I’ve been trying to learn django on and off for ages now. I usually lose concentration after the first two parts of the tutorial. But this time I had a purpose - the website. I’ve found the best way, for me to learn a new language, is to take a tutorial telling me how to make another project, but apply it to my own project. So I installed the SVN version of django and I’ve zoomed through a lot of django learning now. It’s great. It’s all nicely arranged and modular, which is something I’m liking more and more as my programming skills have developed and perhaps lazyness, when re-using code

I’ve also been using subversion to keep the code organised. I would have used bazaar if there had been a webdav plugin that worked with the current version I have. I suppose I’ll have to wait for intrepid for that then. subversion is serving me well though. I just got to get the person that’s supposed to be helping me to actually help me. Yes, that’s right - I’m looking at you Stephen.

But now I’m moving on to developing an automation application for the time that there isn’t a show on air. This will be similar to Southampton University’s radio station automation system (http://surgeradio.co.uk).

I’m using a combination of python and gstreamer. The feedback so far from the teacher involved, with our radio station, is good. The only problem is the network technician that is a Windows Server user. I think I’m going to have a problem, when I ask for a linux server to host the automation server, streaming, file server, and website. I expect he’ll wonder what’s wrong with his little sharepoint setup, he has going. Hopefully I might be able to do some persuading to get past that, but it’s not going to be easy. I understand the problem that this would cause though. I’m the only one with the skills to maintain the linux server. When I leave next year, I doubt they will have a clue how to operate the server, as I don’t think they have no knowledge of Linux. Anyway, that’ll be fun to try and sort out. Any suggestions?

At the application side, it’s coming along well. I’ve made a website that will allow listeners to request songs to be played. These requests are popped into a MySQL database. From here, my python app checks for new requests after every song. If there is a request, it’ll play that. If not, it’ll choose the next song from a pre chosen list. Nifty, aye?

I was amazed at how quick it was to develop in python, as this is my first real programming project in python. It was so simple to get a basic set up done. I had it done within a night! Jono Bacon’s excellent guide on gstreamer in python helped me well. The app now also has a nice little GUI, made in glade, that’ll help the DJs turn the automation on and off.

For the hardware setup, I’m looking to get the server, that I mentioned, and a few high quality sound cards, that’ll provide balanced audio in and out. I don’t think we’d need much processing power for the encoding of the streaming, as I’ve done a few test runs with my old Pentium 4 clocked at 1.8GHz.

All I have to do is finish it all up now… And perhaps do some of my many pieces of homework!

So Wednesday. An average sort of day, you’d guess. Well, not quite.

Arriving at school, we noticed a large group of people walking around with the head teacher. Entering tutor time we were told that “someone important” was visiting our school today, and there would be camera crews around. Went to the first lesson of double maths. Room change. Fine…

Got to the new room and were told by our maths teacher that there were going to be three people coming to our maths lesson. These three people, announced in this order, were:

• Minister for women Harriet Harman
• Education secretary Ed Balls
• And finally, the Prime Minister

Ok then. Sounds like fun! So we continued on with our maths lesson. Quadratics in simultaneous equations. What fun! We even got a presentation on the computer (that’s my maths teacher trying to show off, I expect). During our lesson camera crews and photographers slowly trickled in to the maths room standing at the back. They were even taking pictures, though no one had turned up yet. What’s all that about?

5 minutes later the door opened and out popped Gordon Brown (followed by the other two of course!). Everyone stared at him amazed that it was actually him. He asked a few questions, such as “Is maths your favourite subject?” and “What do you want to do, when you’re older?”. That must’ve been the quietest my class has ever been. After a while, they began to start talking to him, although it was still quiet. He went to go and talk to people individually while the other two came around too. Harriet Harman came and had a look at my maths book, looked confused, and said she was “crap at maths”.

About 15 minutes passed and they were all pulled out again to move on. Once they left, we discussed what we thought of our prime minister. I thought he looked different to how we see him on the TV. He was older and larger (my maths teacher used the term “cuddlier”) than how he seems on Television.

Ok that’s over… Back to maths! What a lot of homework we get…

More pictures?

Off I went to a Maplin store. You walk into maplin and you are instantly greeted with millions of electronic things, of which I didn’t know what they were. Walking around there, for a while, I discovered some electronic kits. These “make your own” kits are manufactured by Velleman, and I can recommend them.

So after browsing through the many different kits, I ended up choosing a Clap activated switch. Whilst I was there, I grabbed a soldering iron stand, as I already had the soldering iron + solder.

More pictures?

Opening the kit presented me with millions (ok, 20) resistors, and a bunch of other electronic parts. Two days later, and the solder sucker having to be used occasionally, the kit was finished. One thing I forgot to purchase was a transformer to plug it in with. After visiting maplin I came home and found the transformer was faulty. It is one of those changeable voltage transformers. This one, however, would only work when set to 6 volts. After getting a replacement, finding that it was faulty too, buying a different one instead, I finally got the clap switch to work.

And am I surprised that it worked first time? Well… Yes!

And where will I go from here then? Read on…

As I mentioned earlier, I’d like to get into AVR programming. Unfortunately, there is no simple kit, like the Clap switch. The parts that they mentioned I should use, in that Systm episode on AVR programming, are quite hard to find in the UK. You can go ahead and use the digi-key site that Systm recommended. One problem with that though is the postage. £15 for shipping + £5 for handling!

Eeek! After a fair bit of searching, I decided to post a forum thread. The result turned up Farnell. I haven’t found out the postage yet. But I expect it can’t be as bad as Digi-key.

Anyway…

After reading this mailing list post on ubuntu-uk, I was surprised these 3G datacards actually worked under ubuntu. Therefore, I instantly zoomed off to ebay and purchased one for £34 + postage. I made sure it said unlocked in the ebay listing, as I currently have a virgin mobile sim card and didn’t want to waste/switch to vodafone.

So the datacard turned up and I popped my phone SIM in it. Following the guide that was written in the mailing list, I configured it. This was using kppp. So I made everything was in there right and tried to connect. One problem though. Everytime I tried to connect kppp would lock up instantly. “Ah dear”, I though.

After much researching, I managed to set up the datacard using gnome-ppp, which is equally, if not more, easier to set up the datacard in. And here is a little guide I’ll write in full for you…

The guide

The vodafone 3G card. Great little thing. Get the internet almost anywhere!

Now, these vodafone cards seem to be just some re-branded ones. The real manufacture, found from the label underneath, is Novatel Wireless. The model of the datacard is Merlin U630.

Pop the SIM card into your datacard, ensuring that you put it in the right way (I may have been stupid enough to put it in the wrong way ). And then plug it into your computer. First off, it would be quite a good idea to ensure that it was detected by the system. To do this open up a terminal and enter the command dmesg. This should hopefully give you a long list of text, where the end of it slightly resembles this:

[ 124.076000] pccard: PCMCIA card inserted into slot 0
[ 124.076000] cs: memory probe 0xf8000000-0xfdffffff: excluding 0xf8000000-0xfc1fffff 0xfce00000-0xfd3fffff
[ 124.080000] pcmcia: registering new device pcmcia0.0
[ 124.080000] pcmcia: registering new device pcmcia0.1
[ 124.224000] pcmcia: request for exclusive IRQ could not be fulfilled.
[ 124.224000] pcmcia: the driver needs updating to supported shared IRQ lines.
[ 124.268000] 0.0: ttyS0 at I/O 0×3f8 (irq = 3) is a 16550A
[ 124.312000] pcmcia: request for exclusive IRQ could not be fulfilled.
[ 124.312000] pcmcia: the driver needs updating to supported shared IRQ lines.
[ 124.360000] 0.1: ttyS1 at I/O 0×2f8 (irq = 3) is a 16550A


From this you can see the ttyS0 part. This is the name the Linux has given to your datacard. This isn’t really necessary, but it could be useful to know.

Time to install gnome-ppp. Run sudo apt-get install gnome-ppp. One final thing to do in the terminal is edit a setting of ppp in linux. Run the command sudo gedit /etc/ppp/options. That will load up the text editor, so that you are able to change the options. Head to the bottom of the file and add novj to the end on a separate line. Save and close this file.

Head to Applications -> Internet -> Gnome PPP. This will load up the gnome ppp manager. Press the setup button to load up the options for connecting. Click the detect button, so that it can find your modem device, or alternatively choose the name we found earlier (in my case /dev/ttyS0). Even though it isn’t a USB modem select under type USB modem, as I found this is the setting that worked. Set the speed to 460800.

Now, you’re going to need to find your mobile provider’s APN address. I found this website had a bunch of APNs for many different mobile providers. So, as I use virginmobile, I scrolled on down to the virginmobile part and found my APN was goto.virginmobile.uk.

Pop back to the settings for gnome-ppp. Click the “Init Strings…” button. In the 3rd Init string item put the following line of code, replacing goto.virginmobile.uk with the APN for your mobile provider.

