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Comment by dividuum | Hacker News Reader

Since parent ask for a comparison with Lua and the Pi: I'm running a digital signage service (https://info-beamer.com/hosted) that uses a custom minimal Linux (~35MB) on the Pi and a program written in C that is scriptable in Lua. One of the key features is hot reloading of code (and visual assets). Thanks to the flexibility and robustness of Lua that works incredibly well: You can even push new code to the central website using git, it instantly deploys it to connected devices and they reload their code. If done correctly you can update the content and logic your displays without any interruption. The C code is pretty robust for a few years now and never crashes or leaks memory.

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That's really fun! Back in another lifetime (2006) I co-founded a kiosk company. I wrote a platform with a C core and Lua on top and used it to manage some pretty big kiosk networks, as well as handle all of the "server side" logic of our apps: pathfinding, hardware integration/card readers, printing, etc. . . I definitely miss working with Lua and C. We used Flash for the UI on most of those machines and our shit looked _sooo_ much better than anything else on the market at the time. Funny enough I used the bindings for SVN to programmatically handle pushing out updates, I imagine git would have been much more pleasant.

Anyway, thanks for the trip down memory lane.

This is great. How is the business side of it?

Looking good. Once customers realize that our platform is far more powerful that just throwing a browser at everything, they get really excited. You can fully automate everything with the API, build perfectly smooth 60fps content and even play synchronized content across any number of screens. And a lot more. Coupled with the low cost and the reliability of the Pi, it really looks great. Still, getting the word out is difficult as the Pi is still considered a toy by many.

Just a couple of thoughts/questions if you don't mind:

- How's the supply-chain side of things? For a while, vendors would only sell one Pi at a time, if they had stock at all. Have you had any problems with that?

- Why do your customers know or care that there's a Pi inside? It seems like an implementation detail that only a select few would ever think to ask, unless you're telling them. "COTS ARM Cortex A53" would likely be enough to make most people's eyes glaze over before digging enough to discover that there's a "hobbyist" board inside.

Edit: I looked at your website and get it :). You're selling hosting, not pre-packaged devices. That's really interesting!

Supply for the "normal" Pi has never been a problem AFAIK. Only the Pi Zero has these problems. But as you noted: We don't sell prepackaged hardware: Only the software and service. Shipping/Warranty/Return handling seems pretty complicated and not worth the hassle (at least for now). Instead we made the installation as simple as possible and as a result users only have to unzip a single ZIP file to an empty SD card and put that in their Pi. So far even to most non-technical users managed to do that.

That's awesome! Congrats! That's a really cool niche, and it sounds like you've executed on it in a pretty interesting way. Although I haven't done it recently, I did a fair bit of Lua embedded in C in my M.Sc. and found it to be a really smooth way to add a ton of power to C code without needing to do a bunch of work.

Just saw the demos, and they look great. Back when I ran this sort of thing I moved from Pis to Android boxes for our own in-house system for SVG support (https://www.flickr.com/photos/ruicarmo/albums/72157643937892...) but often wished I’d had a simpler, more efficient setup.

How good are the Lua bindings for OpenGL ES? Are they as nice as Löve? I tried https://www.mztn.org/rpi/rpi_ljes.html once, but it was a bit fiddly.

info-beamer pi (the software that runs in the Pi and drives the output) doesn't expose OpenGL directly at a very low level. Instead it provides a higher level API to draw and move images, fonts and videos around (see https://info-beamer.com/doc/info-beamer#referencemanual for the complete API). So it's indeed similar to Löve. As a programmer you really don't have to know OpenGL to get anything done. Right now info-beamer pi doesn't have SVG support but images and even videos get you pretty far for most effects I can think of.

That sounds like such a perfect fit for Lua. We used it to the same effect in gamedev.

Coroutines are also amazing for sequenced AI routes.

Coroutines are also useful for some of the visual code I wrote: You can have functions that run through an animation, yielding for every frame. Or of course you can handle loading, displaying and teardown for content in one function. Pretty handy.

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