Well, this is unexpected, and we’re all feeling a bit overwhelmed. Raspberry Pi won the Best in Show award for Hardware Design at the ARM TechCon yesterday. Apparently, a chunk of perspex is currently being engraved, and will be making its way to us soon.
Here are a couple of pictures from the day, very kindly sent to us by Bac’an, one of our forum members. We are especially delighted by the one suggesting that Eben himself has won Best in Show, as if he was a pedigree dog. It’s not as if he has a particularly glossy pelt, although he will sit up and beg if you do the right manoeuvre with a Jaffa Cake.
Raspberry Pi stand - that's Avatar running at 1080p on the monitor above the alpha board.
Eben, bright-eyed and bushy-tailed. (A bit like a well-dressed spaniel.)
Here’s a very in-depth interview with Eben about the project from the ARM TechCon 2011, which was filmed yesterday. It’s 12 minutes long, and it answers a lot of questions you might have about the project. We are particularly charmed by the interviewer, who initially thinks the project is called Raspberry Pee.
A quick post to let those in and around Toronto know that if you’ve got some free time on Friday, Eben will be giving a talk about Raspberry Pi at the Free Software and Open Source Symposium (FSOSS) at Seneca College, York University. He’ll be giving his presentation at 2pm. If you want to attend, be sure to buy your ticket online rather than at the door – it’ll cost you much less than buying one when you arrive. I’m afraid we weren’t confirmed in time for you to get an early-bird ticket, but if you’re a student you can get in for CAD $40. General admissions are CAD $85.
This means that Eben’s going to have to leave the ARM Techcon in Silicon Valley pretty sharpish on Thursday afternoon after his presentation there, so if you’re one of the California attendees who has told us you want to meet him, nobble him immediately after his talk!
Many people have asked us whether it’s possible to hand-assemble a Raspberry Pi. While the use of fine-pitch BGAs and PoP memory make this impossible, I thought you might like to see how one of my home-made prototypes of a $25 computer looked back in 2006, before I gave up on DIP chips, through-hole components and veroboard.
Veroboard and PCB versions of the prototype
These boards use an Atmel ATmega644 microcontroller clocked at 22.1MHz, and a 512K SRAM for data and framebuffer storage. 19 of the Atmel’s 32 GPIO lines are used to drive the SRAM address bus. To generate a 320×240 component video signal, the Atmel rapidly increments the address, and the data lines are fed via 74HC-series buffers to a trio of simple summing-point DACs; during horizontal and vertical blanking, it is free to perform other operations. Here’s a video of the device in action.
Not quite Quake 3, I’m sure you’ll agree, but maybe familiar to fans of David’s 1987 classic Zarch. In the end, I felt that much higher performance, and the ability to run a general-purpose operating system, outweighed the benefits of home assembly, but it’s still a neat design. Those of you interested in the gory details can download Easy-PC schematics and a PCB layout here.
There has been a lot of speculation about the power supply design for the production Raspberry Pi devices. The alpha boards use a pair of switch-mode power supplies to generate 5V and 3V3 rails from a 6-20V input on a coaxial jack, and LDOs to generate the low-current 2V5 and 1V8 rails for the analog TV DAC and various I/O functions. This is a flexible and power-efficient design, but suffers from two drawbacks:
Expense. The two switch-mode parts and their accompanying inductors add roughly $2 to the cost of the device.
No support for 5V input. To correctly generate the 5V rail, more than 5V has to be presented at the input.
After a lot of experiments and spreadsheet work, we finally settled on an LDO-only power supply design, with a fixed 5V input, and the 1V2 core voltage generated directly from the input using the internal switch-mode supply on the BCM2835 die. We have chosen a 5V micro-USB jack to supply power to the board, for two reasons:
Ubiquity. Micro USB has been chosen as the GSMA’s Universal Charging Solution, so we expect AC adapters with this connector to be cheap and plentiful.
Voltage assurance. Unlike coaxial jacks, we know that we’ll be receiving 5V over this connector, which we can pass on unregulated to HDMI and USB devices.
Model B owners using networking and high-current USB peripherals will require a supply which can source 700mA (many phone chargers meet this requirement). Model A owners with powered USB devices will be able to get away with a much lower current capacity (300mA feels like a reasonable safety margin).
Chris Tyler, from Fedora and the Seneca Center for Development of Open Technology, has some great video for us today: a few apps running on Raspberry Pi under Fedora. Work’s being done on a Fedora spin for Raspberry Pi at the moment, but things are looking good even without optimisation. Check out the video, and visit Chris’s blog when you’re done. Thanks Chris!
Rob Hague, a good friend of the Raspberry Pi Foundation who has been hacking on an alpha board in his spare time, has a gorgeous little demo of VNC remote desktop running with the Raspberry Pi as a client. Rob’s blogged about it on his own website, so I won’t repeat what he has to say here – go and read it when you’ve watched the video.
Rob sometimes posts on the message boards here as robhague, and you can reach him on Twitter or via his own website if you want to harangue him with any questions. Thanks Rob! It looks like we owe you a beer.
Providing nothing spectacularly newsworthy happens between now and 10.30pm in the UK, tonight’s Newsnight on BBC2 will be talking about computing in schools. David Braben, one of our trustees, has been interviewed by the program, and some other friends of the Raspberry Pi foundation have been talking to them too (including Alex Evans of Media Molecule, who is one of the giant brains behind Little Big Planet, and was directly responsible for Eben and me meeting each other back when we were all at university together – although I doubt he mentions that on camera).
Updated to add: here’s the whole clip, along with the studio discussion that bookends it, on YouTube so folks outside the UK can watch it.
There’s some lovely footage of the Raspberry Pi running Scratch, which I hope gives you a feel for the sort of educational application we’re excited about putting on the device!
Collating all the results was like herding cats. We ended up adding some of the developers to the voting panel to try to break the deadlock, only to find that they were equally indecisive – lots of those involved insisted on voting for five or six logos at a time. An additional hiccup introduced itself when one of the finalists emailed us to withdraw, kicking the counting off again. We’re sorry about the delay: I hope you’ll agree that the logo we chose was worth it!
Congratulations to Paul Beech, whose logo had the largest number of votes from the panel because of its graphical simplicity, its adaptability and ease of reproduction (it works well in only one colour as well as in the three-colour version you see above, and doesn’t have any holes of the sort that would prevent us from using cutouts), and the fact that it looks darned friendly and delightfully raspberrysome. The raspberry here is actually a 3d buckyball, which is a nice reminder of π. The designer points out that a buckyball has 32 faces, and that 11 are visible in the logo – the Raspberry Pi has a 32-bit processor and an ARM11 on board (someone got awfully lucky with the numbers here).
Thank you to everybody who participated. We had so many entries that it made judging very difficult, and we were overwhelmed by the quality of what came in. We’ll be posting some of the runners-up here next week.
While you’re waiting for the logo contest results, here are some gorgeous demo videos from the Qt team to keep you busy. You get to see the Raspberry Pi decoding some very handsome stuff at 1380×768 as it generates and moves particles, as well as seeing the code it’s running while the demonstrator talks about the performance he’s seen from the board. Make sure you watch all of them – they just get better. Best of all, these demos just worked straight out of the box.