openHAB can integrate Google Calendars. The functionality is kind of limited, it can only see the current and the next calendar event, but in my case that is enough. More about the use case in another blog post.
There are three different calendar bindings available, let's have a quick look:
- CalDAV Personal Binding: this is a v1 binding, which means it will no longer work in the soon-to-be-released openHAB v3. Apparently this works with Google calendars, but has performance issues. It can show the current and next event.
- Google Calendar Scheduler: also a v1 binding. Needs more work for presense simulation, and additional bindings.
- iCalendar Binding: v2 binding, should work with v3. It can show the current and next event. That's the one I'm going to use.
Continue reading "Add a Google Calendar to openHAB"
openHAB rules files are lazy loaded. When a rule is used the first time, the entire rule file is loaded and compiled, which apparently is single-threaded and takes a couple seconds. Even on a reasonable powerful Rasperry Pi 4. This happens both after restarting openHAB and after changing the rules file. It also means that whatever the rule in question is supposed to do has to wait a couple seconds when requested for the first time. Imagine you have a light switch, enter a room, press the switch, and it takes 5-10 seconds until the light comes on.
To work around this problem, I add a piece of code in all rules files which triggers an immediate action right after loading the file. This way the rules file is already pre-loaded (which again takes a couple seconds, but likely at a time when the rule is not needed right now).
Continue reading "openHAB: faster loading of rules files"
A while ago someone mentioned "reminders" used in their home audio system, and I took that idea and implemented something similar in openHAB.
The basic idea is that I can send scheduled notifications to any audio sink openHAB is using, possibly more than one audio sink for one message. Also I want to differentiate between a simple audio sound, and text output.
For the text audio output I installed Text-to-Speech a while ago, this enables the ability to output text as audio in different languages. In addition I want an information when a reminder is "fired" in my Telegram control channel. As audio sink I'm mostly using ChromeCasts here, but anything openHAB can connect to is usable here.
Continue reading "Audio reminders in openHAB"
A while ago I integrated DWD warnings (Deutscher Wetterdienst) into our home automation system, and receive severe weather notifications ever since then. That works quite good, but it was missing a weblink with more details - or if you want to forward the warning to someone it would be useful to have a link to the warning as well. The DWD binding does not provide that piece of information, but it is easy enough to add - or so I thought.
Continue reading "openHAB, Telegram Bot and quoting URLs"
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.
Continue reading "Text-to-Speech in openHAB"
In my previous blog post about "Tankerkönig" I explained the details of how to integrate this binding into openHAB and provide a Telegram interface.
Someone on the openHAB community forum pointed out that Telegram bots allow queries, where one can present the user with options, and the user only has to click on one of the options. That makes it easier to use, and less typing is required as well. I went ahead and implemented that.
Continue reading "openHAB and Tankerkönig gas prices + Telegram integration - Second iteration"
A simple task, or so I thought: in a Jinja template keep track of the number of items in a loop. And then use that count afterwards.
Disclaimer: the number of items is not equal the number of times the loop runs, so I can't use the loop variables.
Turns out that Jinja has other opinions, and variables inside a loop are all local. When a variable is changed inside the loop, the scoop of the variable stays local, and once the loop ends the original value of the variable is restored. That's even true for variables which are created outside the loop.
Continue reading "Use namespace as global variable in Ansible Jinja templates"
By default, openHAB only starts 5 threads to deal with execution of Rules. That's not a lot, and if all threads are busy, rules have to wait until a slot is free. This results in slow Rule response time.
This can be improved.
Continue reading "Improve openHAB Rules response time"
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.
Continue reading "openHAB: Turn display on and off for a Video ChromeCast"
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.
Continue reading "openHAB: detect if a ChromeCast is currently used or idle"