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High speed M&M sorting machine

Monday, December 22nd, 2014

M&M sorting machines are a popular project for people who like combining electronics, programming and machine building. I decided I’d try to make my own version but with a different approach to the majority of existing M&M (or Skittles / Smarties!) sorting machines out there.

Most of them send a single M&M down a chute to a simple colour sensor where the colour sensor will then take a second or two to figure out the colour. A servo motor will then rotate a chute that will direct the M&M into the correct pot.

My approach sends M&Ms down a chute to start with. But I don’t stop the M&M for colour recognition. Instead I use an iPhone to capture the colour of the M&M as it is in freefall. As it is still falling the iPhone talks to a Bluetooth module attached to an Arduino and that fires off the correct electro magnet controlled gate. This sends the M&M into the correct pot. Even though this is just a rough prototype it is reasonably fast because the colour recognition and path that the M&M takes down the chute is decided and determined whilst the M&M is moving under gravity. Here’s a video of the prototype:

mandm sorting machine front 12

Initial M&M sorting ideas

I’d been thinking about making an M&M sorter for a while as a fun project so I could play around with an Arduino. But I didn’t want to stop the M&M for colour recognition or use a servo motor to direct the M&M as these approaches seemed slow to me.

It was this video of a high speed coin counting machine that got me thinking about some kind of binary gate that would deflect the M&Ms into the correct place. https://www.youtube.com/watch?v=2GGKYHf8DQo. What they’ve done is really cool and impressive – the coins zoom through a sensor faster than you can see, and are nudged down the correct path by a pop up nodule.

M&M dispenser

Starting from the top of the machine I had to figure out how to ‘release’ the M&Ms one by one.

I did attempt to make some kind of spinning ‘thing’ that would shoot M&Ms down a tube in the style of the coin sorter video I saw. It did kind of shoot them down the tube, but mostly it sent the M&Ms flying all around my living room. I still don’t know if I’ve found them all!

The problem here was making the M&Ms come out one at a time (they often came out in bunches), and the fact that they flew out at different angles and velocities – this would lead to them bouncing around which would make it hard to predict where they were going to go next.

mandm sorting machine dispense experiment 17

I also experimented with a cylinder that the M&Ms would go into first, and then they’d fall though the holes when the holes lined up. I realised here that the amount of torque I’d need to rotate these two tubes would be too much for my motors. Plus there was still the problem of the M&Ms falling out in twos.

mandm sorting machine dispenser experiment 18

I had more success with trying to replicate this tried and tested design adopted by a number of other successful M&M sorters. The M&Ms are in the container and they drop into the holes as the holes become empty.

mandm sorting machine dispenser experiments

The trick to success is to ensure that the height of the hole that the M&M drops into is about the same height as the M&M. This ensures that only one M&M is in the hole at a time. And then as the M&M rotates and approaches the chute it goes under a covered area (like a bridge which touches the surface of the spinning disk) which ensures that when the M&M and the hole line up only the M&M in the hole can fall down.

mandm sorting machine dispenser 10

The bridge is barely visible in the photo as it is obscured by the sides – it is right at the front and is secured into place with that screw. The piece of foam board on the left perhaps helps to encourage the M&Ms into the hole but may not be necessary. I have the dispenser angled to the back so that the M&Ms fall to the edges (I want to ensure that they all go through the sorter).

Spinning the dispensor

I initially bought a 6V 500RPM motor from Amazon, and a set of motor mounts to attach the motor to the spinning disk.

I tried to decrease the speed to something sensible using a set of gears that I got from Maplin. However with my crude setup there was so much juddering that it prevented the M&Ms from falling smoothly.

mandm sorting machine motor gears 3

So I bought a 12V 80RPM high torque motor from eBay along with a motor speed controller which allowed me to direct drive the spinning disk. It was much smoother now, and this shows that simpler is often better.

mandm sorting machine motor 14

Electro magnet gates

I’d decide to try deflecting the M&Ms down the correct chute by using electro magnets to control quick reacting gates. Electro magnets can react very fast – much faster than the slow turning of a servo.

I first bough a very small low powered electro magnet – it was useless as it was so tiny it wouldn’t have been able to move anything. So I bought a bigger 12V 2A pull magnet from eBaay. This had pulling power (and goes back to its original position when the power is off because of the spring).

My first attempt was a simple ‘pull’ gate. Here the pulling of the magnet would close the gate.

mandm sorting machine slide gate 7

I tried doing this with both the magnet on the same level as the chute (above) and also below the chute (below).

mandm sorting machine chute experiments

The problem was that the magnet only pulls 1cm, and taking the diagonal into account that does not fully close the chute. It worked a lot of the time, but sometimes an M&M would slip past the gate. As I couldn’t find electro magnets with a larger pull length (one with 2-3cm would have made all this much simpler!) I went for a ‘chop’ gate instead.

As the electro magnet pulls back the gate ‘chops’ downwards by means of 3 pivot points. This design turns the small amount of electro magnet movement into something much larger which can cover the entire width of the chute diagonally.

The difficulty is figuring out the exact shape and size of the moving parts. I didn’t have any scientific way of doing this – I just experimented. First using thin cereal box cardboard as shown in the image on the right. Then using rigid plastic sheet that I bought from a hobby shop. On the left is the final design I went for. These gates react extremely fast, and make quite a bang as the plastic hits the bottom of the chute.

mandm sorting machine electro magnet gates experiment

I had to make 5 of them and here is what they were looking like when glued (using a glue gun) onto the foam board. I added a bit of black tape (which was loose at the bottom) to slightly muffle the sound.

mandm sorting machine side electro magnet gates

Colour sorting of M&Ms

I knew that I was going to use an Arduino to control the M&M sorter so it seemed natural to buy the Arduino compatible colour sensor that most of the other projects were using. The colour sensor is in the photo on the left and is the thing that the bright white light is coming from. What I discovered though using it was that the sensor is very slow. You have to individually sample the 4 colour sensors (red, green, blue and white) and then figure out the colour. This isn’t as easy as the sensors aren’t calibrated with each other, so you need to figure out the calibration first.

mandm sorting machine side arduino bluetooth

I abandoned the colour sensor as too slow (I can see why the designs that use this sensor have to stop the M&M to figure out the colour now) and decided to use an iPhone 5S camera instead. The iPhone’s camera and CPU was fast enough to film the M&M in free fall and 1) spot that there was an M&M in the field of view and 2) figure out what colour it was. The traditional cheap colour sensors available for the Arduino wouldn’t have even been able to detect that an M&M was even there as it wizzed past in freefall.

The camera is placed a bit back from the chute to give it a wider field of view. And for efficiency it is only processing the vertical strip of pixels that make up the chute. No need to process the parts of the image that the M&M will never appear in.

I bought a Bluetooth LE module for the Arduino (shown in red above) so that the iPhone could talk to the Arduino.

To make determining the colour more simple I flattened the colour palette of the video images as they came in. I made it so the software only saw the colours of the M&Ms that I was interested in seeing (so no shadows which were a big problem!) and everything else was white. It was then simply a matter of counting the number of coloured pixels, and then if the number was above a threshold sending the Bluetooth command to the Arduino.

mandm sorting machine iphone 5

Here you can see the Bluetooth board plugged into the Arduino and wired up to the relay. Wires are then heading out of the relay to the electro magnets.

mandm sorting machine back arduino 13

Putting the M&M machine together

Once the three key problems of the 1) M&M dispenser, 2) electro magnet gates and the 3) colour recognition were solved it is just a matter of putting it all together. This involved a lot of foam board and glue from a hot glue gun.

I used a sharp hobby knife to cut the foam board, and bought a cutting compass so that I could cut neat circles for the dispenser.

As I started testing various bits together I did find a few problems.

  • The M&Ms would ricochet about as they fell down the chute, sometimes ricocheting down the wrong chute before they had reached their gate. I kind-of solved this by putting the chute at an angle so the M&Ms would be ‘encouraged’ to stay on the smooth side of the chute.
  • The electro magnets could get very hot if left on. So hot in fact they could melt the glue that was holding them in place. I had to modify the software to disengage the magnets after they’d been fired (but after the M&M had hit) rather than leaving them in the engaged position.

