Hi Guys,
I’m new in OH world. This is my case:
I have old PC monitor and want to utilize it for displaying some information on Paper UI. Do I have to buy Android HDMI dongle to run the Chrome on my Monitor or is there a way to run Chromium or other Linux browser on openhabian, connect R Pi with monitor using HDMI cabel and simply display Paper IU on Chromium or other Linux browser?
Thanks
No openHABian does not include a Linux desktop because it is not powerful enough to run OH in parallel to a windowing environment.
You can access PaperUI from any device that has a browser such as your PC or smartphone.
I need no desktop but web browser only. I’m asking hypothetically. Assuming I have Chromiun web browser installed on openHABian, would it be possibile to set everything up in the way described in my first post?
In theory, yes. In practice, no. To set up chromium you need a windowing environment to run. The pi is not powerful enough to do all of that.
You will need the desktop environment for the browser to work. That’s not included with openhabian so you would have to add and configure all the packages yourself, and your Pi will likely bog down because it just doesn’t have the amount of memory you need for this task. Drop that idea, please. Use a PC, smartphone, tablet or whatever device as your client, that’s what HTTP was invented for.
If despite the warnings you want to give this a try (sometimes you just gotta burn your finger to believe the stove is hot), assuming you are running at least an RPi 3, install Raspbian Desktop. Then follow the instructions for openHABian manual installation.
But as has been said, there really isn’t enough RAM to run the full windowing environment, chromium, and openHAB at the same time on an RPi. And you cannot run a graphical program (i.e. Chromium) without the windowing environment.
Thanks guys, Looks I have to drop this idea. Too many votes for “NO” from people with great experience.
So I will have to use Android dongle connected to the monitor. This is charity venture and I’m trying to build something from nothing becase the budget is limited. Can you suggest some cheap dongle for that? It does not have to be powerfull. The only think to do is displaying Paper UI in web browser.
Given that PaperUI is for admin purposes only and you rarely need to touch it again once you’ve setup all things to run, what about a temporary solution such as to bring your laptop in these rare cases.
Or use someone’s personal phone (I assume you have WiFi in there, and even if you don’t, you can temporarily setup any smartphone to do tethering i.e. to be an access point).
If you mixed it up and said PaperUI when you meant to say Basic UI (the user’s interface which is for regular use), you could use either of the apps on Android and iPhone instead.
You are right - I’ve mixed int up. I meant Habpanel or Basic UI, but the first one looks better on 19 inch screen.
This is to present weatcher condition and air quality in the hall of the building. So will be working 24/7.
Wait a minute … there is no need for a desktop environment (understood as a whole set of services running in the background) to run a web browser. There is only X server needed. And maybe a window manager. There are plenty of lightweight window managers out there. You will find more info here: http://www.bristolwatch.com/rpi/xinitrc.htm. They claim that some of them consume around 50-60 megabytes. In my opinion this is worth trying. Of course if You run chromium which requires endless amounts of memory You will fail, but if You choose a lightweight web browser this could work.
You still need X and X requires a lot of RAM all by itself. You can indeed run a browser without the window manager (LXDE, XFCE, Gnome, et al) or using a much lighter weight desktop manager, but you must still have X11 windowing server.
To make it work, you can probably just run Chromium from xinitrc instead of the desktop manager. Unless I’m counting wrong, just xorg, excluding LXDE, is using 630M of RAM on one of my RPi 3s. If I am calculating incorrectly, then it may be using as little as 160M. But given that the RPi 3 only has 1 GB of RAM and OH will need at a minimum half of that. So if we assume another 200 MB gone to run X and the lightest weight desktop manager that leaves only 400 MB or RAM to run everything else.
I don’t have good numbers on Chromium but I do know that firefox is currently consuming over 400 MB of RAM on one of my Linux desktops. Lets say Chromium is twice as effecient in terms of RAM usage (an unreasonable assumption I beleive). That means at best you have to run the whole rest of the operating system in a mere 200 MB of RAM.
So rather than go through this academically, lets just look at how much RAM is free on that one RPi I have that is running X with LXDE. Once I shutdown the Google AIY scripts (the only think I’m running on this RPi, I have 75MB free. That is definitely not enough RAM to run OH.
No matter how I look at it, I just don’t see a way to run an RPi with X11 and still have enough RAM left to run OH.
RPi zero or RPi zero w would probably be cheaper than any Android dongle, particularly if you can scrounge up the SD cards and cables.
How do You measure the memory consumption ? the proper way is to run free command and take the value from the free column of the “-/+ buffers/cache” row.
look at this article: https://flexion.org/posts/2014-03-memory-consumption-of-linux-desktop-environments/ The guy claims that Enlightenment runs with 83MB of memory usage. And the Enlightenment is not the most lightweight. The Xorg process on my machine (ubuntu 14.04) uses between 80-120MB. The memory consumption of the Xorg process will depend on apps that use the X server.
I did exactly that and used htop to find the amount of RAM X and firefox is using specifically.
But its your time. If you guys don’t want to take the advice of those of us who have been there and tried that, its your prerogative.
This just confirms my point though that it is X11 that is the memory hog, not the desktop manager.
On that RPi I have nothing but the desktop manager running. I only interact with this machine through ssh and the only reason it has X on it at all is that is how the Google AIY image came configured.
No, it means that the whole system consumes 83 MB so it leaves more than 900MB for other stuff. I ran openhabian on the CHIP which has 0.5GB of ram and it worked, very slowly but it worked.
And yet, on a RPi running a pretty stock Raspbian with X11 and LXDE and the only other thing it is running is a Python script, which I turned off before I ran free, has only 75 MB free.
And I believe You, but this is not the answer for the OP. Yes the “stock” openhabian installed on the “stock” raspbian desktop will not work. But my claim is that it is possible to run a web browser on the rpi3 with openhabian. My setup (rpi3 + openhabian + some other small services) has 393M of available memory. I can bet that installing on top of that xorg server + some lightweight WM and web browser will work. Maybe I even try it 
I totally agree! It is possible! I have done it (there is a lot of tweaking involved)! Not with openHABian though!
It is foremost important that one can manage the resources well enough!
Just my 2 cents!
Why not connect a Raspberry Pi0W to the display running raspbian with chromium.
$10
