Raspberry Pi time!

Although I have had the pi out and working once before, it’s been a while and there’s a new distribution out for the software, so it was like starting all over again: the first thing I needed to do was to download and unzip the new distribution (Raspbian wheezy) from the pi website.  This needs to be copied onto an SD card before you start.  You have to use a disk imager to set up the SD card, it can’t just be copied over, but I’d already downloaded a free disk imager ready.

pi with case

pi with case

The operating system for pi is a linux distribution, with a graphical interface very like Windows available. It also comes preloaded with several pieces of software such as Python and Scratch, making it very fast to get up and working for programming purposes.  It took about 20 minutes altogether to download the software and copy it onto the SD card ready for use, and then I could start plugging things in.

The pi comes with two USB sockets which are usually taken up with keyboard and mouse, and as the operating system is installed onto an SD card which needs recreating for a new setup, this time I was also trying out a powered USB hub, so that I can save any work I do onto a separate memory stick rather than on the SD card.  The Pi itself isn’t powerful enough to run a hub, so it has to be one with its own power supply.

I hit a major problem when connecting the screen – as I explained in an earlier post, I need to use an adapter to connect my screen to the pi, and it had a rather troublesome connection, but eventually we managed to get it working.  So I had the pi up and running, with powered hub running keyboard, mouse and memory stick, and with a cable draped across the room to the router to give an internet connection as well.

I was disappointed to note that this new distribution seems to have a lot less than the previous one in the way of preloaded software, but the essentials are there – web browser, python 2 (with pygame) and python 3 (without pygame), plus Scratch.  Squeeze is also listed, but didn’t seem to load up.

There is also a folder of python games, taken from the book Invent With Python, which I copied onto the memory stick to bring back to my main machine and look at.

The browser seemed to work with no problems at all, and it was as easy as plugging in the cable and typing in a web address to get online with the Midori browser, so that was the basics up and running, although I couldn’t see how to access the memory stick directly from applications such as Scratch – my husband said something about mounting the drive, but I felt copying over is enough for now, until I get to the point of using the pi properly and having files worth saving directly onto the external drive.

I feel now that maybe I’ve reached the point where I need to start looking carefully for instructions, either via the MagPi magazine or some of these books that have sprung up about the pi, in order to take it any further.  Scratch and Python are fine with no issues for me, but the operating system is a little unfamiliar for anything outside the very basic and I’m not confident enough to go poking around, downloading stuff and installing it without advice.

I do believe the pi is a wonderful gadget, but as yet I don’t think I’ve identified its full purpose – as a really cheap machine available to encourage kids to play with programming, it’s great, but apart from its price it doesn’t offer that much different from a desktop machine. I understand you can use it for input and output devices, rather like the arduino, but that again is something that would need research and setting up, although it does seem to me that one major advantage for the pi apart from price is the physical size of it and that seems to be begging to be embedded in some sort of system.

I think it’s time to go off and do some research into what people are using the pi for, and what it’s capable of!

PS the case is great for protecting the pi as it sits on  my desk – I found it on my husband’s desk (around his pi in fact! shh!)

More about the Pi

Pi with memory card

The raspberry pi is a small computer.  It was released in April this year, and the current release is considered the developer’s release.  The intention is to produce a version for education in the near future (it should even have a case!)  Its operating system is stored on an SD card, which means that it’s easy to switch versions for different builds.

It has two USB slots, which are typically used for keyboard and mouse, an HDMI slot for the monitor and uses a low level power supply. (More technical details here; it’s not my intention to go into too much technical stuff, I just want to get exploring the practical side.)

HDMI to VGA M/F adapter

I needed one extra piece of kit – an HDMI to VGA M/F adapter.  That was enough to adapt my current monitor lead to fit the pi.  A powered hub is needed to run any extra devices, as the pi itself doesn’t put enough power through to power anything else.

That’s as much as I needed to know in order to get prepared for when my pi arrived in June. It had been ordered on the first morning that orders were open, but it took a while for the supply to catch up to the demand.

pi parcel

A neatly packaged raspberry pi

I followed the instructions on the website, bought a 4G SD card and downloaded the debian squeeze distro that’s recommended for beginners, then used a card imaging utility to create the image on the SD card.  Just copying the file over won’t work: my first lesson in the more technical aspects needed to get the pi up and running, and to be honest it was very simple.

All I need apart from the monitor

Then it was plugging everything in, turning it on and watching as streams of white text appeared on my black monitor.  Not yet ready for a command line interface, I started up the GUI.  This is linux, but so very similar to windows that there was no issue at all.  The first session was really to check the pi was working, and to see what was on the system.  I recognised Scratch, and was pleased to note that python was also installed.  A few minutes was enough to figure out how to write and compile a python program or two (“hello world”).

I haven’t yet plugged in the ethernet cable – I still need to figure out whether I can wangle another one from the router or whether I’ll need to unplug my main box’s connection.  I’m lucky enough to have a two monitor set-up on my desk, so can run both pi and the PC side by side, and I don’t really want to lose the internet connection on the PC as it’s handy to be able to look up details as I work on the pi.

So having established that all was working correctly, I packed it all carefully away again, ready for the holidays when I’d have more time to work on it.

A summer of fun

Time to do more with this blog, I think, and I have an idea just what I could do.  Two parcels of electronics.  Two different ways to get technical.  It’s time to delve under the covers and see what goes on, to create my own stuff instead of using what’s created by others.

raspberry pi and assorted bits

The Pi itself is the smallest item on the table, I think!

Raspberry Pi

The first to arrive was the raspberry pi – a computer the size of a credit card.  Some declare it to be the saviour of computing, others are not so sure.  I intend to use it to develop my programming skills.  Yes, I can do it on my PC just as well, if not better, but that’s not what this project is about.  The pi is the circuit board bit just behind the keyboard – dwarfed by the other components, even the mouse!  Hard to believe that this is a full working computer, but then apparently the chip on our chip and pin bank cards hold more processing power than they used to take man to the moon!

My pi has a 4G SD card loaded with Debian Squeeze, a linux distribution, and has several programs ready for use, including Scratch and python.  I may also use some other software development tools over the summer, for example smallbasic/visual basic, yousrc and MIT app inventor, which won’t yet run on the pi, but which still offer opportunities to design software and are reasonably accessible to younger programmers.  Greenfoot is another programming environment, an introduction to java, which is being ported to the pi.

Arduino starter kit

A box of goodies – no idea what most of them are, let alone what they do!


Then just today the arduino starter kit arrived.  This I’m less sure about – my experience with electronics is next to none, although I have played with Lego Mindstorms before now, so the principle of connecting components to a control system is not new. Still, it comes with a manual, and there’s always the internet, and I’m looking forward to finding out how to use this thing.