Here’s a side view of the assembled prototype.

mandm sorting machine side 15

And here is the front view. It differs slightly from the version in the video as I extended the M&M ‘pots’ at the bottom to store more M&Ms and I added a button to turn the motor on/off at the top as well as a speed dial for the motor.

mandm sorting machine front 12

I have a small compilation of video snippets of earlier M&M sorting experiments on YouTube.

Future improvement ideas

I think there is a lot of potential for improving on this design. I think with some improvements the speed and accuracy of the M&M sorting could be better.

  • Try to get rid of the whole iPhone / Bluetooth setup. I think to do this you could try using a Raspberry Pi with a high speed (60/120FPS) capable camera directly attached. The Pi probably has the processing power to do the image processing.
  • At the moment there are three power supplies – one for the Arduino, one for the electro magnets, and one for the motor. It would be great to get everything running off a single power supply.
  • More work on the image processing – you may have noticed I wasn’t sorting brown M&Ms. They are a pain to distinguish from orange and shadow. Obviously it can be done but it would need a bit more software work and perhaps some LED lighting on the chute to reduce the effect of the shadows.
  • 3D printing of the parts – my prototype is very rough – it would be amazing to see it as a smooth 3D printed consumer unit.

Currently the gates are in a line – this causes slight timing issues – there is less time between the camera recognising the M&M colour and the first gate needing to fire than the last gate needing to fire. NES4_Life came up with the suggestion of having all the chutes arranged in circle (like a flower) and then have the chutes move into the centre at the correct time. This would mean a fairly constant time between colour recognition and firing the electro magnet which could simplify things, especially if the speeds get higher. I did a quick test of the concept (below) and I think it has potential but I haven’t figured out exactly how to do it.

mandm sorting machine flower gate experiment 24

Some of the items I bought for the M&M machine

Here a partial list of what I bought – I’ll try to add more if I remember!

Bought and used on final prototype

  • Arduino Mega kit – comes with lots of extra components to play with.
  • Extra jumper cables
  • 8 channel relay module
  • Arduino Bluetooth Low Energy (BLE)Shield – £18.05
  • Various power supplies (which I won’t give links to as the ones I got were really dodgy ones that I’m sure weren’t properly safety tested!)
  • DC 12V 2A Push Pull Type Open Frame Solenoid Electromagnet 10mm 20N 4.4LB * 5 – ~£5 each, the ones I bough are listed on eBay not but there from the same seller but are loads of other identical ones on the site
  • 12V 80RPM motor from eBay – £6.30
  • Motor mounts – for attaching the motor to the spinning dispenser disk.
  • PWM Pulse Width DC Motor Speed Control Controller Governor 6V-28V 3A – £5.59 from eBay
  • 30cm steel ruler
  • Circle cutting compass – from any good hobby shop
  • Foamboard – lots of this!
  • Plastic sheet – white for the electro magnet gates
  • Plastic sheet – clear to cover the M&M chutes and stop the M&Ms bouncing out on their way down to their designated pot.

Bought but not used on the final prototype

Other M&M / Skittles sorting projects

Here’s a list of other M&M sorting projects that I’m aware of (in alphabetical order). It is definitely worth looking at all of them to get inspiration for your own.

Lego Mindstorms M&M Sorting Machine
Lego Mindstorms NXT – The M&M Dispencer
m&m’s sorter
m&m sorter #3, take two
M&M sorter
M&M Sorter (da Vinci’s Workshop)
Skittles Sorting Machine 3
Sorting Machine – Skittles and M&M’s

And there’s even more if you search on YouTube!

Who are North Korea’s 13 Twitter friends?

Thursday, October 7th, 2010

In the past few months North Korea has embraced social media, first creating a YouTube channel, and in August a Twitter account with the name @uriminzok, which roughly means ‘our people’ in Korean.

uriminzok following wide

uriminzok followingNorth Korea has since been busy and has already racked up 457 tweets for its 10,334 followers. Pyongyang is however being very selective over who it chooses to follow. As of today it has followed only 13 other accounts. Who are these 13 accounts that North Korea has deemed worthy of following? You might be surprised by the answer.


1. @noaheverett

noaheverettNoah Everett is the creator of TwitPic, the service that makes photo sharing on Twitter easy.

North Korea has become a regular user of TwitPic to share photos from around North Korea, as well as political cartoons. To date they have shared 30 photos using the service.

Perhaps that is why they have befriended the TwitPic creator.


2. @TwitPic

twitpicAs if to confirm their love of TwitPic, North Korea are also following the official TwitPic account. Presumably to keep up to date with the lastest TwitPic features, and API updates.

Sidenote: North Korea are also heavy users of TinyUrl on their Twitter account but haven’t become friends with them yet.


3. @ljwalters

ljwaltersDespite only having 4 Tweets with a combined total of 12 words, ljwalters has managed to get 50 followers including the North Korean account.

ljwalters 12 tweeted words reveal a Happy Birthday message to ‘Peter’ and the fact that he/she is reading ‘Outliers’. Still this was enough to grab the attention of the Democratic People’s Republic of Korea, and mark ljwalters as one of the chosen 13.


4. @RadioactiveHair

radioactivehairRadioactiveHair is a Twitter user who follows 93, and has 16 followers. This user’s 168 tweets reveal a possible like of ‘Rap’ music. In September this user sent a message to North Korea’s @uriminzok account expressing admiration for Kim Jong Il. They are now Twitter friends.


5. @comandantmarcus

comandantmarcuscomandantmarcus runs a socialist website on tumblr where he lists ideas for housing, transport, music, alcohol and more. Perhaps the DPRK were inspired by his thoughts, which prompted them to follow him.


6. @_chinpingpong

 chinpingpongIt is harder to understand why North Korea is following _chinpingpong. This user is a very regular tweeter with 9,414 tweets and 191 followers.

Recent tweet topics include Inception, music, and The Big Bang Theory (the TV show). This account doesn’t look like an obvious one for Kim Jong Il and the DPRK to follow. But that changed after _chinpingpong retweeted one of @uriminzok messages. North Korea then decided to follow this user.


7. @JimmyDushku

jimmydushkuJimmyDushku is another committed tweeter with 2,649 tweets to his name. He is tweeting about life and the news. One of his tweets caught my eye: “Only way things would go better would be if I got my N. Korean visa”.

Perhaps this is the reason for North Korea’s interest in Jimmy. Maybe they want to ensure that his visa is successfully obtained, and that he has a good time when he visits.


8. @DaveP18

davep18DaveP18 only has 13 tweets, but two of them reference uriminzok. Other tweets reference Tiger Woods, the App Store, and Vladimir Putin. Seems that was good enough for Pyongyang.


9. @________T__

        t  ________T__ (if that is his real name) only has two tweets in his account. The first is a retweet of a tweet from uriminzok. The second is thanking uriminzok for following him. “It is an honour” he says.


10. @eduardo_89

eduardo 89eduardo_89 is a student from Mexico living in Berlin who is interested in politics, economics, history, architecture, and photography (it says this on his website).

The link between him and North Korea seems to have started on September 14th when he sent a tweet to uriminzok asking how to get a visa to visit. uriminzok tweeted back the advice that this can be arranged at the embassy or consulate mission to the DPRK and that “Pyongyang always welcome you”.

They have been mutual followers ever since.

Sidenote: If you want to visit North Korea there is nothing stopping you. The government run tours of selected sites, and as long as you are happy to be followed by their guides 24/7 and do what they say, you should have no problems. Wikipedia has an article about tourism in North Korea here.


11. @khomeninja

khomeninjakhomeninja tweets about Obama, Palin, and politics. Maybe Pyongyang appreciates the political opinions offered by this user’s 173 tweets.


12. @olakrez

olakrezolakrez has produced 23 tweets so far and is mostly tweeting about what he/she is doing. Nothing North Korea related until a welcome message to uriminzok was posted on September 2nd.

uriminzok returned the favour by following olakrez.


13. @qwertyvn

qwertyvnqwertyvn lists their location as Vietnam, and sends uriminzok a message announcing that their countries are friends on September 3rd. And according to Twitter they are! qwertyvn has only had time to post three messages but two of them reference North Korea’s official Twitter account.


Conclusions

Can we learn anything about North Korea’s secretive regime from who it is following? I don’t think so. I’d guess that when they set up their Twitter account, they just followed the first bunch of people who tweeted messages to them or about them. Maybe at some point they’ll clean up the list and follow a different group of people who better reflect the political opinions of the DPRK.

If you want to be updated by Twitter when new posts appear on reviewmylife you can follow me at @reviewmylifeuk.

i-gotU GT-600 GPS data logger review

Thursday, September 9th, 2010

The last time I reviewed a stand alone GPS data logger it was the GlobalSat DG-100, a functional but not very stylish box for recording GPS tracks.

The new i-gotU GT-600 GPS Travel & Sports Logger from Mobile Action (disclosure: they sent it to me for free) has the same SiRF Star III chipset as the DG-100, but it comes in a smaller and more attractive package.

i gotu gt 600 gps data logger 01

You’ll want a GPS data logger if you want to record your travel and sports tracks (walking, running, cycling, sailing, etc) and tag your photos with their GPS locations. Recording this GPS information will allow you to examine your route on the computer later on, and see exactly where you were when you took your photos.

i-gotU GT-600 hardware

The GPS measures just 46×41.5x14mm and weighs only 37g. It is made of shiny white plastic, and there is a soft plastic case around it (presumably to protect it if you drop it). Here is what the packaging looks like from the front and back.

i gotu gt 600 gps data logger 02

And this is what is inside the packaging. You get the GPS data logger, a USB cable, a velcro strap, and a mini install CD. If you have Windows 7 you won’t need the CD – you will have to download the software from their website.

i gotu gt 600 gps data logger 03

Here is a closer look at the sides of the unit. On one side is the cable connection, and on another there is a hole which you could use to attach a wrist strap.

i gotu gt 600 gps data logger 04

Here is the underside of the unit, the holes in the casing are there for you to feed the velcro strap through.

i gotu gt 600 gps data logger 05

The velcro strap allows you to attach the GPS unit to your rucksack, bike, boat, etc. Ideally you should have the unit positioned so that the front faces clear sky. Here is the unit strapped to my bike, ready for a cycle around the city.

i gotu gt 600 gps data logger 06

i-gotU GT-600 in use

There is only one button on the GT-600. Just hold it for a few seconds and a blue LED (under the plastic) will light up. You then need to wait for 30-60 seconds for it to get a lock on the satellites.

How long it takes depends on how many satellites are above visible from your current location, and also on cloud cover. In ideal circumstances it could get a lock in about 30 seconds. The time will also be reduced if it was on in the last few hours as it will still know the positions of some of the satellites. Once it has a lock then both the red and blue lights will start flashing.

Once it starts recording you can do whatever you want; Walk, run, cycle, sail, and it will log your position every 5 seconds. The unit is water resistant so it should be ok to use in the rain.

Remember to check the unit’s flashing lights regularly to make it is still recording. It can be very annoying if you get home and realise that only half your journey was recorded because a thick cloud or other GPS signal blocker stopped the unit from logging your GPS tracks.

The battery lasts about 30 hours if you log every 5 seconds (longer if you increase the logging interval) and is charged by the same USB cable that you use to transfer the GPS data.

The unit can store 262,000 way points (locations) so if it is logging every 5 seconds this will be enough for 363 hours GPS tracks. More than enough for most adventures!

To make the battery and memory go further it has a motion detector built in. If you are still for a while (perhaps you have stopped for lunch for example) it will stop recording. They claim that this will give you an extra 20% logging time.

Holding the button for a few seconds will turn the unit off. Because the button is easy to press I’d recommend that you don’t keep the unit in your back pocket. If you do you may well accidently turn it off when you sit down, or bend over. Either keep it strapped to your rucksack, bike, or clothing using the strap, or be careful to place it so that the button won’t be pressed. I find it works fine when put in the front pocket of my rucksack. The logging might now be quite as accurate as it would be if it had a view of the clear sky, but it is good enough.

To sync your data to your PC you just plug it in via the USB cable and start up the @trip PC software.

i gotu gt 600 gps data logger 07

i-gotU software

The i-gotU GT-600 GPS data logger comes with three pieces of software.

  • @trip PC – which is the software you’ll want to use if you want to manage your trips and geotag your photos.
  • Sports Analyzer – which shows your GPS tracks in a view that allows you to easily see average speed, calories burned, and when you did each of your activities.
  • Where I am – which simply shows you where you are now on a map.

I’ve mainly been using @trip PC. After importing the GPS tracks you have the option to create a ‘trip’. A trip can consist of one or more GPS tracks along with the associated photos. If you have synced multiple tracks you can go back and create new trips for the other tracks later on without having to sync again.

i gotu gt 600 gps data logger 09

You can choose which photos you want to include in the trip. When you’ve chosen them the software can add GPS location information into the image.

i gotu gt 600 gps data logger 10

After creating the trip you’ll get something a bit like this. It shows you the route you took, and the locations of all your photos. You can ‘play’ the trip and watch a moving icon go along your route. The photos you took will pop up as the icon reaches them.

i gotu gt 600 gps data logger 12

i gotu gt 600 gps data logger 13

You can customise the look of your trip. The view above is the basic view, and the one below is a sporty view which shows a graph of your speed and a few sporty facts about your trip such as total distance, and average speed.

i gotu gt 600 gps data logger 14

The @trip PC software is easy and quick to use for viewing your tracks and tagging your photos. The main thing it lacks is an sensible way to delete rogue way points (sometime you’ll want to manually clean up your tracks a bit). You can get a list of all way points, but when you have thousands of them it can take several minutes to find the one you want. The software should ideally let you select one or more way points by clicking on them to allow speedy moving or deletion.

In the version of the software I used (2010.06.09) there were some UI annoyances, and other problem such as slow syncing, and unreliable communication with the hardware – on my Windows 7 machine if you have done a sync, you can’t delete the data on the device unless you unplug and replug the device back in – you get a ‘Failed to clear log data. (Error=4)’. But you can work around all these issues.

If you are only interested in sports tracking and aren’t going to geotag any photos you can use the Sports Analyzer software instead. This is a simpler interface which just shows you your tracks along with speed, distance, calories burned etc.

sports analyzer

i-gotU GT-600 advanced configuration

Using the @trip PC software there are some advanced options you can configure. You can set the GPS unit to only record at certain times of the day. And you can set how frequently the unit logs your position.

i gotu gt 600 advanced options

Sharing your trip

If you don’t just want to keep your trip to yourself you can share it with just a few clicks. The @trip PC software can upload your tracks and photos to the @trip server. You have the option of uploading the photos to the @trip server (it will shrink the photos for you), flickr, or Picasa.

Your free @trip account only give you 100mb of space on the @trip server so I’d recommend creating a free Picasa account to your save your @trip account space for the GPS tracks. A Picasa account will give you 1024mb of photo space. Or if you already have a paid flickr account then that will be best as you can store unlimited photos there.

Here is the @trip interface showing some trips that I uploaded (one public, one private).

i gotu gt 600 gps data logger 17

Once uploaded to the @trip server you can view the trip in a flat Google Maps view, or by using a 3D Google Earth view – this will be great if you are recording your mountaineering, or hand gliding adventure.

i gotu gt 600 gps data logger 19

Rather than just looking at a static image of my @trip account your can have a look at the real thing showing a trip I made to Naoshima Island in Japan.

There is an option on the @trip server that allows you to embed a trip in your blog, such as I have done below.

Overall verdict of the i-gotU GT-600

This is a good GPS data logger with a long battery life, and large memory. The unit is small, easy to use, and has worked reliably during my two weeks of testing. The software makes it very simple to view your trips on your PC, geotag your photos, and share them all on the internet. I’m just hoping they release a software update to sort out the minor problems and bugs that I found.

Where to buy

If you are in the UK the GT-600 is available from this seller on Amazon, but last time I checked it was slightly cheaper from Maplin.

For more comprehensive information on where to buy the GT-600 around the world see Mobile Action’s – Where To Buy page.

Update: 15th September 2010 – @trip PC suite not loading issue

I started having a problem where @trip PC suite would not load (at all). But Sports Analyzer still loaded. I tracked it down to a corrupt sub folder in this resource directory – C:\Users\[username]\AppData\Roaming\Mobile Action\atrip\Resource. If you are having this same problem and want to try to track down which folder is corrupt.

  1. Backup the whole resource folder (C:\Users\[username]\AppData\Roaming\Mobile Action\atrip\Resource) so you can restore it later.
  2. Rename one of the sub folders in this directory and try restarting @trip PC. The corrupt one will probably be one of the ones you’ve edited most recently.
  3. Repeat until you find the corrupt one. You have found the corrupt one when @trip PC starts. However you’ll now see that in @trip PC all the trips belonging to the resource directories that you renamed have disappeared.
  4. Exit @trip PC.
  5. Now restore the whole resource folder from your backup, and then delete the corrupt sub folder.
  6. Restart @trip PC and you should have all your trips back (minus the corrupt one). You’ll have to recreate the corrupt trip if you want it back.

An extra bit of info if you are digging deeper: A list of the sub folders is stored in C:\Users\[username]\AppData\Roaming\Mobile Action\atrip\Resource\RESOURCE_INFO.INI. When you successfully manage to load @trip PC again it will delete the entries for the folders that you renamed. You need to restore from your backup (point 5 above) so @trip PC knows about the non-corrupt sub folders that you renamed.

2010-2011 UK Tax graphs

Tuesday, June 15th, 2010

Straight after putting up the tax graphs for 2009-2010, I’m putting up the tax graphs for this tax year. This time the graphs are better, and some of them include a comparison line with the previous year’s figures.

As before I’ll state I’m not an accountant or tax expert so I can’t guarantee their accuracy, but I’ve done my best. The graphs assume that you are getting the default allowances. Let’s start with an overview of how much tax you’ll pay.

2010 2011 total tax graph

The big change for this year is the new higher 50% rate of tax, and the tapering off of your personal allowance once you reach the income limit. For most people this has no impact, it is only once you start getting over £100,000 that your tax will rise. You can clearly see the change in tax by comparing the red and blue lines in the graph.

Next is a more visual way of seeing the tax changes. The first slope is where the personal allowance tapers off, and the next one is where the 50% tax band kicks in.

2010 2011 tax changes

Income tax and national insurance

The overall tax you’ll pay is composed of income tax and national insurance. Here are two graphs showing how much of each one you’ll be paying.

2010 2011 income tax graph

2010 2011 national insurance graph

Gross salary vs net salary

Here is a graph showing your gross salary vs your net salary.

2010 2011 gross salary vs net salary graph

And a more zoomed in version which only goes up to £60,000.

2010 2011 gross salary vs net salary graph zoomed

Percentage of tax

And finally I have a graph showing the percentage of tax you pay against your gross salary. You can see that the new tax changes have made the shape more uneven (i.e. more complicated) than in the previous tax year. This is sure to be good news for accountants!

2010 2011 tax vs gross salary

Windows 7 on a 2010 MacBook Pro 13 inch

Tuesday, June 8th, 2010

I’m going to review what it is like to use Windows 7 Home Premium on a 2010 MacBook Pro 13 inch. This is one of the 2.4GHz models with 4GB of RAM.

macbook pro running windows 7 aero

Some parts of this review would be applicable for running Windows 7 on any Mac, but other parts may be specific to the 2010 MacBook Pro 13 inch.

Installing and setting up Windows 7

I installed the 32 bit edition of Windows 7 rather than the 64 bit version on the assumption that more 3rd party software and drivers would be compatible with the 32 bit version.

windows 7 home premium

Installing and setting up Windows 7 using Boot Camp is simple and takes less than an hour (most of that time is take by Windows 7 installing and setting itself up).

On a previous post I’ve put links to the Boot Camp install instructions. And if you want a writable shared partition I’ve written up my own instructions for how to add a third shared writable partition to your MacBook hard drive.

Booting up Windows 7

By default the MacBook will boot into Mac OS X. If you hold down the ‘alt’ key when you turn it on you will get boot selection screen in about 10 seconds that will allow you to choose to boot from either the Mac OS X partition or the Windows 7 partition.

boot camp os selection screen

On choosing Windows 7 it then takes my month old install of Windows 7 48 seconds to reach the login screen. And once I’ve submitted my user details it takes another 15 seconds for the desktop to be fully loaded (with all the taskbar icons in place and for the mouse cursor to be idle).

Using the MacBook Pro track pad for Windows 7

The MacBook has a large multi-touch track pad and Apple have allowed some of the multi-touch functionality to be used in Windows.

macbook pro trackpad

Moving across the trackpad with a single finger moves the mouse cursor as you’d expect.

Moving up and down with two fingers will scroll the current page up and down.

As there are no left/right buttons on the trackpad you have to click with a single finger for left-click, and click using two fingers for right-click. You can also configure the track pad to accept a single click in either the bottom left, or bottom right of the screen for the right click.

No three or four fingered gestures are supported yet.

Using the MacBook Pro keyboard for Windows 7

The keyboard is large and feels good to type with, but it is with the keyboard that you may run into problems when you start using Windows 7. Many of the standard Windows keys that you are used to aren’t on the keyboard. For example there is no Home, End, Page Up, Page Down, Print Screen, Del, or Windows key.

Here are the keyboard shortcuts that allow you to get the functionality of these keys on your MacBook Pro.

  • Home – fn + left arrow
  • End – fn + right arrow
  • Page Up – fn + up arrow
  • Page Down – fn + down arrow
  • Print Screen – fn + shift + F11 (and for just the current window fn+shift+alt+F11)
  • Del – fn + backspace
  • Windows key – cmd
  • Pause/Break – fn + esc (you can therefore bring up the system properties with cmd+fn+esc – normally Win+Pause with Windows keyboard)
  • Hash symbol (#) – ctrl + alt + 3
  • Ctrl-alt-del – ctrl + alt + fn + backspace

Apple have a larger list of keyboard mappings, but many of them are for other types of Macs and don’t work on the MacBook Pro. Wikipedia has a big list of keyboard shortcuts that you can try as well – but again many of them aren’t applicable to the MacBook Pro keyboard.

USB, display port, and other hardware

Apple have been quite stingy with their USB ports. There are only two. If you want to attach more devices you’ll need to plug in a hub. Also both ports are very close together, so if you plug in a USB device with a larger than specification plug, you might not be able to plug in a second USB device. There is a FireWire 800 port as well if you have any FireWire 800 devices to plug in.

macbook pro usb and display ports

You won’t find any PC standard VGA monitor plug on the MacBook Pro. There is a Mini DisplayPort instead, so if you want to plug in a VGA monitor, or projector you’ll need to pay extra for an adaptor like this one.

The DVD drive, web cam, and SD drive all work as expected on the MacBook Pro.

System properties – Windows Experience Score, usable RAM, and battery life

The Windows Experience Index of Windows 7 (with Aero) on the 13 inch MacBook Pro is 5.3. I put more details on my MacBook Pro Windows Experience score page.

When booted the usable RAM is 2.74 GB. This is because 32 bit versions of Windows can only address about 3.3GB of RAM. The reason it shows less than 3.3GB is because part of the address space is allocated to other parts of the system (mostly to the graphics card I’m guessing). Using the 64 bit version of Windows 7 would allow more of your RAM to be used by Windows, but I can’t tell you what the 64 bit version of Windows 7 is like as I haven’t tried it.

The battery life of the MacBook Pro when running Mac OS X is about 10 hours. When running Windows 7 it is about 4 hours. Still good for a Windows laptop, but it is a shame the battery life isn’t closer to the Mac OS X battery life.

Features such as hibernate and standby both work well. When hibernating you’ll have to make sure you select to boot from Windows on the boot partition selector if Mac OS X is your default OS.

