ads' corner

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.

My plan is to reinstall openHABian on a bigger SDcard, and on a Raspberry Pi 4. The latest release (v1.5) supports the new Pi 4, and I decided it's time to do a fresh install, and see if all my Playbooks are still working.

Raspberry Pi 4 with Sectronics Armor (cooling) Case

As always, I'm searching my shell history for the right command how to install the image ... but came up empty.

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.

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.

The "Deutscher Wetterdienst" DWD (German Weather Service) provices a service which sends out alarms for upcoming events, like heavy rain, storm, blizzard, strong winds ect. This service is only available for Germany. And it has a binding for openHAB. Time to integrate this, activate a number of regions I'm interested in, and send notifications to our mobile phones.

At this point I'm really happy that I deploy my openHAB with Ansible, I can use the Template module and loop over the Items, Things and Rules.

The Binding can "track" multiple regions, so called Cell IDs. I'm interested in 4 different Cells (the list is available here), your mileage might vary. For each reagion there can be multiple messages - and although every single example I found only assumes there is only one message (warningCount=1), I already had a situation where a Cell had two warnings. That information likely goes missing if you set warningCount to 1. Given how much configuration overhead it is when you add more channels, I can understand why most examples stay at "1" for warningCount. Doubling the number doubles the number of Items (12 -> 24). However since I deploy everything in a template, that's not a problem here.

I started this with a generous warningCount=5 - and in my templates I just loop from 1 to 5, and over every Cell, and generate all the necessary Things and Rules for every channel.

Ok, the details: