ha-catt-fix

This is a solution for the timeout issue when casting Home Assistant using CATT.

Installation

1. It is recommended to install this with HACS by adding a custom repository (important: select "Lovelace" as category). Alternatively, download ha-catt-fix.js and put it inside /config/www/.

2. Add it as a resource to your Home Assistant UI. Follow the instructions displayed by HACS. If you are not installing with HACS, then:

   If you use the YAML mode, put the following in your configuration.yaml:

   lovelace:
     mode: yaml
     resources:
       - url: /local/ha-catt-fix.js
         type: module
   

   Otherwise go to Settings -> Dashboards -> (three dots in the upper right corner) -> Resources.

3. In case of the YAML mode, a restart of Home Assistant is required.

That's it. Continue to use CATT for casting HA to your display but dismantle anything you had set up to re-cast it every 10 minutes.

How does it work

The reason for the timeout is that nothing is being played so the receiver application gets closed. The solution for that is to add a hidden Cast media player component and play an image every 9 minutes. That is not new, it has been used in the official Home Assistant Cast integration for quite a long time.

However, there's one problem with DashCast (which is used by CATT to cast websites). It replaces itself with the target website (window.location = url). It means it looses control of the display. That's why this solution is to embed the receiver code into the Home Assistant UI itself and do the dummy playback there.