Boot Camp control panel

In the Windows 7 taskbar (or from the Control Panel) you can access the Boot Camp control panel.

boot camp control panel windows 7

It will let you change settings relating to the keyboard mappings, and how the trackpad works. You can set how you activate the right-click for example. Right clicking on the taskbar icon gives you a ‘Restart in Mac OS X’ option.

Default boot partition

After installing Windows 7 via Boot Camp the default boot partition will probably be OS X. If you want to change it to be Windows 7, boot into OS X, go to the System Preferences, then Startup Disk, and choose the Boot Camp partition

Useful MacBook Pro utilities for Windows 7

If I find useful utility programs for Windows 7 on a MacBook Pro I’ll list them here.

  1. TrackpadMagic – if you are playing a game using a mouse and keyboard, you may find that you accidently hit the trackpad. This free utility will allow you to enable or disable the trackpad easily. You can also configure it to automatically disable the trackpad when you plug in a mouse.

Windows 7 on MacBook Pro problems

When I got the MacBook Pro a few weeks after it was released there was a problem where no sound came out of the headphone jack in Windows 7 (the headphone socket worked fine on Mac OS X. Apple have now released a patch for this problem – here is the 32 bit version, and the 64 bit version.

Freezes in Windows 7 on MacBook Pro – Updated

The most serious problems that I have encountered are complete freezes of the Windows 7 OS. I know I’m not the only person having this problem with running on Windows 7 on Mac OS as a simple Google search will show.

In my case I can be using Windows 7 for many hours, and then without warning it will completely freeze. The mouse and keyboard will both stop responding. Sometimes the system will wake up briefly after a few minutes, only to freeze again seconds later. Once it has got into this frozen state I find I need a reboot to fix it.

I’ve looked into some of the proposed solutions, but many of them aren’t applicable to the 2010 MacBook Pro 13 inch. What I’m trying at the moment is running Windows 7 with Aero turned off (using the Windows Classic interface).

Update 7th July 2010: I’ve now been running Windows 7 with the Classic UI instead of Aero for a month. Since switching to the Classic UI I have had none of the regular freezes that I’d been getting before. It looks like the freeze problems are therefore due to Aero / graphics chip related issues. Fingers crossed that either Apple or Microsoft release an update soon that allows Aero to be used without problems on the MacBook Pro. In the mean time I’m sticking with the Classic UI.

Update 30th November 2010: I switched back to Aero 4 days ago and so far no freezes. Looks like the problem is fixed, but I’ll update this post if any more freezes occur.

The good and bad

Good points of running Windows 7 on the 2010 MacBook Pro 13 inch.

  • Windows 7 runs smoothly and fast (when it doesn’t freeze).
  • Great screen for Windows applications or video.
  • Much more attractive than any other Windows laptop.

Bad points with Windows 7 on the 2010 MacBook Pro 13 inch.

  • Expensive!
  • The OS freezes after a few hours of intensive use when using the Aero UI (see the above update for the latest details).
  • Some of the standard Windows keys are missing from the keyboard. You’ll need to learn the shortcuts, or use an external keyboard to access them.
  • No Windows standard display display out (e.g. no VGA).
  • Only two USB ports.

Here is a final photo. This is how I use my MacBook Pro at home. I have an external keyboard, USB hub and wireless mouse. With these extras it doesn’t look as neat, but it is much easier to use.

macbook windows keyboard hub mouse

If you want to know how it is packaged look at my MacBook Pro – What’s in the box? post.

Internet doomsday scenarios

Tuesday, May 25th, 2010

For something we have become so reliant on the internet is worryingly open to attack. From attacks on the physical infrastructure, to the computers connected to it, to the data which is stored in it, I’m going to go through some potential internet doomsday scenarios.

Mass deliberate cutting of internet cables

The number of computers on the internet is large. The number of cables which connect the continents is small. This image of the internet’s undersea cables is a few years old but it is still relevant. It shows how fragile the internet’s infrastructure really is.

lan cables

There have already been numerous incidents where areas such as India and the Middle East, West Africa and Dubai have had their internet access severely disrupted. The cause can be ship’s anchors cutting the cables, earthquakes, or component failure.

Even these small incidents can have big knock on impacts, as the failure of one major cable puts extra pressure on other cables to take the extra data – making them more likely to fail as a knock on consequence. Some countries are almost totally reliant on a single cable.

Accidental cable damage has already caused major internet failures. Imagine if a deliberate attack was carried out on numerous cables at the same time, either by a standard terrorist, or some Bond-esque villain intent on removing our ability to watch videos of skateboarding dogs.

If a large enough number of cables were cut the internet could grind to a complete halt.

Yes the damage is fixable, but when you are dealing with cables that are far under the sea it takes time to repair them.

Much of the world could be left without usable internet for days or even weeks. The problem would be compounded by people’s panic reactions. Whenever a major terrorist attack is carried out, people flock to the internet to try to find out more. This creates additional load on the network which compounds the problem.

Search engine data theft

Chances are you use regularly use a search engine. Think back of all the search terms you typed in. I bet you’ve typed searched for things that you wouldn’t want anyone else to know about.

lan cables connecting to router

It could be the things you have searched for would cause major embarrassment to you if your friends or family found out. Maybe if this data were ever made public maybe you would lose your job. Possibly you would be severely shamed. In the worst case if you searched for illegal content you could be prosecuted and imprisoned if found out.

All search engines store your search queries for various purposes, the most obvious being to target relevant adverts at you. They store the raw data for a certain time, and then carry out some form of anonymisation on the data.

A major search engine for example has reduced the time until they anonymise IP addresses from 18 months to 9 months, but is the anonymisation really sufficient?

It seems not, they only change ‘some’ bits of the IP address after 9 months, and you have to wait 18 months to have the last 8 bits and the cookie information changed. This is hardly anonymisation as the associations between can potentially be reconstructed with using the other information in the logs such as the search terms.

If you have ever done searches where you look for you own name, post or zip code, or other personally identifiable information then you are leaving markers in the logs that would allow the information to be reconstructed and attributed to you, even after their anonymisation process is carried out.

Look at what happened when AOL deliberately released search data that they had ‘anonymised’. Researchers and journalists were soon able to track down some of the people who had been typing in those search terms.

So what is the doomsday scenario?

All that data is sitting there in the search engine’s huge data centres all around the world. All it takes is one person to hack in, or one disgruntled employee to send some of the data out.

The search data that AOL released only took up 439mb compressed. Imagine the damage a disgruntled search engine employee with a 1TB hard drive could cause.

Data theft isn’t some far out scenario. It happens all the time. Look at the OSF data loss database if you want to see how often it is happening.

Other data theft

As you can imagine the damage a major search engine data leak or theft could occur, I’m sure you can imagine the damage that could be caused if a major collector of personal data such as Facebook or Hotmail had their data stolen.

router control panel

What would you do if all your email from the last one, two, five, or ten years was made public, for all to see?

Data destruction

More and more of our data is moving from being stored on local computers to centralised data centres which might be in another country (media companies like to refer to the network of data centres as ‘the cloud’). In theory the companies that store our data should be backing it up so if something goes wrong, no data is lost.

Problems occur because when something goes wrong with the original data, the companies often find that their backups don’t work as expected. How often do you test your backups? People just assume that backups will work, and by the time they realise that something is wrong with the backup it is too late.

One example is the social bookmarking site Ma.gnolia who lost all their user data in 2009. The quantity of data lost was only half a terabyte. An amount that you can fit in a pocket hard drive.

If things can go wrong when you have a mere half a terabyte of data, imagine what can go wrong when companies have petabyes, or even exabytes of data.

A better known data destruction close call was the 2009 Sidekick data loss when 800,000 user’s data was lost from Microsoft data centres. Most of the data was subsequently recovered, it is not clear if anyone permanently lost data, but it was certainly a close call for many.

Many of these data destruction events have been down to software errors, but it can only be a matter of time before a well know company suffers a big data centre fire, or until a data centre is deliberately targeted by terrorists.

