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Presence Detection with BLE using monitor.sh

I have been running Home Assistant for a while. Things are going well. But I have had some issues with presence detection using the standard device_tracker component. Though I live in a small place, being in Tokyo, Home Assistant sometimes stops detecting phones if they are in an area of the apartment a little away from the Home Assistant server. This I suspect is due to the position of the Raspberry Pi and the building material.

Doing some research I came across a possible solution using multiple BLE devices. I have opted to use Monitor, a bash script solution.

This is a guide mostly for myself. I need to remember how it was setup. My approach has been to try and avoid rewriting my configuration and use most of my existing tracker_device automations.

Setup Mosquitto (MQTT) on your Home Assistant

I configured MQTT to use a username and password. This is all that is really needed to get things started. If MQTT is already setup. Skip this step.

Hardware

In addition to my Home Assistant server. I have:

  • Raspberry Pi Zero WH
  • Raspberry Pi 2 + Bluetooth dongle

 

Installation

OS

For the most part I followed the guide at Level1Techs.

Setup your Raspberry Pi Zero W(H)

  1. Download Raspbian
  2. Image Raspbian
  3. Mount the Boot Partition
  4. Create wpa_supplicant.conf with this config:
country=US

ctrl_interface=DIR=/var/run/wpa_supplicant GROUP=netdev

update_config=1

network={

ssid="Wireless Network Name"

psk="Wireless Network Password"

key_mgmt=WPA-PSK

}
  1. touch ssh
 touch ssh

Step 5 will enable ssh to your device.

Finding your new Pi on the network

If your network is small you can simply run:

arp -a

This will give you a list of devices currently connected to your network. So run this once before you power up the new Pi.

After you power up the Pi. Run the arp command again and see which new address appears in your list.

ssh into the new Pi using the standard username and password. Don't forget to change the password just as a matter of good security practice.

Packages / monitor

Update system and packages

Issue the follow commands

apt update && apt upgrade
apt dist-upgrade
apt install pi-bluetooth

Next reboot the device and login again once it's up.

Install git and Mosquitto
wget http://repo.mosquitto.org/debian/mosquitto-repo.gpg.key
sudo apt-key add mosquitto-repo.gpg.key

If you are running Sketch

wget http://repo.mosquitto.org/debian/mosquitto-stretch.list

If you are running Buster

wget http://repo.mosquitto.org/debian/mosquitto-buster.list

then

apt-get update

If you have any issues. Take a look at The Level 1 Way guide listed below. You may need to install some additional packages.

Setup Monitor
pi@raspberrypi:~ $ git clone https://github.com/andrewjfreyer/monitor.git
pi@raspberrypi:~ $ cd monitor/
pi@raspberrypi:~/monitor $ chmod +x ./monitor.sh
pi@raspberrypi:~/monitor $ ./monitor.sh

I suggest running the command a few times to learn how monitor.sh works. Also this needs to be done to create the initial setup files that we will be editing. You might need to run the command with sudo if you are not logged in as root. When you are satisfied check that monitor is running with:

systemctl status monitor

If not:

systemctl enable monitor
systemctl start monitor

I will not document how I edited the /etc/systemd/system/monitor.services file. You will find information on options that others have used in the links below.

Next add any BT MAC addresses that you know to the known_static_addresses file.

One thing to note. The alias will be the name of the device in MQTT. If there is no alias, the MAC address will be used. More on this later.

Warning

If you are monitoring a Tile Device do not place it in the known_static_addresses. This will make monitor see the device twice. Once with confidence 100% and again with 0%. The work a round that I have seen it to not place its MAC address in the file. You will need to use the MAC address instead of an alias in the sensor configuration.

References

# ---------------------------
#
# STATIC MAC ADDRESS LIST
#
# 00:00:00:00:00:00 Alias #comment
# ---------------------------
 00:00:00:00:00:00 person1_Phone

Configure mqtt_preferences so that we can connect and publish to our MQTT topics. 

# ---------------------------
#
# MOSQUITTO PREFERENCES
#
# ---------------------------

# IP ADDRESS OR HOSTNAME OF MQTT BROKER
mqtt_address=192.168.X.X

# MQTT BROKER USERNAME
mqtt_user=mqtt_username # This is what was configured on the MQTT Server.

# MQTT BROKER PASSWORD
mqtt_password=password #Same case as username.

# MQTT PUBLISH TOPIC ROOT
mqtt_topicpath=monitor # <- most configs use this.

# PUBLISHER IDENTITY
mqtt_publisher_identity='livingarea' #<- ID for one of the Pi servers eg. Pi Zero W

# MQTT PORT
mqtt_port='1883'

# MQTT CERTIFICATE FILE
mqtt_certificate_path=''

#MQTT VERSION (EXAMPLE: 'mqttv311')
mqtt_version=''

Note

mqtt_topicpath should be the same on each of your monitoring servers.

mqtt_publisher_identity must be unique for each server that will be sending MQTT messages to the HA server.

Test that MQTT server is getting the new notifications from your Pi devices.

mosquitto_sub -h 192.168.X.X -u username -P passwd -t monitor/#

# Output
{"id":"00:00:00:00:00:00","confidence":"100","name":"person1_Phone",
  "manufacturer":"Apple Inc","type":"KNOWN_MAC","retained":"true",
  "timestamp":"Fri Nov 06 2020 ...."
}

Here we can see that devices are being seen and their confidence level from the monitor.sh is being reported.

At this point, after setting up all of the monitoring devices, it is time to move onto setting up HA.