AT+CGDCONT=1,"IP","goto.virginmobile.uk“

Once you’ve entered that, press the close button in the Init Strings window. That is the end of the configuration in the Setup dialog also. So go ahead and close that too.

You’re now back to Gnome PPP main screen. If you go back to that webpage I pointed to you earlier, and down to your provider you’ll find a username and password. Copy these accross to the username and password boxes of gnome ppp. If the webpage said (leave blank) next to either the username or password, just put anything in to fill that up, as gnome ppp will not allow you to connect otherwise.

One final part is to add in the phone number to dial. This is, for most people, going to be *99***1#. Now that you’ve entered all the settings needed go ahead and click Connect. Hopefully, through the power of 3G or GPRS, you will be connected up to your mobile network and able to surf the internet.

You may have a few problems with your DNS. You’ll know this if you are not able to load a webpage like google.com normally, but you are able to via http://64.233.187.99/. In which case, I’d solve this problem by using the opendns servers. Head to System -> Administration -> Network. On the DNS tab set your DNS servers to be 208.67.222.222 and 208.67.220.220. After that, you should be able to visit sites easily again.

Now, I think that’s it. If I’ve missed anything please comment.

Bye.

And the fan failing. That was fun. It kept overheating and after much playing around, we found that the fan on the cpu heatsink had died. Shuttle being nice and kind when they designed this heatsink, made a size fan that you can’t get anywhere. Instead, I got a generic case fan and duct taped it to the heatsink! Clever, eh?

So my server. What is it serving? Well, it’s backup server. Thanks to the backuppc package, all the computers will be backed up in my house. Every week a full backup is done. Followed up by a incremental backup each day. Backuppc is also very clever. If there are files that are the same across backups and computers, the file will only be stored once. I can’t backup my whole house yet though. This is because of the hard drive in the server. It’s only a 120GB one. That means I’m currently only backing up one computer as a test.

What else is my server serving? SSH. The first thing I did when I set up the server was install SSH. This is for two reasons. The server is now on top of a shelf somewhere else in the house with only power and an ethernet cable attached. SSH is my means of remote access. The other reason is so I can have a nice SSH tunnel when I go to sixthform in September. No more annoying school filters to me Another part of my SSH server is a key based authentication. I decided that I didn’t really want to put my server out on the internet, if someone was able to bruteforce the password. Therefore, I have set up key based authentication and completely turned off Password authentication.

Quotas. I also managed to set these up. Just as a play around really. It was pretty simple to do:

1. sudo apt-get install quota
2. Open up fstab and pop in the usrquota option to the partitions that need to be quotaised
3. Restart
4. sudo edquota -u username
5. The quota config for that user will show up. Under the blocks and inodes column, you are able to see what the current use of that user is.
6. You are then able to edit the number of blocks (1,000 blocks = about 1MB) that the user can make under the first hard and soft columns.
7. The second quotaing is the number of files which can be set under the second hard and soft columns
8. Save and quit. You’re set!

What’s the difference between hard and soft quotaing you ask? From what I’ve read around the internet, a soft quota is one that limits the user slightly. The user is allowed to go over the soft quota. But only for a limited time, before they have to delete the files. The hard quota is a strict quota. You hit that quota, and that’s it. Delete the file or be able to do nothing!

And of course, to do my bit, my server is folding proteins. Slowly but surely…

I’ve be learning the great web development language known as ruby on rails. I’m not quite a 1337 h4xx0r at it yet, but hopefully one day! Or perhaps not. I’m not a 1337 h4xx0r at php and javascript and I’ve been using them for quite a while now.

Advantages?

I think this ruby on rails magic makes all this web development lark much easier because of the following things I’ve found so far:

Firstly, the “Model, View, Controller” way of running things. Ok. So this wasn’t easy to understand straight away. But as soon as it goes *click* in your head, it sure is amazing. I remember half heartedly trying to learn ruby on rails a while back and gave up pretty quickly because of the confusion from this MVC. If you want to learn ruby on rails, I do recommend getting a good book (I’ll talk about that in a minute), and also making lots of examples to remember what all the different components of MVC do.

Number 2 in ruby on rails features has to be Migrations for databases. Migrations allow you to easily synchronise database changes between developers of the web application. You make a change to the database that needs to be synchronised? Well then you setup a database migration step and the changes will be updated when the developer next runs db:migrate. Another good use for database migrations would be to easily manage the database states between the development and the actual deployment on a server. I can’t see PHP doing that with any great ease.