DNS hacking

The current IPV4 internet was never designed to be secure. Much of it relies on trust. This worked alright when it was just used by scientists, and academics. But now that the internet is open to all, this trust is leading to problems.

One of the cornerstones of the web is the DNS system. We trust it everyday to tell our computer where to find the web address that we type in, or click on.

A URL such as bbc.co.uk is not an address that allows a computer to directly access the website. There is an additional step where a trusted server, known as a DNS server, has to translate the URL into something the computer can find such as 212.58.224.138. This block of four numbers is an IP address. It is the address of a computer on the internet.

We trust the DNS server to give our computer the correct IP address. Problems happen when it doesn’t.

Imagine that we type in the URL for our bank. And instead of giving us the IP address for our bank it gives us the IP address for the computer of a criminal gang (this is known as a DNS hack). Instead of going to our bank’s website we will go to the criminal’s website.

It is not difficult for them to make their website look just like our bank’s website. The address you see in the browser would even be identical so you might never know that you were at the wrong website. They can even produce a fake certificate so you get the padlock icon in your browser that makes you think the website is safe.

Once they have convinced you that their website is the real bank’s website it is trivial for them to get your bank login details off you. In some cases they can forward requests from their fake bank website to the genuine bank website to get your real account information so that they can present you with the correct account balance, and online statement values.

If this attack is done on a high profile bank or other high profile organisation it will get found out. But how long would it take. Maybe a few hours? Maybe half an hour? Maybe it would even be found out sooner.

Even if the DNS hack was quickly closed down the criminals could still steal a large amount of user account details in a very short time. In this time they could initiate purchases, money transfers, or other data thefts.

They could make off with a serious amount of money before anyone realises what has happened.

This kind of DNS hack can be done. China’s largest search engine Baidu recently had their DNS details changed to point somewhere else.

I’ve mainly spoken about using a DNS back to steal bank account details, but it could be used for other purposes. The fake website could install viruses or spyware, promote some political cause, corrupt your data, or steal other data that you would normally type into the trusted website.

Global webcam or microphone hack

Most new laptops and netbooks have cameras and microphones built in these days. Unless you cover up the camera (with bluetak for example) you will be sitting in front of the computer with a camera watching everything you do, and a microphone listening to what you say.

camera phone lens

What if someone managed to hack into your camera, or the cameras of thousands, hundreds of thousands, or even millions of computers? Webcam hacking is something that has already been done on a small scale. There are even websites out there that claim to identify webcams that can easily be hacked into.

The malicious hacker could take covert photos or video of you. And they could use a virus to access your microphone. Many people leave their laptop on in their living room. If a virus was able to access your laptop microphone it would just be like having a spy’s listening bug in your living room.

The malicious virus spreader could record your most personal conversations in full, and could potentially record photos and video as well.

Most laptops do have a basic safety device to prevent the webcam being used without your knowledge. They have a light which will turn on when the camera is activated. If you noticed the light (and I bet a lot of people wouldn’t) then you might spot something isn’t right.

But there is no way to tell if your microphone is being used.

Before you know it the photos, videos, and private conversations of thousands or even millions of people could have been made available for public viewing on the internet.

As shown with the AOL search data scandal, any other unwanted publication of data on the internet is very difficult, or often impossible to get removed.

Think you are safe from prying ears and eyes when away from your computer? Think again, modern mobile phones have cameras, a microphone and an internet connection. There have not been very many instances of mobile phones viruses – yet, but this is an areas that criminals are likely to target more in the future.

Internet censorship

Censorship on the internet is increasing. As well as countries that openly practice internet censorship, you might be surprised to hear of internet censorship being introduced in countries such as Australia and New Zealand.

One of the internet’s big strengths has been to allow information to move freely from country to country. For how much longer will this be the case?

Reporters without Borders have a good PDF of internet enemies on their site, and Wikipedia have a comprehensive starting page on internet censorship.

Made to pay for illegal music and film downloading

Have you ever illegally downloaded a song or a film? Or have you shared a song or film with other via websites such as BitTorrent?

If you have, then music and film industry bodies such as the RIAA or MPAA may one day be getting in contact with you.

They are very keen to stamp down on all pirating activities and have launched many prosecutions against individual users. There has even been a case of someone being jailed for sharing a video.

You may wonder how they would ever find out. Unfortunately for you there are companies such as BayTSP who are employed by the copyright holders to track illegal downloads on their behalf. They can build up huge databases of what IP addresses are downloading what. All the copyright holder then has to do is to make the relevant ISP hand over the details of who was using that IP address at that time and they can soon make a prosecution.

Many people have already received demands that require them to pay compensation or face prosecution.

Don’t go round thinking the internet is anonymous. Everywhere you go information about what you do is being recorded. It only takes one company with sufficient motivation (such as an expected monetary payoff) to be able to piece the bits together and identify you.

Windows Update hacked

Windows Update is Microsoft’s solution for pushing updates and patches to millions of Windows PCs all around the world.

adsl microfilter

Most people have their PCs configured to automatically download and install all critical updates that Microsoft issue.

What if the ‘bad guy hackers’ managed to hack into the Windows Update mechanism and insert their virus into the Windows Update system so that all Windows PCs around the world automatically downloaded and installed it before Microsoft notice?

Once installed the virus could create havoc on a scale not seen by any other virus. A denial of service attack launched from the entire world’s Windows PCs could bring the internet to a complete standstill for a significant time. The damage would take a lot of effort to fix.

Ultimate doomesday

What if using the Windows Update hack the bad guys were really evil. What if instead of just installing spyware, or using the PCs as a botnet the bad guys decided to nuke them. The Chernobyl virus wrote over the computer’s BIOS, and over vital parts of the hard drive.

If it managed to infect the computer and corrupt the BIOS and hard drive in this way then the computer would need to be taken in for repair, and there might be a significant loss of data even after the repair.

Millions or hundreds of millions people could be left without access to their computers. This kind of virus would be more likely to affect home or small business users, as medium or large businesses don’t usually have automatic updates turned on. They’ll roll out the patches only after they have tested them.

This kind of virus could have enormous global impact, but it could still be worse.

If the bad guys managed to find a significant zero day exploit on several different versions of Windows, and managed to find a way to covertly spread it, then they could go for a total global infection. If the bad guys were patient and waited for the infection to reach a critical mass before activating it then they could simultaneously nuke the majority of internet connected Windows PCs at the same time.

What then? It is hard to imagine what would happen to the world if most of their desktop computers were wiped out in this way.

Of course some lucky people would have UNIX/Linux/Mac machines, and they’d be alright – unless the hackers were really good and used a simultaneous exploit on those as well! Users of non-Windows machines shouldn’t be too smug about the security of their computers. There are many examples that have shown that non-Windows machines are riddled with security holes. They only stay virus free because the hackers attention is focussed on the Windows boxes.

Links for the paranoid

The best way to avoid viruses and spyware is to apply common sense. Nowadays most malware is getting on computers through social engineering, or people being careless. I did write a post about anti-malware software but it is now a bit out of date. These days I use Avast, Windows Security Essentials, Spyware Blaster and Trusteer Rapport.

Scroggle will allow you to search Google without them being able to link your search queries to you. Google have an SSL encrypted version of the search tool, which will prevent your searches being intercepted by your ISP, or by people sniffing your unencrypted WiFi connection if you aren’t using an encrypted connection.

For more comprehensive anonymous browsing Anonymizer.com will help.

If you are worried about your web cam being used to spy on you then covering the lens with blu tack or a piece of paper will work. Be careful if you use something sticky like blu tack. When you close the screen it might stick to the main surface of your laptop. And when you then open it again you could end up ripping the screen off!

Preventing the microphone from being used is harder – if there is a physical microphone plug on the laptop then plugging in a 3.5mm adaptor should physically disconnect it.

To solve your worries about losing data which is stored in the world’s data centres all you have to do is make sure it is backed up – which you should be doing anyway.

For people who are worried about being sued for pirating music and DVDs; I’d suggest a simple solution. Buy your music and DVDs instead of pirating them! They aren’t that expensive if you get them from somewhere like Amazon. And you’ll get a warm and fuzzy feeling that you are supporting the people employed in the music and film industries!

