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There are a number of ChromeCasts in our setup. I'm adding (physical) switches to turn displays on and off, and primarily control the volume. When I turn the display off, I also want the ChromeCast to stop doing whatever it is doing right now (stop streaming), and go back to the default application (for video CC).

The openHAB ChromeCast binding has a separate channel for that:

Switch    chromecast_chromecast_dfb5af5187ce1135b276239130aef282_stop     { channel="chromecast:chromecast:dfb5af5187ce1135b276239130aef282:stop" }

However since the channel is named "stop", it has to be "enabled" with "ON". Doesn't make sense? It is as it is:

chromecast_chromecast_dfb5af5187ce1135b276239130aef282_stop.sendCommand(ON)

And the result:

2021-01-18 17:13:20.305 [ome.event.ItemCommandEvent] - Item 'chromecast_chromecast_dfb5af5187ce1135b276239130aef282_stop' received command ON
2021-01-18 17:13:20.321 [nt.ItemStatePredictedEvent] - chromecast_chromecast_dfb5af5187ce1135b276239130aef282_stop predicted to become ON
2021-01-18 17:13:20.443 [vent.ItemStateChangedEvent] - chromecast_chromecast_dfb5af5187ce1135b276239130aef282_appName changed from <...> to UNDEF
2021-01-18 17:13:20.451 [vent.ItemStateChangedEvent] - chromecast_chromecast_dfb5af5187ce1135b276239130aef282_appId changed from <...> to UNDEF
2021-01-18 17:13:20.455 [vent.ItemStateChangedEvent] - chromecast_chromecast_dfb5af5187ce1135b276239130aef282_statustext changed from Casting: <...> to UNDEF
2021-01-18 17:13:20.457 [vent.ItemStateChangedEvent] - chromecast_chromecast_dfb5af5187ce1135b276239130aef282_idling changed from OFF to ON
2021-01-18 17:13:23.888 [vent.ItemStateChangedEvent] - chromecast_chromecast_dfb5af5187ce1135b276239130aef282_appName changed from UNDEF to Backdrop
2021-01-18 17:13:23.893 [vent.ItemStateChangedEvent] - chromecast_chromecast_dfb5af5187ce1135b276239130aef282_appId changed from UNDEF to E8C28D3C

In my ongoing endeavor to improve our home, a while ago I added a notification when the washing machine and the dryer are finished. The notification is send to a Telegram channel. Over the summer vacation I added a number new ChromeCast Audio devices (Google no longer offers the Audio CC, if you need one get one now). One is placed in the kitchen. Not only can I listen to music while eating breakfast, I can also output notifications, by using the CC as an audio sink in openHAB.

To make that useful, I decided to use a Text-to-Speech system. openHAB offers a couple different TTS systems, however most of them need a cloud integration, and therefore a working Internet connection. The "Pico TTS" works standalone, and was my favorite choice for this implementation.

After figuring out if a ChromeCast is currently used, it was time to fix a long-standing problem. At home we don't have TVs, just "dumb" displays, and stream content using ChromeCasts. However a video ChromeCast never really turns off, but keeps the display running, using a "Backdrop" app. This app keeps showing pictures on the display when the ChromeCast is not used otherwise, effectively preventing any powersafe mode.

That's both annoying (who wants to have pictures shown in the living room or working room all night), and consumes energy. It's also intentional by Google. So far we had to turn the display on and off manually, which is inconvenient.

We have a couple of Audio and Video ChromeCasts in use. For an upcoming project I need to figure out if any of them is currently used. That is different for the Audio and the Video devices: the Audio just goes idle=ON, the Video devices however load the "Backdrop" app and show pictures when idling. Google for whatever reason does not want the attached monitor to go in powersafe mode. So much for saving energy ...

All of the action needs between a few milliseconds and 2-3 seconds once you start/stop using the ChromeCast.

A previous blog post explains how I add the ChromeCast devices. And I have monitoring in place.

I really like to monitor things, to catch issues early on. In our home we have a couple ChromeCasts, both Audio and Video. They are all connected to the openHAB system, Once in a while they stop working, and need to be restarted (unplugged and plugged in again). Unfortunately you usually only find that out when you want to stream something, and wonder why either the ChromeCast does not show up in the device list, or does show up but does not accept the media.

Therefore I decided to monitor the devices in openHAB.

After starting to look into openHAB, and automate the installation with Ansible, I discovered that there is an API, but the main focus of the documentation and examples clearly is on using the UI and don't automate the installation. It takes some time to figure out the details. In my last blog post I automated the installation of extensions/bindings, and ended with running a rediscover scan.

Now it's time to see if there are new items in the inbox, and possibly auto-approve and link them in Ansible.

Recently I started looking into Home Automation, using a Raspberry Pi and the openHAB as platform. The website provides ready-to-go images based on Debian, named openHABian. Me being me, I decided to install the image, let it boot up for the first time, and then take it from there using Ansible as automation tool. That's a bit more effort in the beginning, but ensures that I can always just wipe the SDcard, and start over from the beginning. Especially useful if I screw up at some point during testing.

One of the first steps to do is to decide which bindings, or extensions, are needed. Bindings provide openHAB with information about what kind of hardware and input sources are available out there. The list of available bindings is long, and one can use the UI to click and install bindings, before starting to configure and link them. That process is not idempotent, but luckily openHAB also provides an API which can be used to execute the same steps, just faster and automated.