I’ve created an openHAB Page with various weather information (e. g. temperature, humidity, etc.). To not always open a browser tab on my smartphone or tablet, I’d love to have a dedicated device to display the openHAB dashboard and see when just walking by. It should meet the following requirements:
Consume as little energy as possible
Battery-powered
No user interaction necessary to display/update the openHAB Page (automatic reload, screen always on)
For #1 and #2, an E-Ink device seems like a proper choice to me, so I tested it with my PocketBook Touch HD 3 - and it worked (#3 as well)
Since I need my E-Reader for reading, I need another device, so I gave our old Kindle a try as well - without luck, openHAB is not even rendered.
Since I don’t want to buy another PocketBook just for displaying openHAB due to its price, I’m curious what kind of device you guys out there are using. In other words, I’m looking for the cheapest possible option to render an openHAB page and fulfilling my needs.
I haven’t checked in on this project in a while, but it looks like it’s waaay further along than it used to be – https://inkbox.ddns.net/ I bought a Kobo Glo HD (they’re pretty cheap used) for this purpose some time ago – but it’s just been collecting dust. The project is centered around being an actual e-reader of course, but has modern web browser support which should pretty much be all that’s needed. The list of supported devices includes a bunch of Kobo’s that are pretty cheap on ebay.
There are some HA users that are using a slightly different approach with and e-ink screen powered by ESPHome enclosed in picture frames. See here for a couple of examples:
What I still don’t understand with these kind of solution: how would rendering the openHAB dashboard work? I mean, it’s only a small ESP32 without a browser
Wouldn’t I need a certain kind of middleware to built a dashboard with the measured values from openHAB’s REST API to built an image that the ESP32 could render?
Usually an ePaper outside of an eReader comes “ePaper-only” and you’ll have to tell it, where to put text, where to put images yourself. AFAIK there’s not “HTML2ePaper”-functionality outside of built-in browsers like in eReaders.
e.g. there’s a wrapped respository in ESPHome, which allows for Waveshare ePapers to display information. You have to calculate the positions on X-Y axis to place text/images yourself.
…or you’ll have to use an ePaper-like hardware, which comes with a browser capable of displaying openHAB GUIs.
if you want to 100% display openHAB GUI then you’ll need a cheap eReader and let it run an openHAB page in kiosk mode. Plus side: you’ve already got a battery powered device. Down side: could be a bit more expensive.
If you’re willing to dig a bit deeper, you can try to use an ESP8266/EPS32 and a simple ePaper display attached to it. You then can send openHAB items via MQTT binding and the ESP then will display them.
Plus side: should use even less battery. Down side: you’ll need to built that yourself.
I’ve also seen people also using them for things like a battery powered display outside the home office showing busy status (linked to MS Teams availability).
Apologies for the slight diversion but i thought it might be interesting for people to be aware of these use cases. A family calendar to check the day before leaving the house send another great use case where it doesn’t need updating very often.
No user interaction necessary to display/update the openHAB Page (automatic reload, screen always on)
Can render an openHAB page
Cheapest possible option and less expensive than a Pocketbook Touch HD 3
1-5 are covered by a Pocketbook Touch HD 3. You might find an e-reader that’s $20-50 cheaper, but you can’t be sure it will render an openHAB UI until you try it–whereas you already know the Pocketbook works.
In contrast, 3-6 are covered by an Android phone/tablet. So, how flexible are you on “Has an e-ink display” and “consume as little energy as possible”?
I have an old Amazon Fire HD 10 running the HabPanelViewer app to display an openHAB UI (which doesn’t have to be a HabPanel). It’s in airplane mode (so that WiFi is the only radio in use), and I use rules to determine when the screen is on/off. When no one is at home or awake, the screen is off.
I also experimented with having the screen turn on only when someone walks in front of it, but I didn’t find a reliable solution and didn’t come back to it.
Don’t get me wrong–I really like e-ink displays. I’m just not confident that you’ll find a device that meets all of your requirements, in which case you’ll need to broaden your parameters. For an off-the-shelf solution, I think your best options are:
Use your existing Pocketbook Touch HD 3 for openHAB and get a new (and better?) e-reader.
Might as well use this as an excuse to upgrade.
Find a lightly used Android device to repurpose. If you don’t already have one, someone you know probably does.
I’d be hesitant to buy a used Android device (you can’t trust the battery health), but I’d take one for free.
I built a family calendar based on Google calendar a 8266 and a cheap little e-paper. Although this was quite easy from the concepts of getting the data, parsing it, … the e-paper in combination with the 8266 drove me nuts. Memory on the 8266 is very limited and the display needs a pre-generated image in the memory and if you have a display with more then one color you need such images for every color.
There are different toolsets to use more than the built in typefaces, … but as I constantly got into trouble with memory I reduced my expectations and just used the standard typeface without special german mutated vowels and a very basic method to count/wrap lines and insert headlines. I would have loved to use logos/images, but this would have been very time consuming and would have probably led to more problems with memory.
If you want to give it a try, I would suggest to start with low expectations on a basis of getting data from openHAB via MQTT e.g. and just a textual display in key value tuples line by line and forget about rendering something like a openHAB panel.
As I wrote earlier: There’s a neat little library for ESPHome, which does all the heavy lifting for you and you’ll only have to configure some YAML for that. Works ATM for black&white ePapers unfortunately, but I’ve got no problems using that with a bunch of icons and german umlauts for my waveshare, a little documentation for it:
sounds interesting. I have a like 12year old Kobo still somewhere in my drawer…
Please share your experience here - especially if the browser supports refreshes!
Okay my dear openHAB friends - unfortunately no good news…
As I mentioned one month ago, I bought a refurbished Kobo Nia and wanted to give InkBox a try. I did so, but I had the Midas touch: my Kobo Nia has a different hardware and therefore the already existing port of InkBox doesn’t work
So I chatted with the InkBox guys for quite some time and we’re now at the point that I would have to port it on my own (compile the necessary stuff, etc.). Unfortunately, I don’t have enough time (and to be honest: enough interest) for this low-level work.
@binderth since the E-Reader approach seems to be a dead end, I consider using ESPHome on a Raspberry Pi Pico with a Waveshare E-Ink display. I broke it down into the following steps:
Render dashboard to image file.
Transfer image file to Raspberry Pi Pico.
Render image file with ESPHome.
For #1, I’m evaluating whether I use my existing openHAB dashboard or build a new one with my favorite web technology (ASP.NET Core Blazor) and somehow render it to an image file.
#3 seems pretty straight forward as soon as I have an image file.
What remains unclear to me is #2 - with ESPHome, what is the preferred way of transferring an image file from a remote source (in my case another Raspberry Pi 4) to a Raspberry Pi Pico? Via SSH and a CRON job?
I am using an weaver share e ink display with esp32s…on my openhabian I make screenshots from the 3d view of my flat and esp32s download the image display the flat on my e ink. I’m addition I use an 4 wires resistive touch to do some basic stuff
My approach would be to put all the “static” content to the Pico up front: icons, background images, whatever you need. the Pico can then only listen to “dynamic” information like item states and stuff via MQTT.
you could even plug the E-Ink display directly to a ESP8266 or ESP32 and let it deep sleep and run it completely off batteries?
(#3 as well)
