Raspberry Pi – A new era in computer programming for school kids?

It seams like everyone is trying to get hold of a Raspberry Pi, but what exactly is it and what is all the fuss about?

What is the Raspberry Pi?

The Raspberry Pi is a small computer about the size of a credit card. The initial version is only available as a bare motherboard, but future versions will be available with a case.

The Raspberry Pi is similar in processor and memory to some smartphones and includes a HDMI (and analogue) TV output as well as USB connectors and on one version a Ethernet network connection.

It is powered using a mobile phone charger plug.

An important aspect of the device is that it is inexpensive. Starting at just $25 for the basic model making this affordable for schools and pupils alike.

The Raspberry Pi as an education tool

The aim behind the Raspberry Pi is to get school children excited about computers and to help create computer programmers for the future.

This is similar to what the BBC Micro and similar home computers did back in the 1980s. Back then computers were simpler and made it easy to tinker and learn how to program. There was no risk of breaking anything as if anything went wrong you just powered it off and started again.

These days computers are complex and expensive. Many computers also restrict what you can and can’t do with them through closed source software and other technical restrictions (eg. games machines). Even if you could tinker with them then many parents would not like to risk their children damaging the home computer that the family has become so reliant.

By making the device so cheaply it means that pupils can have their own computer that they can tinker with and the worst that could happen is that they need to re flash the SD card back to it’s original settings. As it can plug into a standard TV (in many children’s bedrooms) there is no need to take turns in using the computer monitor or main computer.

Powered by Linux

The board is supplied without any operating system, but images of the open source Linux operating system are available. This has to be installed onto an SD card which is plugged into the slot on the board.

Linux is an ideal operating system for the Raspberry Pi as it is a freely available popular operating system. Crucially it is also open source, so rather than being restricted to creating programs on top of the operating system, more experienced programmers can get into the basics of the code that make it run and improve on the operating system.

Incredible demand

The initial launch is not for schools but for hobby enthusiasts. This will help to build a community of ideas and support which will hopefully help encourage and support the adoption within schools.

There has been a huge demand for the initial release of 10,000 boards. The Raspberry Pi was available to order from 6am on 29 February. The websites of both retailers that are selling the devices have struggled under the huge demand for these which far outstrips the initial batch from production.

New stock will be arriving in due course, but this is a frustrating wait for availability. Unfortunately there have been a lot of negative comments on Twitter etc. It’s completely unfair to place criticism at the Raspberry Pi Foundation, whose website continued to work fine (in reduced launch day mode). Whilst the suppliers websites it is very hard to deal with the kind of demand that was thrown at them, although disappointingly the RS website only allowed for showing an interest rather than taking pre-orders.

It’s obvious that this is in high demand and has all the potential to be a huge success.

What’s next?

The real challenge going forward is getting the Government to listen and getting a good IT curriculum into schools that can turn this huge potential into a great learning tool. Teaching children that a computer doesn’t have to run an expensive proprietary operating system, and that learning to write software can be fun.

Once I get hold of one I’ll be posting a proper review and will be providing details of my own projects that I’m looking at running on the Raspberry Pi.

Read more »

Review of Devolo dLAN 200 – Ethernet over power

I have already written a review of an earlier model of the Devolo Ethernet over power adapters.

These devices provide an ethernet network connection by passing the signal over the mains electricity cables within the house. These are useful for devices that don’t have built-in wireless support (eg. blu-ray players, Internet enabled TVs and games consoles). The reason that I use these is because they are not susceptable to wireless interference which causes problems with my miniPC which is located at the opposite side of the house to the wireless router.

My earlier adapters had a maximum bandwidth of 15Mbps, whereas these newer ones are designed for up to 200Mbps. Devolo also make ones that can work at up to 500Mbps but as I it is being used to connect between switches designed for 100Mbps there is no benefit in having a faster connection.

The devices under review are the basic models which consists of a plug-in module with a RJ45 ethernet port and a setup button. There are also version with pass through sockets (so as not to block the socket from other use) or with a built-in wireless access point, which are more expensive.

The devices are avaiable in a starter pack with a pair of modules, or individually.

The configuration of the powerline devices is much easier than the earlier version. Instead of having to connect to the devices to pair them, it is now a case of pressing the configuration button on each device. It is still possible to configure using the supplied software, but that is now optional.

There is still a supplied software CD which includes the software for Linux. It needs to be compiled but it’s a simple process if you have the development packages installed.

In use the connection seams to be reliable. I have not got any accurate benchmarks but it does feel noticeably faster than previously.

These are a good solution to provide network connections without needing to run cables around your house and avoiding problems with wireless signal drops or interference.

Read more »

Simple electronic circuit for kids – low light sensor

My 6 year old daughter is learning about electricity at school, so I thought it was a great opportunity to show her some electronics whilst she was interested.

