July | 2012 | Raspberry Pi

Android 4.0 is coming!

Update: those of you looking to play with Android on Pi in advance of our source code release might want to check out the community Razdroid project, which last month produced its first non-accelerated port of Gingerbread on top of the publicly released VideoCore binary.

Naren has been working on a port of Android 4.0 (Ice Cream Sandwich) to Raspberry Pi, and as you can see from the screenshots and video below, he’s been making great progress. Hardware-accelerated graphics and video have been up and running smoothly for some time; AudioFlinger support is the only major missing piece at the moment.

This implementation uses a different kernel and VideoCore binary image from the one available on GitHub, which is why we’ve been keeping quiet about it so far. We’re investigating the feasibility of converging the two code lines to produce a single common platform as soon as we can, at which point we hope to release the sources for you to play with.

Controlling a 7-segment display from half a world away

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.

Raspberry Pi smart glasses translate in real time

Will Powell read about Google’s Project Glass, and decided he’d have a go at a DIY attempt to try to achieve something similar. And what he’s come up with is downright remarkable. Here’s his automatic translation system, which uses a couple of Raspberry Pis, a 3d headset, some microphones, a TV and an iPhone to display real-time subtitles in your glasses as you have a conversation.

Attack of the Raspberry Pi

The Raspberry Pi’s effect on creativity among kids still has the capacity to surprise us. Owen Herbert wrote and starred in this short horror movie alongside his Raspberry Pi, directed by big brother Luke. I am removing the SD card from the slot of my Raspberry Pi before I turn the lights out tonight.

Meet the Raspberry Pi – download the e-book!

The cut-down version of Meet the Raspberry Pi, written by Eben Upton, our Executive Director, and Gareth Halfacree, is now available on Amazon as a Kindle e-book. It’s only£3.29.

This is the shorter, cut-down version of the book, which is to be followed shortly by a much longer book with more tutorials, more programming, and more physical computing (and longer versions of the existing chapters). This shorter version is ideal for beginners, and will talk you through setting up your Raspberry Pi from scratch, and get you to a position where you can start using your Raspberry Pi like a pro. If you are a more advanced user, you may prefer to wait for the full version of the book to come out – I know the publishers are scrambling to get everything finished, so it shouldn’t be long now.

Big thanks to Gareth and to Eben, and to everyone at Wiley for all their hard work.

A Raspberry Pi, hosting…Raspberry Pi

Liz: Here’s a guest post from our old friend Pete Stevens, who runs Mythic Beasts, the hosting company that keeps this website on its legs even though more than 100,000 of you visit every day. He’s in charge of a Raspberry Pi which has some of the best connections in the world. And we don’t mean social connections: read down to learn more. (This post was first published at http://blog.mythic-beasts.com/.) Thanks Pete!

Raspberry Pi hosts itself

We’re now running a mirror for the Raspberry Pi download server and the Raspbian apt repository on a Raspberry Pi.

The first problem was obtaining a Raspberry Pi as buying one was tricky: firstly the online shops were down, then the queue for a Pi was rather long. As any banker can tell you, occasionally crime does pay, so I abducted Mooncake, a cat which owns Liz and Eben. I then ransomed the feline back in exchange for a Raspberry Pi.

[Liz interjects: and Mooncake hasn't got over it yet. She now hides every time someone with a beard visits the house.]

The hardware setup starts with a power supply with an IEC14 connector connected to the masterswitch for remote power cycling. This PSU connects to a powered USB hub, with a USB lead connecting to the power connector on the Raspberry Pi. The Pi is then connected back to the hub on the data cable with a 1TB USB external hard disk attached to that. There’s a 100Mbit ethernet cable which connects up to the core Mythic Beasts network and out to the Internet. Technically the switch port on the other end is 1Gbit but the Raspberry Pi isn’t fast enough to use that.

The yellow fibre in the background is a very large Internet exchange with over a terabit of bandwidth. The Pi isn’t connected directly (that’d be too stupid even for us) and the packets travel from the Pi to the exchange a couple of feet away via another building. However with LONAP and LINX within 2ms and AMSIX a mere 8ms away it’s still rather well connected.

The software setup on the Pi is fairly straightforward. We started with the Debian squeeze image, ssh/apache enabled, munin enabled (graphs here). We’ve changed the password (obviously), the ssh keys (shipping the same ssh key on every OS image isn’t optimal), and moved /var/www and /var/log to the USB disk so as not to fill the SSD card. rpi-update was needed to make the USB/network setup stable under load as the initial image kept crashing. We also set the RAM split to 224MB for Linux as we really aren’t using the GPU.

