Create an LED message display board that is connected to an MQTT broker to show variable message text and a border. In my personal use case, since I work from home full-time, I wanted a way to alert my family members that I was unavailable due to being in a virtual meeting/phone call.

In my setup, the MQTT broker is the Mosquitto broker add-on for an existing Home Assistant instance, but theoretically any MQTT broker and host could be made to work. I have only tested this with HomeAssistant, however.

Click the image below to see a demonstration video!

This code is written for the Adafruit MatrixPortal M4 board, running CircuitPython 6.3.0. For information on this board and to download the correct CircuitPython version, visit https://circuitpython.org/board/matrixportal_m4/

Then, follow the instructions on how to install CircuitPython on the board: https://learn.adafruit.com/welcome-to-circuitpython/installing-circuitpython#installing-circuitpython

Download the CircuitPython libraries that are compatible with 6.3.0 from https://circuitpython.org/libraries

The list of libraries in that bundle needed to run the code in this repo is:

• adafruit_bus_device
• adafruit_display_shapes
• adafruit_display_text
• adafruit_esp32spi
• adafruit_io
• adafruit_matrixportal
• adafruit_minimqtt
• adafruit_portalbase
• adafruit_fakerequests.mpy
• adafruit_requests.mpy
• neopixel.mpy

First, install and configure the Mosquitto Broker add-on for HomeAssistant if you've not already done so. See https://www.home-assistant.io/integrations/mqtt/

Next, we will configure a script in Home Assistant that is intended to send a message to our MQTT service to a topic that begins with "home-assistant/message-board/" and allows for variables to be passed for the "board_number" and "topic_name", and a payload that contains a "message" and "mode" variable. These variables will be passed to the script from another entity.

publish_notification_to_message_board:
  alias: Publish a message and action notification to a message board
  sequence:
  - service: mqtt.publish
    data:
      topic: >
        home-assistant/message-board/{{board_number}}/{{topic_name}}
      payload: >
        { "message": "{{message}}", "action": "{{mode}}" }
  mode: single

Save this script to whatever file that houses other scripts in your Home Assistant instance. By default, I believe it is simply /config/scripts.yaml

Then, we will configure two entities in Home Assistant:

• An "input boolean" that will be used to track the 'state' of our message board; and
• A "template switch" that will toggle the state of the input boolean, and trigger the appropriate script for each 'state'

Create a new file called "/config/input_boolean.yaml" (if it does not already exist) and create a new entry in that file that looks something like:

in_a_meeting:
  name: On a Call
  initial: off

The main outdented value is the system name of this input_boolean, and the 'name' property will be used for display purposes.

Then, create a new file called "/config/switch.yaml" (if it does not already exist) and create a new entry in that file that ties the scripts and input_boolean together:

- platform: template
  switches:
    in_a_meeting:
      friendly_name: On a Call
      value_template: "{{ is_state('input_boolean.in_a_meeting', 'on') }}"
      turn_on:
        - service: input_boolean.turn_on
          entity_id: input_boolean.in_a_meeting
        - service: script.publish_notification_to_message_board
          data:
            board_number: 1
            topic_name: meeting
            message: On a Call
            mode: "on"
      turn_off:
        - service: input_boolean.turn_off
          entity_id: input_boolean.in_a_meeting
        - service: script.publish_notification_to_message_board
          data:
            board_number: 1
            topic_name: meeting
            message: Not on a Call
            mode: "off"

Basically, what this switch does is toggle the 'state' of our 'in_a_meeting' input_boolean, and trigger the script for that 'state'. The 'message' of the payload is what gets displayed on the LED Matrix, and the 'action' determines whether or not the Matrix is lit - "on" makes it show the border and text, "off" hides them. You could send the action "on" for both states, which would mean that one message would be shown or the other would be shown. I have mine simply turning off when I am "Not On a Call". This switch will now be available on the Home Assistant UI dashboards as an entity card.

The code running on the MatrixPortal was written to be configurable in two ways. There is a 'secrets.py' file which is intended to house sensitive information like your WiFi credentials as well as the MQTT credentials. This repo has a 'secrets-example.py' file that outlines the expected format. The CircuitPython libraries for connecting to WiFi expect an object called 'secrets' with the properties 'ssid' and 'password'. This repo has also added an object called 'mqtt' that is used to configure the connection to your MQTT broker. The full file should look like this, with the appropriate values filled in:

secrets = {
    'ssid' : '', # WiFi network name
    'password' : '' # WiFi network password 
}

mqtt = {
    'broker': '', # MQTT broker url or ip address
    'user': '', # MQTT user name
    'password': '' # MQTT user password
}

Additionally, there is a 'config.py' file that is intended for less sensitive information. This is where you will create a new object called 'feeds' containing any MQTT topics you want the MatrixPortal to subscribe to. An example of this is also included in the repo - change the name to something meaningful, if desired, and value to match the topic you are publishing to from Home Assistant:

feeds = {
    'meetings': 'home-assistant/message-board/1/meeting'
}

The previous usage of the script (https://github.com/EBOOZ/TeamsStatus) that reads the log files for status changes no longer works with the latest version of "New Microsoft Teams". I'm currently using the awesome (https://github.com/geoffreylagaisse/Hass-Microsoft-Graph) Micorsoft Graph API HACS integration. This requires access to the MS Graph API which may be hard to achieve depending on your organization's security policies.

Using this awesome script that can detect status and activity changes in Microsoft Teams and send those changes to Home Assistant (https://github.com/EBOOZ/TeamsStatus), I've successfully automated flipping the "On a Call" switch based on my MS Teams activity. Follow the instructions on that page to get the script working and the base HA configurations necessary to acknowledge the status and activity, then add the following automations (I used the UI to create them, but you can copy and paste these directly into the automations.yaml file, or replicate them in the UI):

- id: '{{something_unique}}'
  alias: MS Teams - In a call
  description: ''
  trigger:
  - platform: state
    entity_id: sensor.teams_activity
    to: In a call
  condition: []
  action:
  - service: switch.turn_on
    target:
      entity_id: switch.in_a_meeting
  mode: single
- id: '{{something_unique}}'
  alias: MS Teams - Not in a call
  description: ''
  trigger:
  - platform: state
    entity_id: sensor.teams_activity
    to: Not in a call
  condition: []
  action:
  - service: switch.turn_off
    target:
      entity_id: switch.in_a_meeting
  mode: single