We decided to create a low light sensor, as the circuit is quite simple, but it is still something that looks quite good when she shows it off to friends and family.

This is the finished product:

Whilst most of the wiring is just a case of plugging directly into the breadboard, it did involve some soldering which I let my daughter have a go at. It did involve some hand-holding (literally) as both the soldering iron and heat gun (used for heat shrink insulator) get very hot!

Read more »

Getting wireless to work on Xubuntu / Ubuntu linux with broadcom based firmware

In the past I have had problems with getting wireless working on Linux laptops. I thought this had been fixed with more recent distributions, but in some rare circumstances there can be problems.

In this case I have an old laptop that I have set-up for my son to use. It’s ancient compared with current hardware, but is still able to run a less demanding distribution such as Xubuntu. It installed OK with and older version of Xubuntu, but with 11.10 it said “Requires Firmware”.

Checking it’s a Broadcom mini-wireless card

The first step is to identify what wireless chipset is installed. In my case a Dell mini-pci wireless card, which uses the Broadcom chipset. To check this run the lspci command from a terminal:

$lspci | grep Network
02:03.0 Network controller: Broadcom Corporation BCM4306 802.11b/g Wireless LAN Controller (rev 03)

Note you still use lspci for a pcmcia card.

Assuming this says Broadcom BCM43??? we can proceed, if not then you may have to look at configuring the card manually using ndiswrapper and the Windows drivers, but that’s beyond the scope of this.

Install the drivers

To install the drivers run the following from a terminal. You need to be connected to the Internet when this is run using the onboard Ethernet card and a cable direct to your router.

sudo apt-get install firmware-b43-installer

This will download the firmware from the Internet and install the appropriate driver. You should then be able to select the appropriate wireless network from the normal network list.

Conflicts with other wireless packages

If you have the broadcom-sta-common package installed it blacklists the b43 driver which is required for wireless.

To fix – edit the file /etc/modprobe.d/broadcom-sta-common.conf
delete (or comment out with a #) the line. If this file does not exist then move on to the next step.

blacklist b43

Then to force the module to load during boot edit /etc/modules
add a line with


b43

It should now still work after a reboot.

Read more »

Extended review of Asus Transformer Eee Pad

I have already written a initial review of the Asus Eee pad transformer TF101. The first review was written when I had just received it. I’ve now had time to put it through it’s paces and find it’s good and bad points.

Android tablet

Android is a Linux based operating system specifically designed for use on smartphones and touch screen tablets. It is currently the most popular smartphone platform (December 2011) and is a great success on tablets.

The EeePad Transformer is one of the most popular Android tablets so far.

The tablet came with Android version 3.2.1. It is due to have an upgrade option to the latest Android (4 – Ice Cream Sandwich). Whilst Asus haven’t provided an exact date for the software upgrade indications are that this will be mid February 2012.

In use the tablet is fast, looks good and is packed with features as well as access to over 400,000 applications through the Android Marketplace.

Browsing experience, including websites with Flash!

The default browser is based on Google’s Android browser. When first launched it offers the chance to download Flash from the Market (free download), and is then a fully functional browser with flash. As this is a mobile browser some sites show the mobile version of their site. This is normally designed for smartphones and is usually better to click on a link to view the normal desktop version of the website. You can also change the browser settings so that it appears as a normal desktop browser which is perhaps the better option for a large tablet.

There are other browsers available from the Android Market. The Firefox browser is worth considering as it has an export to pdf option which can be useful for printing (there are other ways of printing, but I’ll discuss that later on my blog). Firefox does not however work with flash so it’s worth having both browsers installed and switching between them as required.

The one thing I do miss in the Android browsers is a spell checker. Firefox has had one in its desktop version for some time, but it is not included in the Android browsers. If you don’t use the keyboard then the Android keyboard helps with spelling anyway, but not with the EeePad Transformer keyboard.

As I’ve mentioned before having flash available on a tablet is essential to me. The ipad / ipad2 etc do not support flash and as a result is very much a restricted browsing experience.
I use flash a lot, particularly when using my tablet with my children. Importantly my daughter’s school sets homework using Education City, which cannot be completed without Flash. Also my children like to play many of the games and activities on the CBeebies website.
For me Flash allows me to access iplayer and other video based sites that use flash based video players.

The future is almost certainly going to be html 5, but today Flash is still far more prominent and tablets that don’t support Flash (eg. iPad / iPad2) are very restricted.

Not quite a netbook – or is it?

