Triggering a wall tablet page once after the garage door closes

Apps SmartHome Integration
1

Hi,

I am experimenting with a small arrival automation using Garadget, Home Assistant and a wall-mounted Android tablet.

The intended sequence is:

  1. The garage door opens.
  2. The car enters.
  3. The garage door closes.
  4. Garadget reports that the door has remained closed for about 15 seconds.
  5. Home Assistant wakes the wall tablet.
  6. The tablet opens a specific browser page.
  7. The automation does not run again until the garage has completed another genuine open and close cycle.

This is the interactive page I am currently using as the tablet destination:

https://deckaura.com/pages/free-tarot-reading

Disclosure: I maintain the linked website. I am sharing it only to show the actual browser page used in the automation.

Garadget is currently available in Home Assistant as a cover entity, but I am also considering using its local MQTT status messages directly.

My main questions are:

1. Best event source

Would you trigger this from the Home Assistant cover state or subscribe directly to the Garadget MQTT status topic?

My priority is reliable detection rather than the fastest possible response.

2. Detecting a completed arrival cycle

I do not want every transition to closed to launch the tablet page.

The automation should require a sequence similar to:

closed
open or opening
open
closing
closed for 15 seconds

Would you implement this as a Home Assistant automation, a helper-based state machine, or a Node-RED flow?

3. Avoiding false triggers

Garadget can publish repeated status updates even when the physical state has not meaningfully changed.

What is the cleanest way to prevent duplicate launches?

I am considering storing:

arrival_cycle_active = true
tablet_page_opened = false

The first genuine open event would activate the cycle. The first stable closed event would launch the page and mark the cycle as completed.

4. Door opened without a vehicle arrival

The door may also be opened for ventilation, maintenance or taking something out of the garage.

Would you combine the Garadget state with another condition such as:

  • Phone entering the home zone
  • Connection to the home WiFi
  • Car Bluetooth disconnecting
  • Motion detected inside the garage
  • A vehicle-presence sensor

I would prefer to avoid opening the tablet page when someone simply operates the door from inside the house.

5. Local MQTT versus cloud integration

For this type of non-critical automation, is there any practical advantage to using local MQTT rather than the normal Garadget cloud integration?

The garage door itself would still be controlled normally. MQTT would only be used as the event source for the arrival scene.

6. Tablet command

For waking the Android tablet and opening the URL, I am considering Fully Kiosk Browser or a Tasker webhook.

Has anyone used either of these with a Garadget-triggered Home Assistant automation?

I need the command to:

  • Wake the display
  • Bring the browser to the foreground
  • Open or refresh the URL
  • Avoid creating multiple browser tabs
  • Return to the normal dashboard after a few minutes

7. Restart recovery

If Home Assistant restarts while the door is open, I do not want the eventual closed state to be incorrectly treated as a completed arrival.

Would you reset the state machine after every restart, or reconstruct the cycle using Garadget’s last-change information?

I am starting with a one-door setup and would appreciate any recommendations on reliable debouncing and arrival-cycle detection.