It’s up and running both IPv4 (93.93.128.128) and IPv6 (2a00:1098:0:80:1000:13:0:3), as the core Raspbian server is also running IPv6 and the main Raspberry Pi server is also IPv6 at present; this machine has seen more than 50% of its traffic over IPv6. I suspect this will change as people download images from it though.

At present the Raspberry Pi is devoting nearly half its CPU to drawing munin graphs so I need to benchmark the new Raspbian distribution to see if the hard float debian build improves the anti-aliasing, as presently all the calculations are done without using the FPU on the arm core in the Pi. Benchmarking suggests that we can deliver 35-50Mbps of file downloads reasonably comfortably at present.

Is this sensible? We’ve had a few customers ask us if the Raspberry Pi would be a sensible device for hosting on as it’s very cheap and very low power. Unfortunately it’s also very slow for this kind of application and the supporting hardware is very bulky. The i7 quad core Mac Mini occupies less space than the Pi + hub + disk + PSU, uses about fives times as much electricity, costs about five times as much once you include the supporting hardware but is hundreds of times faster. So revolutionising the hosting industry isn’t going to happen with the Raspberry Pi, at least not until they build a PoE one with gigabit ethernet and more RAM.

[Liz: you may be waiting some time for that, Pete. I'd stick to the Mac Minis.]

It’s not currently sensible to do this with shelves full of Raspberry Pis because the performance per Watt isn’t good enough. But we’re working on it.

Thanks go to Liam Fraser and Mike Thompson for adding us to the official mirror lists for the Pi and Raspbian. Additional thanks go to Eben and Liz for paying the ransom fee of one Raspberry Pi in exchange for the safe return of Mooncake.

Mike Cook’s Magic Wand

Mike Cook, electronics Superman, swapped some emails with us after we last posted about one of his projects. Eben and I both wanted to talk to him about a feature from Mike’s Body Building column in Micro User from 1989, where Mike made a magic wand that wrote letters in the air.

BBC Micro User, July 1989

I read the magazine and lusted after the thing; but at my girl’s boarding school in rural Bedfordshire, where we didn’t have an electronics lab (although we did have a huge domestic science suite), mercury switches and leds were about as easy to get your hands on as unicorn poo – you could buy a kit from the magazine, but I’d spent all my money on bubble gum and cello rosin. Eben had a very lucid memory of that particular column too, and hadn’t been able to get the parts either. We both mentioned that it was our favourite design from the Body Building column while thanking him for the projects he’s done with a Raspberry Pi so far. (Mike, ever self-effacing, says that similar projects have been done a million times since then, but he does believe that this was the first time such a thing ever appeared in print.)

So Mike went quiet for a couple of weeks, and then came back with this: a magic wand controlled by his Raspberry Pi. I have been scampering around the study like a schoolgirl since I got his email. He has, as always, written exhaustive instructions if you want to make one yourself, complete with software you can edit on your Raspberry Pi, tips on font design, and notes about the legality of mercury switches (which, as it turns out, are still available and can be used legally as long as you’re not going to sell your magic wand).

Of course, these days, we’re probably supposed to call this a persistance of vision project. But as far as I’m concerned, it’s still a magic wand. Thanks so much, Mike; this is quite a lot like having a rock star you worshipped as a kid re-write a song for you. And I’m sorry about the beating your shoulder took during testing.

A housekeeping note: I’m away for a couple of days travelling to and setting up for ~~DEF CON 20 in Las Vegas, which we’ll be attending as vendors~~. Bugger. Unforeseen circumstances and all that; we are no longer attending, because a problem with liability for Nevada sales tax came up at the last minute. Really sorry if you were hoping to see us.

The Raspithon’s finished!

Ben, Luke, Ryan and Edward coded for 48 hours solid. And they created a very neat-looking game called Rasperroids; demonstrated to everyone (except that one guy) who dropped into their channel just how much fun coding can be; learned a lot; and raised more than £500 for the Raspberry Pi Foundation, for which we’re enormously grateful.

Ben play-tests the finished Rasperroids

You can download the code they wrote over the 48 hour marathon at Github.

I was pointed on Twitter at some thoughts from Richard West about the project, and what it means in context with concepts like paired programming and Agile (stuff that I suspect the Raspithon guys hadn’t ever encountered; they just sat down and worked out a collaborative programming model on their own). Richard’s post is well worth a read.

We are impressed, inspired and really touched by Ryan, Edward, Ben and Luke’s application, skill and thoughtfulness. Well done, guys – let’s do it again next year!