With the tablet docked onto the optional keyboard, then Asus claims that it then doubles up as a netbook. At first I was going to write here that I didn’t think the EeePad compared with a netbook, but after thinking about it, it is more the case that some of today’s netbooks aren’t really what a netbook was supposed to be. Let me explain…

I have a Asus Netbook, which is a 10″ high spec netbook with built in hard disk drive. The netbook runs a full version of Ubuntu Linux and is in all intents a small version of a standard laptop. But that is not what a netbook was originally supposed to be. The original nebooks had little in the way of internal storage and were designed to access most applications over the network, hence the net in netbook. In that case the docked tablet is still far more versatile than a netbook was intended, but they are not the same as the mini-laptops that we currently call netbooks.

Rather than trying to be a full laptop computer the Android operating system has applications designed to make the most of the touch screen. In the future as laptops have touch screens as standard we will start to see laptops become more finger friendly (and we are starting to see that with Ubuntu’s Unity already), but for now the applications designed for Android are more appropriate than trying to use a “normal” desktop operating system, although this does make some things feel a little more restrictive (with no right click and big buttons with reduced menu options).

If you need to be able to run the normal desktop applications on a small laptop then a netbook will work quite nicely (especially with a lightweight Linux distribution such as xubuntu which is fast and powerful), but if looking for something that has easy to use applications that work well with a touch-screen then an Android tablet is better. The EeePad is the latter, but with the advantage of a dockable keyboard it provides a good compromise.

I touch-type which is fairly straight forward on the docking keyboard, but is not quite the same as using a netbook. I have to disable the trackpoint when doing a significant amount of typing as it’s easily knocked, but there’s a specific button that makes that easy. The keyboard can be docked and undocked at will without needing to suspend the tablet in anyway, just make sure you are not writing to the SD card or an external usb drive when undocking.

Linux, but different – Android Marketplace

As a Linux user I find many of the applications on the Android Market place a bit of a disappointment. There are thousands of applications which is good, but most either include adverts or charge. Windows users will probably feel at home reaching for their credit card every time they want a new application, but as a Linux user I expect lots of quality applications for free.

It’s not that I think all software should be free (in financial terms). I have bought some software for my Linux computer as well (notably Crossover Office and Subsonic) although even then to a good extent these are mainly free (as in freedom / open source).

There are other programs that I expect to be closed source, such as games. From a Linux perspective there is so much good quality free (open source) software that software has to be exceptional to expect people to pay for it, whereas some applications on the market charge for even very basic software.

Even open source software needs to make money (although typically less than commercial software) and a simple solution to funding is something that could perhaps improve many open source projects. Ubuntu has now added a lot of pay software to the Ubuntu Software Centre so perhaps this is the sign of things to come in general. We are also used to seeing advertising when visiting web sites without which many websites (including my own) could not afford to run. Perhaps one of the things about this being a commercial operating system with commercial applications rather than one based around the community and open source.

As long as there is some good free and open source software then I think both can live side-by-side, but some of the commercial software is just not up to the standard I have come to expect.

Specifications and build quality

The specification of the tablet is pretty good. It has a fast processor and the system shows that in use. It has 16GB of internal memory, but this can be supplemented by a microSD card in the tablet and a standard SD card in the dock. The standard SD card will be particularly useful for photographers or home movie makers as it compatible with most digital cameras and camcorders.

Build quality is good. It feels sturdy and the dock is well designed (although sometimes takes a couple of attempts to align correctly when docking).

There are 2 USB ports, but these are in the dock. There are no native USB ports in the tablet itself.

There is a HDMI port that can be used to connect directly to a TV which is useful for showing off your photos or for watching videos on a HD Ready TV.

Charger and battery life

Charging is done using a USB plug-in transformer and a proprietary charging cable. The tablet can be charged from a computer USB, but only when the tablet is switched off and even then very slowly. The charging cable is very short and makes using it whilst plugged in almost impossible. Using a standard USB/USB2 extension cable from the supplied charger will not allow the tablet to charge. Instead you need to get a USB3 extension cable (such as this blue USB cable from Amazon.co.uk ). Earlier buyers of the Asus EeePad transformer reported that you couldn’t get a replacement cable if the supplied one broke, but fortunately these are now available directly from Asus (£29.99 for charger and cable).

Battery life is very good. I haven’t timed the exact length of time we get out of a battery, but it is several hours. There is a second battery in the docking keyboard, when connected to the keyboard then the keyboard battery is used in preference to the tablet. The dock cannot charge the tablet unless plugged in, which could have been a good feature although perhaps not particularly efficient, but just needing to have the keyboard attached to extend battery life is not too bad. The only thing is that there doesn’t appear to be anyway to see how much charge is left in the keyboard. Instead Android just reports the charge of the tablet which remains constant until the keyboard battery runs flat.

Successor – Eee Pad Transformer Prime

The Assus EeePad Transformer Prime is the latest model. It is not yet widely available in the UK, but is available through Amazon UK – Asus EeePad Transformer Prime TF201. The Prime follows the same concept as the Eeepad transformer TF101, but has an upgraded processor and was one of the first to get an upgrade to the latest version of Android (version 4 Ice Cream Sandwich).

