“What’s innovative about a video wall?” I hear you cry. “We’ve all seen them. Big…walls of video. Been done for years.”
We’ve said many times that the single most innovative thing about the Raspberry Pi is its price. $25 or $35 gets you something that would have cost you four or five times that amount before the Pi arrived on the market. This means that you can save large sums of money in some applications, especially in applications where you need to buy a lot of separate devices. A video wall requires one device per screen, and another to drive them all together. I’ve seen video wall solutions being run with all kinds of devices at the back end; previously one of the cheapest ways to do this was to buy a Playstation for each of your screens – obviously a much more expensive (and power-hungry – you’re spinning a lot of hard drives all day to get the result you want) way to get what you’re after.
Plus, of course, our HD video capability’s really great.
So Alex Goodyear at Culham Centre for Fusion Energy has put together a really elegant video wall, supported by a group of Raspberry Pis. Energy consumption and cost are both reduced enormously, making video walls like this much more accessible to enterprises which don’t have huge funds, like museums, schools, shops, galleries and offices.
You can use different sizes and orientations of screen in the same set-up here; you can use the screens to show one large moving image or many small ones; you can display static content like photos or web pages alongside moving content on the same wall.
Read more about what Alex has come up with at CCFE – we’re looking forward to seeing more of these in the wild!
Francois Dion is someone I exchange emails with every now and then. He’s the guy behind the excellent (and multilingual: check the site for posts and tutorials in English, French, Portuguese and Spanish) Raspberry Pi Python Adventures blog. He’s a hackspace member from North Carolina, and he’s been giving lecture-demonstrations of the Raspberry Pi (and lasers) to interested groups, and promoting it in schools locally. Our community would be nothing like as large and colourful as it is without people like Francois, who put their own time and energy into spreading the word about Raspberry Pi with no support from us at the Foundation – we are very, very grateful to Francois and all the other people out there who make so much effort on this project’s behalf. (Seriously; next time I’m in NC, I will be making a studied effort to fill Francois full of gratitude-symbolising food and drink. In as many languages as I can muster.)
Francois has been making something really cool.
Is it e-ink? No…
A little while ago, he attended a session at PyPTUG (the PYthon Piedmont Triad User Group) about motors. “We did a lot of stuff with motors. DC, servos, H bridges, PWM and steppers. It was a very dense 3 hours. We covered a lot, and it was a lot of fun.” He went away to think deep thoughts about what sort of fun you could have with a Pi and some stepper motors; and he came up with the Pi-A-Sketch.
The stepper motors you can see here have the same diameter as the shaft of the familiar twirly knob they replace.
Equipped with an Etch-a-Sketch, some stepper motors, a battery pack, a Pi, an 8-channel Darlington pair and some leds, wires and headers, Francois has made a device that uses Python to draw all those things on an Etch-a-Sketch that, as kids, had us throwing the things at the floor in frustration at the uselessness of our fat thumbs. Horizontal, vertical and diagonal lines? No problem. And with a bit of help from Bresenham’s algorithm, you can draw circles too. (Eben has a funny story from when he was about 11 which involves Bresenham’s algorithm, a BBC Micro, the days before the internet, inter-library loans and the month’s wait he had to endure before he was able to get his hands on the very simple information he needed to draw a line on the screen. Ask him about it if you see him and you need a reminder of how lucky we are to have the ability to look this stuff up online.)
“What practical use is all this?” I hear you mutter at the screen. Well, so far it’s gone down a treat at talks Francois has been giving about the Pi and programming. This sort of demonstration is exactly the sort of thing that captures the imagination, and opens up the eyes to what you can achieve with a little programming and a little solder flux. Here’s something familiar that you can pass around an audience (thanks to that Kodak battery pack), made magical with the addition of a little science. We love it, and so did the audience at the IEEE in Winston Salem, NC, where Francois first showed this project off.
Instructions on how to get the hardware set up are available at Raspberry Pi Python Adventures, and Francois will also be writing a post about the Python that you’ll need to get things working in the next few days. (I’ll update this post when he’s ready – in the meantime, you can find the source code at Bitbucket.) Thanks Francois; we look forward to hearing more from you!
I am kind of in two minds about posting this little bit of frivolity from Jeremy Blythe: it’s the sort of ingenious, silly project that made me laugh when I saw it and I wanted to share it with you; but it’s hosted on a Raspberry Pi, and Raspberry Pis are not built for the sort of traffic that the things that get posted here tend to get. In short, once I’ve hit the publish button, it’s likely that this particular project will get knocked over – so if you can’t see it, wander over instead to Jeremy’s Raspberry Pi page for more inspiration, and try again later.
What Jeremy has done here is to use a Raspberry Pi to stream content from a webcam on a webpage. So far, so run-of-the-mill, you say. But the content he’s streaming is the output from a 7-segment LED display, also driven by the Raspberry Pi, which gets its instructions via the Raspberry Pi’s network connection from people like me with nothing better to do on the internet.
The entry from Santa Ana, California at the top (and the choice of number) is me. I'm in America again, bigging up the Raspberry Pi to anyone who will listen, and making Raspberry Pis 5000 miles away display numbers *because I can*. Click the image to visit the cam and to add your own number.
The webcam won’t be up all the time (Jeremy is using his Raspberry Pi for other things too), and, as I mentioned above, it’s unlikely to be up at all if everybody reading this tries to visit it at the same time. You can read more about the setup on Jeremy’s blog. Jeremy: apologies for accidentally DDoSing your Raspberry Pi. I did it with the best of intentions.