Have fun on your computers, and stay safe!

What does one million pounds look like?

Sunday, May 9th, 2010

If you’ve ever wondered what a million pounds (£1,000,000) looks like this post may help. Unfortunately I don’t have a million pounds, but I do have one single twenty pound note. Here it is:

twenty pounds

I also have a ruler, a calculator, and a copy of Paint Shop Pro. I’m therefore going to create a million pounds out of £20 notes. To do this I need to know the dimensions of the £20 bank note. Each one is 149x80mm with a thickness of 0.113mm. A stack of 100 notes with a value of £2000 will therefore be just 11.3mm high. Or 1.13cm if you prefer.

Here is £2000 with some mystery legs to give you a sense of scale.

two thousand pounds

Of course your £2000 stack will only look like this if you use fresh new banknotes straight off the printing press. If you build the stack out of used banknotes it won’t look so neat because of all the crinkles and folds.

What does one hundred thousand pounds look like?

Next what might one hundred thousand pounds (£100,000) look like? A bit like this photo, 9 stacks, each with a bit over eleven thousand pounds in it. A nice block of money I’m sure you’ll agree.

one hundred thousand pounds

What does one million pounds look like?

So what does a million pounds look like? I’ve built my million pounds out of 25 blocks of £40,000. Each of these blocks is 22.6cm high. So my million is about 45.2cm high with a single block of £40,000 at the front. One million is made of 50,000 £20 notes.

one million pounds

What if instead of being in a big block, all the notes were in a single pile? If that were done we’d have a stack of notes 5.65m high. To put that in perspective I put the stack next to a London double-decker bus. You can see that one million is a bit higher than a bus.

million pound stack and bus

There are a few more all important questions to answer.

Would one million pounds fit in a brief case?

If we imagine a film or crime drama where the villain brings a brief case full of bank notes to a meeting how much would fit in there? If it is filled with £20 notes then we could fit about £100,000 in a brief case.

If we are dealing with £50 notes then we could fit about £250,000 in a slightly bigger brief case.

As for bringing a million pounds in a brief case – it isn’t going to work.

Would one million pounds fit in a suit case?

With a suitcase you can transport much more serious money. You can definitely fit a million in a suitcase using £20 notes. And using £50 notes you can easily lug two million pounds around.

What would one million pounds weigh?

One million pounds using £20 notes would weigh about 50kg! You’d have to be pretty strong to be able to carry it. If you put it in a suitcase and tried to check it on to an aircraft you’d be racking up some serious excess baggage charges. Luckily you’d have to cash on hand to pay for it!

Using £50 notes your million would weigh about 22kg. This would almost fit into your usual 20kg airline allowance. And if you put some of the notes in your hand luggage you’d completely escape any excess baggage charge.

If we go back to the suitcase example £100,000 of £20 bank notes in a briefcase would weigh about 5kg. If you add in the weight of the briefcase you still have a fairly portable brief case of cash.

What are the bank note dimensions?

For reference:

£20 – A twenty pound note is about 149x80mm, 0.113mm thick. About 1g in weight.

£50 – A fifty pound note is about 156x85mm, 0.113mm thick. And about 1.1g in weight.

Filling in the Inland Revenue self assessment online tax form

Thursday, April 22nd, 2010

If you need to file a self assessment tax form in the UK to work out your income tax you have a number of options. You can fill in a paper tax return, do the online return, use some 3rd party tax software, or pay someone else to do it for you.

I’m going to show you what the HMRC online self assessment forms are like, from the beginning to the end.

To start off you log into the system and choose the option to ‘File a return’.

01 self assessment overview

You’ll get an explanation of who can use the online self assessment, and who can’t. As long as your financial isn’t too exotic you should be able to use the online tax forms.

02 self assessment welcome page

To get started you’ll need to confirm some personal details about your name, national insurance number, etc. Most of these should have been filled in for you already, so you only need to update them if necessary.

03 self assessment tell us about you

In the ‘Tailor your return’ section you need to enter some high level details about your financial situation, such as whether you are employed, self-employed, have received bank interest, have other income, and more. The answers to these questions will set up which parts of the form you’ll see later on. Don’t worry too much about getting your answers correct first time. Up until the point that you make the final submission, you can go back and change any parts of the self assessment form later.

04 tailor your return

06 3 tailor your return

If you are stuck on any section you can click on the green question marks next to the boxes, and you’ll get a pop-up with help messages in it.

05 help screen

Got to the next page (1 | 2 | 3)


Wrist and arm pain when using a computer

Monday, April 12th, 2010

Like many people who have to use a computer all day, every day, as part of their job, I find that I regularly get a painful or numb feeling in my wrists and arms.

This is my story of what I’ve done to try to make that numbness and pain go away. I’ll add a usual disclaimer, pointing out that I’m not a medical expert, this is just personal account, and that you should get advice from a professional if you have any kind of pain.

Office work is dangerous

It all started when I began my first job in an office. People may think that working in an office is safe for your health. My experience is that it is not!

Over the first weeks and months that I was there I started getting a feeling of numbness in my wrists when I was sat at my desk using the keyboard and mouse. I also started getting knee pain, which is something I have previously written about.

DSE assessment

After this had been going on a while I decided to request a DSE (display screen equipment) assessment. Fortunately this easy to do at my company. Within a week I was visited by someone from a DSE company who looked at how I was sitting, and how I was using the keyboard, mouse, and monitor.

He made adjustments to a few aspects of the way I sat at my desk, including raising the height of my monitor, and making a few adjustments to my chair.

He raised my chair to make sure that I didn’t have to tilt my arms up to use the mouse and keyboard. Because of my raised chair, I had to get a foot rest as well to keep my legs comfortable.

He also gave basic advice such as telling me to take regular breaks from the computer.

To help me remember to take regular breaks I installed the free SCIROCCO Take a Break software which I configured to pop up a reminder every half an hour.

scirocco take a break

Learning to live with the numbness

I got the numb feeling in my wrists and arms every day I worked at the office, but I learnt to live with it. The severity of the problem wasn’t improving, but it wasn’t getting any worse either.

I’d found that the problem was always much worse if I worked with bare arms. If I had the sleeves of a jumper covering my arms the pain or numbness wouldn’t be as severe or as noticeable.

uniqlo jumper

One theory I have for this is that when wearing a jumper, the extra fabric around my arms acts like a cushion, preventing me from constricting any of the nerves in my arm as severely as when they rest on my desk. This is just my personal theory, and I can’t give any scientific proof that it would work for anyone else.

You don’t always want to wear a jumper when it is hot so I discovered that I got the same improvement if I just wore fabric wristbands. You’ll find these in clothes shops that sell accessories.

fabric wristbands

Wrist braces, pill popping, and exercisers

During this time I tried a number of other things to try to reduce the pain. I gave wrist braces a go, but I found them to be very restrictive for my wrist and arm movements. I much preferred using simple fabric wristbands as I spoke about above.

wrist support for wrist pain

I tried using a number of different pills. I tried multi-vitamin tablets, cod liver oil, and glucosamine sulphate. It is possible that they helped with my general health, or even helped with my specific wrist problems, but to be honest I didn’t notice any difference when I was using them.

vitamins glucosamine sulphate cod liver oil

I also tried using wrist exercisers, but I didn’t find they improved anything. If anything I found that my wrists felt worse after using these.

wrist exerciser

Electric conduction tests

After many years of putting up with my wrist problems I decided that I really should see my doctor. When I went to see him he asked me some questions, took a look at my arm, and then said he would refer me to the hospital to have some electrical conduction tests done on my right arm (the right was worse than the left). He said that I might have a mild form of carpel tunnel syndrome.

At the hospital they attached an electrode to one finger at a time, put some salt gel on my arm, and then measured how easily electricity conducted through the nerves. They also did tests that caused my fingers and arm to twitch as a result of the electricity.

I got the results a week later which said that my nerves were fine, and if anything was wrong with them it was very mild.