Summary

Without the keyboard dock the Asus EeePad is an excellent Android tablet. Looks good, works well and will run Android 4.0 (Ice Cream Sandwich) when an update is ready. As such it is a powerful tablet. The only thing lacking on the tablet itself is a usb port. At the moment the only thing USB is used for is plugging in flash drives, but with Android 4.0 there is the potential for support for additional USB devices. This is not however an issue if you add the docking keyboard.
The EeePad transformer is currently the only tablet to have a docking keyboard that converts the tablet into a touch screen netbook type computer.

For me this was the only tablet I really considered. It runs Flash (which is why it had to be Android) and the keyboard is particularly useful when blogging etc. The full size SD card and support for external disk drives is also particularly useful as a photographer. The only negative thing being the charging cable, which was solved with a £4 USB 3 extension lead.

If you have a bit more money to spend then the Assus Transformer Prime has an even better spec, or if you don’t need the keyboard then Samsung have some other particularly good tablets that you could consider. Bluetooth keyboards are available for other Android tablets, but they don’t allow for on they knee typing as easily as the EeePad docking keyboard does.

Read more »

Dell laptop Inspiron 15R N5010 – first impression

After my previous laptop (HP DV6200 ) ended up as a giant paperweight I’ve now bought a new Dell Laptop. I wasn’t sure about buying a dell after myprevious bad experience with the Dell delivery and helpdesk, but this laptop was the best I could find for the budget available. Fortunately it arrived quickly with no problems this time.

I’ve only had the laptop a few hours so this review is based on first impression with the laptop.

Processor and graphics card

One of the reasons for choosing this laptop was that it includes the new Intel i3 processor which is replacing the previous generation of laptop processors. In the past I’ve gone for AMD processors, but for now Intel does appear to have the edge on performance and value. I expect AMD will overtake again in future, but for now I went for Intel.

This laptop also includes a dedicated ATI graphics processor rather than the on-board graphics on most laptops. In the past I have always bought computers with dedicated graphics, mainly to help with performance when video editing. Dedicated graphics do add a lot to the cost of the laptop and as the processing capacity of laptops is now so fast so I think I could have managed without the dedicated graphics processor. This laptop cost £70 more than a similar laptop with on-board graphics, but it also had a bigger hard disk and more memory which tipped the scale in favour of the more expensive laptop.

This is one of the cheapest laptops to include both the i3 processor and dedicated graphics which was the main reason for choosing this laptop.

Laptop screen and keyboard size

The laptop has a screen size of 15.6″ which is slightly bigger than my previous laptop, but feels a lot bigger. Dell have managed to fit this into a laptop that is only a tiny bit bigger than the HP laptop.

The bigger difference is in the keyboard as the Dell has managed to fit a full keyboard with numeric keypad which occupies virtually the full width of the laptop, whereas on my previous laptop there was no numeric keypad and a large boarder around the keyboard. The keys don’t feel as well shaped as on the HP which feels a little difficult when touch-typing, but I expect it’s something that I’ll get used to after a bit of use.

Unfortunately the Dell does not have any of the backlit multi-media keys across the top of the keyboard instead using the function key with the Fx keys on the keyboard.

External ports and networking

There are the usual VGA and audio ports with an HDMI port for connecting to a HD ready TV. There are 3 USB2 ports and one shared eSATA/USB port. There is also a SD card port.

There is also 100M Ethernet network port as well as Wifi wireless and bluetooth.

There is no PCMCIA / PC Card or ExpressCard slot. These provide a means to add additional connections and are mainly used to provide additional connectivity in the form of USB / Firewire or networking. I suspect most people do not use these slots when installed, but I have used them on older laptops where they have been very useful.

There is no Firewire (iLink / IEEE 1394) port. Firewire was a popular way to connect to camcorders in the past, but has been dropped in favour of USB 2. My recent camcorder has USB 2 connections, but I also have an older camcorder which is Firewire based with a lot of old videos. Unfortunately with no Firewire or PC Card / Express Card slot there is no way of connecting my older camcorder to the laptop.

Windows 7 operating system

The laptop came with Windows 7 64bit pre-installed. This appears to be much faster than Windows Vista, but then that’s not saying much as Windows Vista was incredibly slow and the processing power of this laptop should be quite capable running everything I’ve tried so far.

The Windows Experience Index score is 5.9 with the RAM, graphics card and hard disk transfer rate all having 5.9 subscore.

There are no Windows recovery disks supplied, but the Dell DataSafe application can be used to create recovery disks.

Unfortunately like Vista it still doesn’t run some of the software that I had bought for Windows XP, but I expect to be mainly running Linux anyway.