Raspithon continues: live feed undaunted by DDoS attacks

I’ve been checking into the Raspithon (this link is for a live feed) every few hours (time for sleep aside), and it’s surprisingly engrossing watching the video stream and chat channel as Ryan, Luke, Edward and Ben develop the game they’ve set themselves 48 hours to write. I heartily recommend it. They’re nearly a day into the project now, and last time I looked all kinds of interesting physics to do with bullets and explosions was going on. I don’t remember having that much trigonometry when I was 12. You can read more about the project here.

The guys have been suffering a DDoS attack which has taken their website down. I remain absolutely bemused that there are people out there who think doing such a thing to kids who are raising money for a charity is smart or funny. I could say a lot more about this, but I suspect that those of you who are reading will say it for me in the comments. Sam Nazarko, who is developing Raspbmc, a media player for Raspberry Pi, has also been a victim of a particularly nasty DDoS attack; the site you’re reading this on has been as well, but we are lucky enough to have a superb host in Mythic Beasts, who move very swiftly to address these problems when they occur and are surprisingly nice about stuff like this when it happens.

Fortunately, the Raspithon live feed is hosted elsewhere, so all they’ve lost is the wrapper that the feed lives in; the Raspithon itself is still going on, and the game (which I did advise them not call Rasperroids, but was overruled on) is developing nicely. Hanging out in the feed gives you a fascinating look into what it’s like to learn a new coding language (if you’re wanting to learn yourself, or if you’ve forgotten what it’s like). And if you’re there at the right time, you may find Eben, me, Alex or one of the other Raspberry Pi developers in the channel too; and we like it when people come along and engage us in conversation, be it about pizza or Python. You can find the feed at http://livestream.com/raspithon - Ryan et al hope the main site at www.raspithon.org.uk will be back later.

Pibow

If you’ve listened to interviews we’ve given about the general fantasticness of our community, you’ll have heard us mention more than once that that very fantasticness has, on occasion, made us alter the direction the Foundation has planned to take things in. (Raspbian, a Raspberry Pi optimised distro which came out of the community, and which you should already have upgraded to because it’s 40% faster that Squeeze, is a great case in point.)

What's that, you ask? Keep reading for an explanation.

One of the most surprising about-turns for us came over casing. We had solid plans on getting an official case designed, once we’d sold enough Raspberry Pis that we could afford the injection moulding for large numbers, and selling that alongside the Raspberry Pi. But a cases ecosystem appeared almost instantly once the Raspberry Pi was in the community’s hands, and people started to get very excited about making their own, either for home use, or to sell. And we like that, because we believe the world runs on entrepreneurship, and hope that from small case-companies great things will grow. We also like the fact that the Raspberry Pi acts as inspiration to kids to go and make their own; physical making as well as digital hacking is something we really want to encourage. (The educational release will come in a very bare-bones case, but we hope that one project that schools will take on as soon as they get them will be getting kids to make their own cases, either using that bare case as a base for their design, or making new ones from scratch.)

Pibow set up

So we’re not giving any one case official Raspberry Pi Foundation status. But if you’re still looking for one and don’t own a lathe and a laser cutter, the closest you’re going to come to such a thing is the Pibow from Paul Beech, who designed our logo, does our letterheads and business cards, and is currently working on the Foundation’s new web site design. (Paul posts as @guru here and on our forums.) Lots and lots of you send Eben and me your cases in the mail (soon we will need a larger house to keep them all in), and I should make it clear that I’m not featuring Paul’s here because he works with the Foundation, but because his case is one of the most solid – absolutely no rattling – and best-looking cases I’ve seen yet. (He’s donating a proportion of the profits to the Raspberry Pi Foundation, the GIST Foundation and his local Access Space, which we’re very grateful for.)

There's even a clever slot for GPIO ribbon cable if you're doing a spot of physical computing with your Pi.

Paul introduced me to a prototype Pibow at Games Britannia a few weeks ago. About eight seconds after he removed it from his bag, a small girl barrelled up to us and said: “Is that a Raspberry Pi case? It’s LOVELY. Where can I get one?” He then showed us a newer prototype in the pub after the Cambridge Raspberry Jam last weekend, and a cluster of grown men holding pints said: “It’s FANTASTIC. Where can I get one?”, so I reckon he’s got most bases covered.

I agree with the little girl. It’s lovely. You can get one from the Pibow website, I think it’s the nicest retail case I’ve seen, and I want one. Hint hint, Paul.