Automatically turn on tv when streaming to a Chromecast

I’m all in favor of “dumb” TVs combined with a Chromecast or Apple TV. I used to have a smart button that could toggle a smart switch to turn on my TV, which helped reduce standby mode when we weren’t using it. However, pressing the switch was an extra step that I often found inconvenient. That’s why I recently implemented a simple automation that turns on the TV automatically. Now, I can’t imagine why I didn’t set this up sooner - it’s so easy and convenient. In general, it’s a good lesson that sometimes the most simple automation can have the most practical impact.

(Hardware) requirements

• HomeAssistant with NodeRED
• A media player connected to the TV and configured in HA. I use a Chromecast.
• A smart switch that controls power to the TV (e.g., a Innr smart plug).

Flow

The flow is effortless. When you connect to a Chromecast from a device (e.g., a smartphone), the state of the media player in HA goes from off to idle. I use that state change to turn on the TV. Usually, when the Chromecast has started the streaming service, the TV also completes its startup routine.

To turn off the TV, I do the reverse. If the state goes to off for 5 seconds, I turn off the smart switch. The five-second delay is used to disable the automation when switching from streaming services. E.g., if you switch from Netflix to Youtube on your Chromecast, it briefly goes to off. Including a 5-second delay fixes that.

Source code

You can import the flow directly in NodeRED using the following snippet:

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