Installing Linux – Kubuntu 10.10

I installed Kubuntu 10.10 linux onto the laptop. The final release is not due to be released for a few days so I used the Release Client version. The install went straight forward. There was only one issue in that the HDMI driver was selected as the default audio rather than the internal audio driver. This was easily changed and will hopefully be fixed by the time the final version is available this weekend.

Impression so far

So far I’m pretty impressed with the laptop. The only disappointment so far is the lack of Firewire or card expansion to allow a Firewire adapter to be installed. Fortunately I have a desktop machine (although very old) that can be used to capture the video then transfer it to the laptop.

I haven’t really given it anything demanding to do yet, but I’m confident that it’s going to be up to most tasks.

Read more »

MP3 downloads from Ubuntu One – Linux

It’s been a while since I last bought music online, but I wanted a new Album for my daughter so that she can practice a song for a pantomime she’s dancing in. I thought I’d give the Ubuntu One music store a try.

When I first bought music online there was limited choice of retailers and I went with Apple iTunes. Unfortunately theiTunes files included DRM and were in a proprietary format so were unsuitable for use in Linux or on MP3 players without breaking the DRM. Fortunately I believe all the music stores have realised that they were losing customers by forcing DRM on the consumers and so most are available without DRM now. iTunes however has retained it’s proprietary format, so whilst not having to crack the DRM the file still needs to be converted to a more appropriate file for use in Linux or on MP3 players.

As a result of these I used Amazon.co.uk MP3 downloads for a while. Amazon uses MP3 format which is available on most systems (subject to patent, which I believe has now expired in most countries) which is available on many operating systems and devices. The problem with Amazon is that, whilst they created a Linux client to download the music with, it is only available for 32bit operating systems (most modern computers are now 64bit, although some still install 32bit operating systems) and they haven’t updated the client since the version for Ubuntu 9.10 (now a year old with 2 new versions of the operating system since then), so unfortunately I’m not able to use it on my main laptop (more about my issues with Amazon MP3 client on Linux).

I predominately use Ubuntu so the Ubuntu One MP3 store seamed a logical choice. I use Rhythmbox as my music player which is fully integrated with the Ubuntu One music store along with Jamendo and Magnatune. Buying new music is similar to other integrated music stores in that you can browse / search for available music, add the downloads to your basket and then provide credit card details. The only pre-requisite is to sign up for a Ubuntu One account, in my case an existing Launchpad account.

Rather than downloading direct to the computer the file is first copied to your Ubuntu One account, which means that the music is made available to every computer logged in to Ubuntu One which is particularly useful if you have more than one computer you want to play the music on. This also means that, unlike other MP3 retailers I’ve used, there is a backup of the music and it can be downloaded again in the event that the files are lost of corrupted. This is a great feature and means that Ubuntu One leads in terms of functionality.
At the moment Ubuntu One is only available for Linux, but a Windows client is being developed and should be available in beta soon. As these are MP3 files they could be downloaded on Linux and then copied onto Windows.

More about Ubuntu One

Ubuntu One is primarily a web based online backup / file sharing tool. As standard 2GB of disk space is provided, with more available for a very reasonable additional charge. It also offers contact synchronization and music streaming to iPhones or Android based mobile phones, which is a bit more expensive.
Ubuntu One also include contacts, file and bookmark synchronisation. With a Windows client this will be a good replacement for Dropbox, although I’ll be sticking with Dropbox for the Windows compatibility for now.

Read more »

Mobile broadband on Ubuntu Linux – O2 ZTE MF100

I’ve already provided details on how to get O2 Mobile Broadband Pay As You go on Ubuntu Linux with Huawei E160. I have now got a new dongle created by the ZTE Corporation known as the ZTE MF100 HSDPA USB Stick.

The process to get this new dongle working is just as easy as with the Huawei E160. Which is to say it’s not completely automatic, but very easy if you have these instructions. The reason for this is that O2 changed their login details since the first generation of mobile broadband dongles, but Ubuntu still uses the old settings.

Here are the details again – with step by step instructions and relevant screenshots. This has been tried on an Eee PC running Ubuntu Netbook Edition with the ZTM MF100, but it should be similar for other Gnome based distributions and other broadband modem dongles. Note if using a provider other than O2 (Orange / Vodaphone / T-Moble / 3 etc.) then the specific settings will be different. Hopefully the configurations for these is already correct, but I haven’t tried any other networks.

Previously I obtained these details from the dongle as it automounted as a virtual CD drive. I couldn’t find any filesystem to mount on this new modem dongle, but as I’d saved the details from last time I used those instead.

Although the modem dongle is detected it doesn’t start the mobile broadband wizard. To start this right click the networking icon on the task bar and choose “Edit Connections”.

Select the Mobile broadband tab and choose add, which will launch the Add Mobile Broadband wizard.

