The Raspberry Beer’o’meter

https://blog.senx.io/the-raspberry-beerometer/

by telecoteco • 7 years ago

36 17 7 years ago

blog.senx.io

jchw3• 7 years ago

FWIW I think a more reasonable goto (than a browser) for a Raspberry Pi dashboard would be something along the lines of Qt QML, maybe with Python Qt bindings if you don’t want to write C++ code. It’s not really lightweight, but it can interface with the bare KMS EGL (no Xorg needed,) is hardware accelerated, and performance was acceptable when I last tried it on, I believe, a Pi 3.

gwillz• 7 years ago

I was going to suggest the same but with LinuxFB. I don't believe it's hardware accelerated though.

https://doc.qt.io/qt-5/embedded-linux.html#linuxfb

Qt is fairly popular in the embedded space. I'd bet the support and robustness is quite good.

jchw3• 7 years ago

Oh sure, you could go direct to fb. I think the default builds on Raspbian already support the KMS EGL path, though, so in theory it just gives you extra performance at little cost.

inferiorhuman2• 7 years ago

I've been monkeying with a Qt/QML app recently on my desktop with an eye towards deploying it on a Pi based thing. One thing really stood out: the Pi support kinda sucks. Specifically, the binary situation is not great and Qt is a bit of a beast to compile (plus I'd have to setup a Linux VM to cross compile in a reasonable amount of time).

Raspbian comes with a fairly outdated version of Qt inherited from Debian, and there are no precompiled EGLFS binaries that I can find. Even the Qt folks don't distribute an installer. I could understand a complex beginners guide[1] if this were lower level stuff. It's not.

1: https://wiki.qt.io/Raspberry_Pi_Beginners_Guide

kingosticks• 7 years ago

I had the same experience a couple of months ago. I spent a weekend banging my head against a wall following their documentation to cross-compile for pi3. Turns out it was out of date and there were also a couple of bugs. Since then they did fix one of the issues I reported. The other one already had a long open issue with no resolution (at the time). But I've lost all interest in trying again for the foreseeable future and I wouldn't recommend the experience.

Fnoord• 7 years ago

recently

How recent? Debian's latest stable, Buster, got released a couple of months ago. Raspbian's rebase on Debian Buster is recent, like a good month ago. Raspbian should sport Buster's Qt version.

Const-me3• 7 years ago

I wish someone would implement a bare metal DRM/KMS/GLES backend for https://github.com/AvaloniaUI/Avalonia, e.g. based on NanoVG C library for vector graphics and fonts. .NET core runs way faster than JavaScript in browsers, and C# is much higher level than C++ people use with QT.

kekekeks• 7 years ago

FYI: https://github.com/AvaloniaUI/Avalonia/blob/master/src/Linux...

pp-ir2• 7 years ago

Qt + Warp 10... Maybe it could be possible !

But the kiss approach was great here. WarpScript includes all you need to render text, vectors, images... The limit is that I cannot use the touchscreen.

Thanks for your replies everyone !

dangxiaopin2• 7 years ago

A word of caution if you are starting a small LCD project: the framebuffer approach is dead on Linux. The new approach is DRM (Direct Rendering Manager), that allows partial LCD updates from userspace. See

https://www.raspberrypi.org/forums/viewtopic.php?t=128736

https://github.com/notro/fbtft/issues/432

jchw3• 7 years ago

Even if this is true, isn’t that about drivers and not interfaces? Perhaps I am wrong but I was under the impression that the framebuffer userspace device worked on DRM-based drivers still, just it didn’t use fbdev internally.

dangxiaopin2• 7 years ago

I am not 100% sure either, but I think /dev/fbN does not exist without a fb driver. DRM uses /dev/dri/renderNNN

pp-ir2• 7 years ago

With this little SPI screen, there is no GPU behind, so no way to use DRM. If you want to run X, you also need to use framebuffer turbo driver. So everything goes through the framebuffer anyway.

The fun here was to use only Warp 10 database on the system, the only time series database that has built-in image creation function in the language. Normal use is to build heavy dataviz on the server, then return a base64 encoded png.

mmjaa• 7 years ago

I was once in the hackrrspace in Pristina, Kosovo, where ingenuity and DIY-culture reign supreme.. the group has a beer-brewing project, which turns out to be quite popular, and as a result the freshly brewed batches don't last long.

So they did the hacker thing and wired up the keg to an EPS8266, and gave everyone an RFID chip with which to gain their weekly beer rations.

I found this immensely amusing. Truly a wonderful hackrrspace .. if anyone ever gets a chance to visit Pristina, check them out .. and bring them some hardware to play with, while you're at it ..

The Raspberry Beer’o’meter

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