Number 3? Well… I don’t have a number 3! I’ve only got to page 100 so far. Actually 99. But still!

The elite book

Before starting to learn I spent much time trying to find the best book to guide me through learning the language. After browsing through the surprisingly small amount of RoR books on amazon, I found that the best beginners book is one that goes by the name of “Agile Web Development with Rails”. It’s a bit of a mouthful for a book title, but it surely is a great book. It is very well written and easy to understand.

The book takes you through building a project that is an e-commerce site. I find this is the best way to learn a new language and is what I’ve done for almost every other programming language I’ve learnt. I would have preferred for it to be a more useful project, such as a blogging system or something else. But looking at it now, I can see that an e-commerce system probably contains lots of different concepts that you will learn.

I’ve included a direct link to the amazon page for the book on the right, so if you are thinking about buying this book, please follow the link below to help support the running of my blog!

Having my summer holidays starting early, I’ve got to find things to fill my day with. Yesterday was “make the samba screencast” day.

New format as well. Full 720p HD format and also a little introduction at the start.

Here it is anyway, in all of it’s hd goodness:

I seemed to be extremely slow in making this screencast too. It took me the whole day to make a 4 and a half minute screencast. I suppose. I wasn’t working on it constantly though.

So, in making the screencast I did the following things:

• Planned my general script while running through it with a vm
• Make a little presentation to start off the screencast
• Get the transitions to work just right
• Record the intro + presentation
• Add audio
• Record the content
• Add audio
• Record the ending
• Add audio
• Join it all together

Simple, eh? Not really. I kept bumping in to little problems whilst recording which annoyed me everytime.

And with the audio, if I say one word wrong, that’s it, I’d have to start again. Audacity seems to hate me. If I was to want to have a separate track to record to it would decide that the sound would be all broken up. Annoying I know, but I think I fixed it *after* I recorded all the sound. At least it should be better next time!

And today I found out that I forgot to include a part on changing the samba configuration file.

Oh well. Hopefully more will be on the way soon!

I persuaded my friend to use Ubuntu Linux a while back. So he went and installed it. He found that his wireless network card didn’t work, and there was no way it would work (even under ndiswrapper). So he went ahead and bought a nice wireless card from linuxemporium.co.uk. You’d think that they’d pick one that would work “out of the box”. Well, no! You get this awkwardly written guide (not good for newbies to linux). So I went ahead and re wrote it into simple talk. Great! It worked!

About a month later he decided to reinstall ubuntu and windows so that he could get the partitions right. So he went and did it and began to set up the wireless network card again. This time it didn’t work, even with my simpler instructions. So instead of getting me to help that much he decided he’d just get a nice ethernet cable instead.

Right. So he’s trying to get *everything* to work under ubuntu now. One of those things required his external USB hard drive. Simple you’d think. Plug it in and see it appear on the desktop. Unfortunately not. In this case it was, plug it in and see *nothing at all* happen. So he comes talking to me to ask for help. This is what I found out

• The device was being recognised as sde - from dmesg
• The device was not mounted - from mount
• The device had partitions - from cfdisk /dev/sde

So, I go ahead and tell him to mount the disk manually.

sudo mount /dev/sde1 test

“Please specify a file system type”. Ok then.

sudo mount -t vfat /dev/sde1 test.

“Invalid file system type”. At this point my friend restarted into his windows partition, and the drive worked perfectly. During this time I had a google around and found that there might be an error on the drive. I don’t know much about fsck, but I gave it a go anyway.

fsck /dev/sde
Response: No FSINFO sector 1) Create one 2) Do without FSINFO

Ok then. We’ll press 1 and continue, even though I don’t know what a FSINFO sector is (but at a guess I’d say it is a sector that holds information about the file systems). After that part there were a few other messages like “Free cluster summary uninitialized (should be 10914208) 1) Set it 2) Leave it uninitialized”. We just hit 1 each time and carried on. But at the end of all of that we get a message saying “Leaving file system unchanged.“. I was asking myself why it isn’t saving the fixes, even though I told it to fix it. Ah well. Back to the drawing board.

After a few variations on the fsck command I came up with this nice one:
dosfsck -w -r -v /dev/sde1

So. Ran that. Hit 1 a few times. And tada! All fixed!

And now I know how to operate fsck more! Yipee!

In other news, it’s raining a bit here, and there’s a lot of thunder

/me hides

As you can see, I’m using wordpress, which I found terribly easy to set up. Puts my old WebspotBlogging to shame really.

Ah well