Select the appropriate modem “ZTE WCDMA Technologies MSM” and choose next.

Select the country United Kingdom and Mobile Broadband provider – O2.

Choose the appropriate contract “Pay and Go (Prepaid)” and choose forward.

The form will be pre-populated with the out-of-date information which needs to be changed.

Change the values as follows:
Number: *99#
Username: o2bb
Password: password
APN: m-bb.o2.co.uk
Note that the word ‘password’ is used for the password.
Although this sounds like a security problem this is just used because the PPP protocol requires a password to be sent. The real authentication is done based on the SIM card inserted into the dongle.

After applying the changes right click on the network connections icon on the Gnone top menu bar and Enable Mobile Broadband.

Then left click on the same icon and choose the profile that was created earlier “O2 Pay and Go (Prepaid) 1″.

The network connections icon will pulse for a few seconds whilst it connects and assuming there is sufficient network coverage it will then connect.
To purchase credit you then need to visit: https://mobilebroadbandaccess.o2.co.uk/.
You will need your mobile phone number (ie. the virtual mobile phone number associated with the mobile broadband SIM card) to purchase credits.

Read more »

Wireless networking – Wifi slow or broken – try changing channel

In the good old days of wireless networking the world was a wonderful place. You bought a wireless router plugged it into your broadband and it just worked. There was an issue of not enabling security, but that just made it easier for others to borrow your network (good or bad depends upon your personal opinion).

The problem is that now everyone has got these your network connection may not be working quite as well as it did before. I noticed this recently when my wireless network at home slowed down to the point where it was unusable taking a second for a single PING (tiny bit of information) to fly over the airwaves. This is the second time I’ve encountered a problem of this type (the other with a friends computer) and I expect this is going to be a bigger problem in future.

The reason for these problems is that the network range that is being used is quite small and with lots of other people installing wireless routers the number of people trying to use the same frequency goes up resulting in lost information and a slowdown. In the case of a friends computer the network connection completely refused to work.

Fortunately if you know what to look for the fix is quite easy, but it may only fix it until the next house decides to go wireless and you end up with the problem again. Anyway here are the details of how you may be able to fix a wireless problem related to wireless network conflicts.

In this case I am actually using a wireless access point (WAP), but wireless routers are more common and are more likely to be in most homes, so I’ll refer to it as a router, but it’s similar for a WAP as long as you can connect to it via a wired connection. First you need to connect to your wireless router. If you have a wireless problem then you probably can’t do this via wireless so you’ll need to use an Ethernet networking cable.

Most modern wireless routers use a web-browser to configure so you then point your webbrowser at the address of your router. This is normally the default route so if using Linux you can use
route -n
and look for the entry 0.0.0.0 which in the example below connects to router 192.168.1.2
0.0.0.0 192.168.1.2 0.0.0.0 UG 100 0 0 eth0

Windows users can use ipconfig and the address is shown as the default gateway:

ipconfig
Default Gateway . . . . . . . . . :192.168.1.2

You then plug this into your browser and you should get to a page for configuring the router (see below).

You will need to supply the router password to make any changes. This may be blank, or specified in the user manual or on a sticky label attached to the wireless router.
Then look for the option that specifies the Channel or the Wireless Channel and you should be able to manually select a different channel (you should have 11 to 13 options depending upon the router). You can find an unused channel by using a WiFi scanner application, but you could just use trial and error. You may need to try a few to find one that's not being used, but hopefully that should be enough to fix the wireless problem for now.
There are only a few channels, but as wireless normally only extends as far as a few houses it's not normally a problem finding a spare channel. I suspect it may be a problem for some people living in flats or apartments where there could potentially be lots of wireless signals in a small distance.

Read more »

Belkin N Wireless Router F5D8236UK4 802.11n cable router and 4 port switch

I’ve been having some problems with my wireless Wi-Fi network connection at home for the last couple of months. Most of the time the network works fine, but occasionally the network slows down to the point where it becomes unusable. This happens mainly in the evening and I believe is due to interference from a neighbour’s wireless network.

At first I found that I could get around the problem by changing the wireless channel on my Belkin Wireless Access Point / Wireless router which worked for a while, but the problems came back again and again. The impact varied between what computer I was using and seamed to be particularly bad on my Dell Inspiron 15R laptop. The distance between my wireless access point (WAP) and my computer didn’t make much difference either.

My wireless access point was a Belking 802.11g 54mb device and as my laptops now have 8.2.11n 100mb built in networking I thought it may be worth trying with a new wireless access point. I therefore bought a Belkin N Wireless Cable Router with integrated 4 port switch. The upgrade in bandwidth / speed is not a big issue, the main use for the network is to share the broadband connection which is at 10mb much less than the wireless network. I do use the network to create a backup copy of my photos which will benefit from a speed increase. Ths version is capable of speeds higher than the standard 100mb, but that is a draft standard and I have not tried that functionality.