Home Assistant Configuration

Setup the sensor part of the configuration

We need to collect the MQTT messages into HA

- platform: mqtt
  state_topic: 'monitor/front/person1_phone'
  value_template: '{{ value_json.confidence }}'
  unit_of_measurement: '%'
  name: 'Person1 Phone Front'

- platform: mqtt
  state_topic: 'monitor/livingarea/person1_phone'
  value_template: '{{ value_json.confidence }}'
  unit_of_measurement: '%'
  name: 'Person1 Phone Living Area'

Tile Device Example

- platform: mqtt
  state_topic: 'monitor/front/XX::XX:XX:XX:XX:XX'
  value_template: '{{ value_json.confidence }}'
  unit_of_measurement: '%'
  name: 'Person1 Phone Front'

- platform: mqtt
  state_topic: 'monitor/livingarea/XX::XX:XX:XX:XX:XX'
  value_template: '{{ value_json.confidence }}'
  unit_of_measurement: '%'
  name: 'Person1 Phone Living Area'

Note

  1. I have two entries as I have two devices running monitor in two locations in my home.
  2. The topic is person1_phone which matches the alias used in the known_static_addresses file. If there was not an alias. These would be the actual MAC Addresses.

The next part is still a work in progress. This is still in the sensor.yaml file.

- platform: min_max
   name: "Person1 Phone Home Confidence"
   type: mean
   round_digits: 0
   entity_ids:
     - sensor.person1_phone_front
     - sensor.person1_phone_living_area

This combines these two sensors and return the mean of their two values. In my case this often returns 50% since only one monitor server can detect the phone based on where it is.

Next we create a sensor that will return a 'True' or 'False' state. As mentioned my min_max generally returns 50%. So I want to have 'True' if the value is > 45% for safety.

- platform: template
  sensors:
    is_person1_home:
      friendly_name: 'Is Person1 Home?'
      value_template: '{{ state_attr("sensor.person1_home_confidence","mean") | float > 45 }}'

The value_template could probably be changed to states('sensor.person1_home_confidence').

At this point we have a sensor that returns true or false if it can see the bluetooth device we are looking for. But it's not actually connected to any HA automations.

In my existing configuration I am using

- platform: bluetooth_le_tracker

- platform: bluetooth_tracker

Which auto populates the known_devices file. These devices are then used as triggers for my automations. I want to avoid making larges changes. So we are going to make some virtual device_trackers. These will replace the ones created using the provided bluetooth trackers.

In the devices_tracker configuration file we will add something like:

- platform: mqtt
  source_type: 'bluetooth'
  devices:
    person1: 'location/person1'

We are basically saying that we are want an MQTT Topic called location/person1. We will be publishing state to this with some scripts later.

This is where I actually got stuck and it wasn't until I found this bit of wisdom that things fell into place.

We need to manually add entries to the known_devices file.

person1:
  hide_if_away: false
  icon:
  mac:
  picture:
  vendor:
  track: true
  name: Test Person

We now have a device_tracker.person1 which will have its state taken from MQTT:location/person1

Note

If you test this state you will get a source: null. This will not be set until we first publish to MQTT.

Moving on to the scripts

Now we need to start being able to update the MQTT:location/person1 so that device_tracker.person1 will have either a 'home' or 'not_home' state.

We will edit our script configuration files.

'person1_home':
  alias: "Person1 Home"
  sequence:
    - service: mqtt.publish
      data:
        topic: location/person1
        payload: 'home'

'person1_away':
  alias: "Person1 away"
  sequence:
    - service: mqtt.publish
      data:
        topic: location/person1
        payload: 'not_home'

These two scripts will update the device_tracker so that we can use their state. We will need an automation so that the state is updated.

But I will add a bonus script here as well. This will trigger a bluetooth rescan. This can be triggered on a restart of HA with an automation.

'bt_rescan':
  alias: "Issue BT Rescan"
  sequence:
    - service: mqtt.publish
      data:
        topic: monitor/scan/restart
        payload: ''

Add the following configuration to automations.

- alias: Set Person home
  initial_state: 'on'
  trigger:
    - platform: state
      entity_id: sensor.is_person1_home
    - platform: homeassistant
      event: start
  condition:
    - condition: state
      entity_id: 'sensor.is_person1_home'
      state: 'True'
  action:
    - service: script.person1_home

- alias: Set Person1 away
  initial_state: 'on'
  trigger:
    - platform: state
      entity_id: sensor.is_person1_home
    - platform: homeassistant
      event: start
  condition:
    - condition: state
      entity_id: 'sensor.is_person1_home'
      state: 'False'
  action:
    - service: script.person1_away

This is where we link everything together. We also have the automations trigger when HA starts up. So we get some initial state.

I personally also opted to have a BT scan triggered when ever HA restarts.

I added this configuration to automations.

alias: "HA Started"
initial_state: 'on'
trigger:
  platform: homeassistant
  event: start
action:
  - service: script.bt_rescan

The final step is the replace all the previous device_tracker references with the new manaully created ones listed in known_devices.yaml

Final Thoughts

This is not yet an Ideal setup. I am still working on it. But if you look at the blog links below you might get some more ideas. I am still reading through them and improving things.

As I stated at the start. This is mostly for me so that I have some documentation for myself.

But I hope others might find it useful. Since I had to work through it and piece it together.

Thanks to those who posted the work online. It was invaluable. The main part I found missing was the known_devices.yaml

References

The config is far beyond what I need. But it's a great resource.

Some missing Magic

Software