” icon in the top-right to create a new region.

A region in OwnTracks maps to a zone in Home Assistant.

In the region settings, give the region a name and add your beacon’s details:

For beacon-based regions (rather than GPS-based regions), the radius should be set to 0 (zero) per the docs. Paste the beacon’s UUID.  If you are only tracking on UUID, leave major & minor numbers empty. Else, enter the beacon’s major & minor numbers.

You can also track on UUID and major number (no minor number). It all just depends on your application. For example, some people organize their beacons by a single UUID for the whole museum, major number for a wing in the museum, and a minor number for an exhibit within a wing.

You can also have multiple beacons with the same UUID and major/minor numbers, and spread them around the house. This would be something like a super-region that covers the whole house. But then, why not use wifi-based presence?

NOTE: Some docs out there haven’t been updated and tell you to ensure share is enabled in the region’s settings. This setting has been removed in the latest version of OwnTracks iOS (May 2020). All regions are shared by default now.

Create a new zone for the region

Create a zone that matches the OwnTracks region to your Home Assistant configuration.yaml file:

zone:
  - name: Mailbox
    latitude: 47.4
    longitude: -100.1
    radius: 5

Optionally, configure the OwnTracks integration to process region enter/leave events only (ignore location/GPS updates):

owntracks:
  events_only: true

And restart Home Assistant.

Tracking when your iPhone enters the beacon’s region

In Home Assistant, the entity-id has the format:

device_tracker.<UserID>_<DeviceID>

I created a beacon named Mailbox and a Home Assistant zone also called Mailbox. The settings I used in the OwnTracks iOS app were donn for the UserID and dleeiphone for the DeviceID.

So, when I am close to the beacon located inside my mailbox, the entity device_tracker.donn_dleeiphone changes to state Mailbox.

Notice that the source_type is bluetooth_le (BLE), which makes it easy to find all beacon-based entities.

Additionally, a Home Assistant logbook entry is created:

And when I walk away from my mailbox, device_tracker.donn_dleeiphone changes to state home because I am too far from the mailbox but still at home.

Now I can trigger automations in Node Red using the state of that entity-id.

But… when leaving the house?

When I leave the house, I pass by the mailbox and I don’t want this to be interpreted as an arrival home. So there’s simple logic in a Node Red flow to check that I was away from home (aka not_home state), according to other entity-id’s, for at least 20 minutes before entry into the Mailbox region is considered an arrival home.

Latency/Reaction time

In practice, I’m seeing the state change from not_home to Mailbox in less than 10 seconds (sometimes less than 5 seconds). The change from Mailbox to home usually takes longer: more like 20-30 seconds. There may be a timeout in the app that waits before declaring the iPhone has left the region assigned to the beacon.

Beacons that move

The beacon itself can move, so the beacon has its own entity-id with a state value that will change to reflect the last-known location Home Assistant has for the beacon. For example, you can put a beacon in your backpack and watch its state change from home to work. Where the state values are names of zones you have created.

So if you named a beacon backpack, the entity-id would be device_tracker.beacon_backpack and the state of that entity would change from home to work zones (example).

The beacon is dumb. This is possible because your smartphone is close to the backpack beacon and OwnTracks is telling Home Assistant that it’s close to backpack with a GPS coordinate of X,Y (lat, long).  You can track where you parked your car in the same way.

In the OwnTracks app, beacons that change location should have their region settings set to a radius of -1 . See the docs.

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The goal is to use beacons for room presence with Home Assistant smarthome automation. I always have my iPhone with me, so tracking the phone will quickly locate me in a room or at the front door when I come home.

iBeacon is the protocol (packet format) the beacon will emit. Eddystone and AltBeacon are other protocols. Even though Apple defined iBeacon, any device, eg. Android, can listen to iBeacon packets. Beacon packets are emitted using Bluetooth Low Energy (BLE).

I chose RadBeacon’s “Dot” beacon over their “Chip” beacon because the Dot has a replaceable coin battery, CR2032 (a popular coin battery size).

Radius Networks sells two versions of the Dot: Non-configurable ($11) and Configurable ($14). Get the Configurable model.

Get the RadBeacon Dot working

Download the RadBeacon app from the Apple app store. Launch the app. The first screen will be an empty list of beacons because you haven’t discovered any beacons yet.

Turn on the Dot by clicking the top of it (lighting bolt symbol button) once. The GREEN led will flash once, indicating the Dot is ON.  To turn off the Dot, click the button once and the RED led will flash, indicating the Dot is OFF.

With the Dot ON, press and hold the button for about 5 seconds until the GREEN led flashes twice. This indicates the Dot is in CONFIGURABLE mode (config mode, for short).

Swipe down (pull down) on the app’s first screen to scan for nearby beacons that are in config mode.

Your new beacon will appear in the list with its name, model, version, id, and battery status. Tap the row for the beacon to see detail and config options.

(I’m not using any of the UUIDs in this article)

In the next screen, you can configure the beacon’s name, type/protocol (iBeacon, Eddystone, AltBeacon), UUID, major & minor numbers, advertising rate, and transmit power.

To extend battery life, I decided on an Advertising Rate of 1 time per second (1000ms, or 1Hz), the lowest setting. This should be quick enough for room presence applications. For Transmit Power, see below.

After you setup everything, tap “Actions” in the top-right of the screen and tap “Apply” in the actions menu.

If it asks to calibrate to the measured power, tap “Yes”. The app will ask for the Dot’s PIN, which by default is 00000000 (eight zeros).  Now the Dot is configured.

To determine a suitable Transmit Power, you can tap “Actions” in the top-right of the screen and then tap “Range” in the action menu.

This will run a utility that shows, in real-time, how close your iPhone is to the beacon in meters. “Immediate” means the phone is super-close to the beacon. “Unknown” means the phone doesn’t “see” the beacon and so is out-of-range. Play with different Transmit Power (measured in dBm) strengths and use the “Range” tool to tune the detection range to your liking.

You can copy-paste your Dot’s UUID from here to another app like OwnTracks:

If the Dot will be in an area where people could reconfig it: Tap “Actions” and then “Update PIN” to change the Dot’s default PIN, 00000000 (eight zeros), to a custom PIN. Save the PIN in your password manager, eg. LastPass. In reality, few will know what a beacon is and even fewer will want to reconfigure it. Most likely, someone will just steal it and play with it later, so maybe mount it high off the ground if you’re worried.

Click the Dot’s button to exit config mode (green led flashes once).  Config mode consumes a lot of battery, so exit config mode as soon as possible after you are done configuring your Dot. The Dot should automatically exit config mode after 30 minutes (not tested).

There was an academic project that estimated the battery life of the Dot. Title of the paper is “ARCTIC: An IoT-based System for Child Tracking in Day Care”.

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