Note that the Belkin N Wireless router is available in two types. One referred as the cable version is for use with cable broadband where there is a cable modem (also useful where used on an internal network port as in my case) the other is the ADSL version which includes a built in ADSL modem where the broadband is supplied as ADSL over a standard phone line (using ADSL splitters).
If connecting directly to the Internet connection then Virgin Media cable customers will normally need the cable version, whereas BT / Sky customers will normally need the ADSL version:

• Belkin N Wireless Cable Router
• Belkin N Wireless ADSL Modem Router

The Belkin N Wireless Cable Router was reasonably priced (around £ 40). Although it comes with a setup CD for Windows I performed all the configuration from a Linux laptop that I connected directly to the wired port on the router. To connect was as simple as connecting to the laptop and then pointing the browser (Firefox) to 192.168.2.1. Note that this may be the more common 192.168.1.1 on a new setup / connected directly to the broadband cable modem, but in my case I had connected it to my home network which was already running on 192.168.1.0/24

I could then configure the various options through the web interface. This router has all the functionality that you would expect from a wireless router (eg. NAT / routing / port forwarding), but in my case I disabled all this and set it to work as a Wireless Access Point so that I could use it to replace my previous WAP without needing to change my home network setup.

One thing that was a little frustrating is that the router needed to reboot, or at least spend time doing a soft reset when each change was made. This even included just changing the administrator password. This meant a lot of time during the install waiting for the router to reboot. Once the router is configured then you don’t normally have to make many changes, but this does mean taking down the internal network for some minor changes.

I’ve not overly stressed the new router so far, but at least it seams to cope much better with the interference. The wireless network connection does still slow down at times, but the performance is much better than previous and it is now possible to continue working which was not possible before.

Summary

A cheap and easy to use router capable of high speed networking if required. Easy to setup and works well with Linux.
Only complaint is the fairly minor issue that it needs to reboot the router when making changes to the setup.

Read more »

Lock computer when leaving it unattended

An essential part of computer security is to always lock your computer whenever you leave it. It only takes a couple of minutes with your back turned for someone to access your personal information or change your Facebook status (frape).

Logging out can be a bit of a pain, so luckily there is a quick keyboard shortcut that allows you to lock your computer without logging out. Use the following key combinations to quickly lock you screen.

On Linux

Ctrl-Alt-L

On Windows:

Meta-L

The Meta Key is sometimes called the Windows key. It is a key which often has the Windows logo on and is normally between the Ctrl and Alt keys at the left hand side of the keyboard.

Some keyboards may use different symbols, particularly if they are available with other operating systems. On my EeePC the meta key has a picture of a house on it rather than the Windows logo (home key).

Read more »

Ubuntu Linux – slow wireless network speed – force adapter speed

In the past I have had very poor networking performance on my wireless network (Wireless LAN / WiFi) which appeared to have been caused by interference from other networks. I’ve since upgraded to a Belkin N Wireless Cable router which has certainly improved performance, but I notice that I’m still get some quite slow WiFi speeds on my home network.

Wireless Network Standards

First here’s a bit about the different standards for Wireless Networks.

Or if you want you can skip direct to the solution of how I doubled my network speed with a simple command.

11Mbps to 54Mbps – IEEE 802.11 a/b

The first standards in common use were defined in 1999 when the IEEE created the 802.11a and the 802.11b standards. These were both for wireless networking with the two working at different frequencies and the 802.11a at 5Ghz with a maximum speed of 54Mbps and 802.11b working at 2.4GHz.

As 802.11a worked at a higher frequency it was harder to manufacturer (and hence more expensive and less reliable) and it was also initially not available in Europe due to regulatory issues. Therefore the 802.11b became popular.

There newer standards (listed below) are backwards compatible with 802.11b.

54Mbps IEEE 802.11 g

The next significant standard was the IEEE 802.11g in 2003, but many products were available prior to ratification, which were usually called g-pre or g draft. 802.11g works at the same frequency as 802.11b but increased the speed to 54Mbps.

This was hugely popular and most wireless equipment these days supports at least 802.11g. Much of the equipment being sold is still designed for 802.11g and are often available cheaper than the 802.11n products.

100Mbps+ IEEE 802.11n

The latest version is IEEE 802.11n which works at either 2.4GHz and 5GHz as a replacement for the previous network standards. It provides speeds of up to 100Mbps and even faster with the draft standards.

The speeds provided above are all theoretical maximum speeds. There are many factors that will affect the actual throughput, this includes other wireless users, wireless CCTV cameras, wireless keyboards and mice and even microwave ovens. The speed also changed depending upon the power saving status if using a laptop. Typical speeds may be half of the theoretical maximums or less.

