Pi-A-Sketch

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!

Networked scanners are another one of those things that are simply incomprehensibly pricey; a quick search just turned up tens of devices which are selling for more than £900. And you don’t buy ease of use with that money: if you’re working in an office with people who aren’t very comfortable around computers, these machines can be intimidating and difficult to get to grips with.

So Eduardo Luis has come up with a cheap, and incredibly simple (single-button-simple) alternative to the brain-crampingly expensive off-the-shelf networked scanner, and has built a device using a Pi, a couple of LEDs, a resistor, a push button and an old scanner. Pop a document in the tray, push the button, and your document is scanned and sent to email automatically, with no further interaction from you. Here’s some explanatory video: Eduardo goes into more detail on his website.

We love watching you guys come up with ingenious ways of replacing expensive specialist equipment (see baby monitors, time lapse camera rigs, virtual analogue synthesisers – and, of course, the ubiquitous media centres) with the Raspberry Pi. Give us a shout via the Contacts page if you’ve got something similar you think we’d like to feature on this blog.

Adafruit Web IDE

First up, Adafruit’s Raspberry Pi Web IDE is now in Alpha, and they’ve made some improvements which I think you’ll find very helpful. The package now includes:

• Python step debugger
• Node.js update to 0.8 from 0.6 for faster navigation, and page loads.
• Package node binaries with the WebIDE for faster, and easier installs

You’ll need to reinstall to take advantage of the new features.

Web IDE debugger in action – click to visit Adafruit

Crunchies

We’ve been nominated for one of Techcrunch’s Crunchie awards! We’re up for Best Hardware Startup, and you can vote for us here. You can vote once a day; we’d really appreciate it if you could take a minute to show your support!

Pinball

Mark Baldridge is taking a year out between high school and university, and he’s spending that year on hobby projects. This is one of them: a home-made pinball machine with a Raspberry Pi for brains.

Click to visit TechFruits for a tour of the system, and some video

We thought this was a brilliant project. Eben and I have always fantasised about having the time to refurbish an old pinball machine, but we’d never thought of building one from scratch – we’re in awe. Mark is also blogging his progress on his own website – check it out!

Getting Started with Raspberry Pi

O’Reilly have just published a new Raspberry Pi book under the Make banner. Full disclosure: I haven’t actually got my hands on a copy of Getting Started with the Raspberry Pi yet, so I can’t review it here. But I do know Matt Richardson from Make, who wrote it; and I know that he’s a great teacher and demonstrator, and a very engaging writer, so I feel pretty confident in telling you to go and check it out. When I last spoke to Matt, he mentioned that the book would contain a chapter on using the Pi with Arduino, which was something we didn’t include in Eben and Gareth’s The Raspberry Pi User Guide (the two books should complement each other nicely, if you have room on your sheves) – Matt’s book also contains a chapter on working with webcams. Click the image to visit the Getting Started with Raspberry Pi Amazon page.

Raspberry Jam

Alan O’Donohoe led another London Raspberry Jam last week. We’re really excited to see that his message is getting out: every one of these events seems to be larger and more diverse than the last. (Alan has started holding the events at weekends, which makes them much more accessible for kids.)

Around 70 children, parents and teachers came to learn what they could do with a Raspberry Pi at a number of workshops – we sent Rob Bishop, our roving engineer, to join in. Alan has a short post about the event, and a photo album you can have a flick through. He’s looking for sponsorship so he can make the jams even bigger and better – if you can help, please email me at liz@raspberrypi.org, and I’ll pass your message along.

Train times

Finally, here’s a project from Gareth James, a man who lives five minutes from the train station but always seems to get there just as the train is leaving. He’s made a very handsome picture frame which displays train times, powered, of course, by a Raspberry Pi. You can find out how he did it on his website.

Just before the New Year, we saw a lot of links in the tech press to a very neat hack using a Raspberry Pi as an Apple AirPlay receiver. The project had so many news stories written about it before I’d spotted it that I didn’t put it on this blog at the time because I thought most of you would have seen it – but do go and have a look if you’re a iTunes person (and have managed to get your head around the new layout of the library in iTunes 11 – my own failure to have got accustomed to it so far makes me worry about brain softening).

If you’re not an iTunes person, and you’re looking for an open alternative, you could do a lot worse than use Stephen Phillips’ UPnP/DLNA streaming method, which uses Android phones as remote controls. Your music lives on a server, and streams to your home speakers via the Pi. You can also play your music by streaming it to any of those phones, whether you’re at home or out gallivanting.

If you already have at least one Android device and some speakers, Stephen reckons that your outlay, including the Pi, should be about £45 – contrast this with the cost of a similar (closed) setup using Sonos hardware (today’s price on Amazon, with a sale on, was £230). Audio quality should be as good as – or even better than, depending on what your home hi-fi setup is like – an off-the-shelf solution using AirPlay, Sonos or Squeezebox, despite coming in at a fifth the price.

This is something I’ve been meaning to set a Pi up at home to do for ages (a little thing called work has got in the way). If you want to make your own streaming setup, Stephen has easy-to-follow instructions on his blog.