Real Wi-fi network speeds

The majority of network traffic does not need the high speeds quoted. Most of my network access is to the Internet which is limited by my 10Mbps broadband, which in reality runs at nearer 5Mbps download (much slower upload). The high speed can be useful if streaming data over the internal LAN and in my case for transferring backups, but the speed is much better than before.

I have two portable computers that I use at home. I have a Dell Inspiron laptop with 802.11g/n built-in and a Asus EeePC netbook with 802.11n. Both of these are capable of running at 802.11n network speeds, but in reality I have only been able to get these to work at the equivalent of 802.11g speeds.

EeePC

My Eee PC works better with the wireless network at home compared. It worked well with the 802.11g wireless access point and performs the same on the 802.11n router. On Unbutu Linux the wireless driver loaded is the rt800pci and the interface known as wlan0. It appears to show that it is running between 1Mb/s and 54Mb/s, but in tests gave an actual throughput of around 20 to 23Mbps.

Dell Inspiron Laptop

The following is based on Ubuntu Linux.

It is my Dell laptop that had the performance issues that I now solved. The driver loaded is called wl providing interface eth1. Initially it was giving speeds shown as between 1M and 8M, but is now showing as connected at 54Mbps and running at up to 14Mb. This is still much slower than the network is theoretically capable of and less than the speed of the Eee PC, but is adequate for what I need.

Testing the speed of the Wireless network

Before attempting to fix the problem the first step is to check the current performance of the network to quantify the improvements.

Wireless connection information – speed setting

The first place to look for the wireless network speed is in the network manager. Right click on the wireless icon in the top right of the screen and choose “Connection Information”.

The above screenshot shows the speed as 54Mb/s which is typical of an 802.11g network. A low reading (eg. 1Mb/s, 8Mb/s or 12Mb/s) in this speed field does not necessarily mean that it is running so slow as the speed will vary depending upon actual activity and relevant power saving settings. Instead monitor the applet for a period of time whilst performing something that places a large demand on the network (eg. watching a YouTube video).
If working normally then you should see the speed increase.

Testing speed of the local network (Netpipe-tcp)

The value from network manager gives an approximate guide, but to check the actual throughput involves transferring some data over the network and monitoring that. This is exactly what netpipe-tcp does.
To use NetPipe-tcp needs another Linux computer over the network. Fortunately I have a Linux server as my firewall & router using the Wireless router as a Wireless Access Point (WAP) instead of a router.
To use Netpipe-tcp it first needs to be installed on both computers.
This can be done using:
sudo apt-get install netpipe-tcp
On the server run the command
NPtcp
On client run
NPtcp -h <serverip>
It will take a while to run. It’s the later values that show your true network speed as they put a significant load on the network and will have increased the speed if power saving mode is enabled.

Solution to network speed issue

If the speed is less than you expect and the network manager is showing a speed of less than 54Mbps then you can try forcing it to use 54Mbps using iwconfig.
There is no point though if it is already showing 54Mbps in Network Manager (even if it keeps dropping down when inactive) as that is the normal operation already.
First establish the name of the interface. This can be taken from the Connection Information panel in Network Manager. It’s in brackets on next to the interface information.
Or you can find out by running iwconfig with no options.
This is eth1 on my Dell laptop, but wlan0 is a common interface name which is what it is on my EeePC net book. I’ve used eth1 in the example below.
Change the setting dynamically using the following command:
sudo iwconfig eth1 rate 54M
If you have 802.11n you could also use 100M, but on my system this made it slower. Also 54Mbps is a good value to use as this will work with 54g networks if you travel to another area (I’m not sure what the effect is of trying to force 100M on a 54M network).
After making the changes try using NetPipe again and see if the speed has increased.

Making the network speed changes permanent

When running the iwconfig command it will be forgotten when the system next restarts.
To make the changes permanent a file should be created in the /etc/network/if-up.d directory.
On some systems (eg. Fedora / Redhat) then there is instead a single file per interface:
eg. /etc/sysconfig/network-scripts/ifcfg-eth1
In Ubuntu create a new file in /etc/network/if-up.d
you can give it any name, but try and make it meaningful (eg. wireless-speed)
Contents should be as follows:

#!/bin/sh -e
#
# Sets speed of interface to 54M

if [ "$IFACE" = "eth1" ] ; then
        iwconfig eth1 rate 54M
fi

obviously changing the entries form eth1 as appropriate. The command should be made executable:
sudo chmod 755 wireless-speed
The scripts in the /etc/network/if-up.d directory are all run whenever a network interface is brought up. The script checks to see if it is the interface in question and if so runs the iwconfig command that we ran earlier.

Summary

Actual results may vary, but on my system this provided almost a doubling of network throughput speed.

Read more »