Physiotherapy for my wrist pain

I had private health insurance with Cigna from my employer, so I called them up to ask if I could see a physio about my wrist and arm pain.

They agreed, and authorised six physio sessions for me.

The physiotherapist started by asking about my problem, and then doing basic manipulations on my arms to judge what the problem was. She though the problem was caused by tightness in my muscles, not just around my arm and wrist, but also in my shoulders, neck, and back.

She explained how the nerves are connected, and how problems in your back can also affect your arm and wrist.

Over the weeks she did deep tissue massage on my arm to loosen up the tissue structures. This was quite painful, and would leave me with red and purple bruises.

She also did massage on my shoulder and back areas to loosen any tissue structures that might be constricting the nerves which lead to my hands.

As well as the deep tissue massage she showed me a variety of stretches. These weren’t just hand stretches, there were stretches for my back, arm and neck as well. She was trying to work on the whole length of where the problem might be coming from.

Another DSE visit

The physio wanted to see how I used my computer equipment. As my employer wouldn’t pay for an onsite visit (it wasn’t covered by the insurance), they arranged for the DSE assessor to visit again.

He once again looked at how my desk was set up. He made an additional recommendation. He said that I should change from using a full size keyboard to a mini-keyboard. He thought that the amount of travel my right arm had to do from the mouse to the keyboard might be causing problems.

The extra travel distance is caused by the numeric keypad of a full sized keyboard. I’ve highlighted in red the amount of travel when you use a full sized and mini keyboard in the photo below.

amount of hand travel with mini keyboard

He took photos of me using my equipment which I was able to send to the physio.

Back at the physio

The physio was able to use the photos to make another suggestion. She thought that my mouse was causing me to twist my arm in an unnatural way. She recommended an ergonomic mouse.

She had a number of different ones which I was able to borrow, and after experimenting I settled on a vertical grip mouse like the one in the photo below. I bought it from Helashop (who don’t seem to exist anymore), but there are loads of other ergonomic mice available from Amazon as well. I’d advise you to try them before you buy, as they can feel quite strange at first.

ergonomic mouse

In the next photo you can see the difference one of these mice makes in the position and angle of my arm, as opposed to using a standard mouse.

wrist angle changes with ergonomic mouse

Two mice are better than one

I made a further change in my desk. I started using a second mouse. For the left hand I used a standard mouse, and I used the ergonomic mouse for my right hand. It does take a while to get used to using a mouse with your other arm, but you can do it if you practice for a few weeks.

two mice and mini keyboard

By using two mice rather than one you can spread the load more evenly over both arms, rather than having your dominant arm take most of the damage.

After 8 years, what worked, what didn’t

I’ve had knee and arm numbness for 8 years now, at varying degrees of severity. First of all these are the things that I found didn’t help me.

  • Wrist braces – I found these too tight, and constricting for my work.
  • Vitamins, Cod liver oil, Glucosamine – I didn’t notice any difference through using them.
  • Wrist exercisers – No help to me. They seemed to make things worse.

Here is what helped me.

  • DSE assessment – If you use a computer all day then make sure it is set up correctly. Any slight problems in the way you use them build up over time. Ask your employer if they can arrange for an assessment.
  • Physio – Physio was very helpful, both to help me understand the causes of the problem, and to help with the treatment. It was definitely worth treating the back and shoulders as well as the specific wrist area.
  • Stretching – I found the wrist, shoulder, neck, and back stretches reduced the severity of the problem. If you can’t motivate yourself to stretch regularly; a yoga, pilates, or dance class may help you.
  • Wearing a jumper or wrist band – This isn’t a recommendation you often hear, but I find that keeping my wrist covered by fabric helped a lot.
  • Ergonomic mouse – I did find my right arm was more comfortable when using the ergonomic mouse.
  • Using two mice, left and right – Two is better than one as the load can be spread between the two arms.
  • A mini keyboard – The reduced amount of travel of my arm between the mouse and mini keyboard help as well.
  • Computer timer – I recommend you have a timer on your computer to remind you to take regular breaks. It is very easy to lose track of time, and end up spending hours using the computer without a break.


Takamatsu Japan, what to do there

Monday, December 21st, 2009

Takamatsu is not a city that many people think of when visiting Japan, but it is the city that I happened to find myself in for a year.

It is in the Kagawa prefecture of Shikoku Island. Shikoku is the smallest of the four main islands that make up Japan and is positioned south west of Osaka. Shikoku Island is most famous for its 88-temple pilgrimage. It is joined to the mainland by a number of bridges, including the Seto Ohashi Bridge, one of the longest in the world.

Takamatsu is situated on the North side of the Island and has a harbour area that faces into the Seto Inland Sea. The city has a population of around 400,000. It has a large shopping, restaurant, and nightlife area.

Ritsurin Park

Ritsurin Park is a 75-hectare park of 6 ponds and 13 small hills that has been designated as a “national place of special scenic beauty”.

ritsurin park takamatsu

Inside the landscaped park are a huge variety of plants, trees and flowers. Pick up a map and it will show you a few suggested walking routes.

The park faces Mt. Shiun which makes it easy to get your bearings. Look out for the famous view of Bairin-kyo Bridge. You’ll also find plenty of colourful Koi fish in the large interconnected ponds and lakes.

If you have more time there is a tea house where you can be served Japanese green tea (there is an extra charge for this). For more information see my Ritsurin Park page.

Takamatsu Castle / Tamamo Park

Takamatsu’s castle, properly called Tamamo Castle is located near the harbour area of Takamatsu. It is one of the “three water castles” of Japan, taking its moat water from the Seto Inland Sea.

tamamo castle takamatsu

The castle is nice, but you will find more impressive castles elsewhere in Japan. However you should still go here to have a look, and have a walk through the Tamamo Park grounds.

If you are in Takamatsu in during late October / beginning November then Tamamo Park is the location for a festival of chrysanthemum flowers. You may also find Bonsai trees on display.

Covered shopping streets (shotengai)

The main shopping area of Takamatsu consists of a number of covered shopping streets. Take a walk along Tamachi, Minamishinmachi, Marugamemachi, Kataharamachi, Hyogomachi, Lion-Dori and Tokiwamachi. You’ll find hundreds of shops and many restaurants.

There are clothing shops, household goods, Udon restaurants, book shops, souvenir shops and more. This is an especially good place to shop if it is raining as you can get across large areas of the city without being too exposed to the elements.

Harbour and Sunport area

Takamatsu is a harbour city and the relatively new Sunport area has been built to show it off.

takamatsu harbour sunport and lighthouse

Go to the 8th floor observation deck of the Sunport building and you’ll be able to see across the Seto Inland Sea. In the Sunport Tower building you’ll also find some good restaurants, coffee shops, clothes shops, and more.

Have a walk along the harbour area and you can see the regular passenger and car ferries sailing to and from the harbour. It is worth taking a walk along the harbour promenade to the red lighthouse, which sits on at the end of a long pier.

seto inland sea takamatsu

From the harbour area you can get a ferry to one of the many islands that are close by such as Naoshima, Shodoshima, Megijima and Ogishima.

Naoshima Island

Naoshima can be reached by ferry in less than an hour from Takamatsu port. Once there you should get a bus to the Art House Project and buy a ticket which will allow you to look at art installations which have been placed in a number of old Japanese buildings.

There is also a very small James Bond museum on the Island if you are a fan.

naoshima island

Shodoshima Island

Less than an hour be ferry will get you to Shodoshima Island. I’d recommend going to the Kankakei Mountain where you can either get a cable car or walk to the top. Once at the top there are viewing areas, food, shops, and more walking paths.

shodoshima kankakei mountain

Yashima flat top mountain

A short Kotoden train journey from Kawaramachi station will get you to the base of the Yashima flat top mountain. From there you can either walk up or get the bus. On the top you will find Yashima aquarium with its many types of fish, as well as a dolphin and sea lion show. There is also a great view across the Takamatsu harbour to see, and a temple – one of the 88.

yashima flat top mountain takamatsu

There are other attractions around Yashima as well such as the folk museum and a shrines and temple. You can read more about the Shikoku-Mura folk museum here.

Hill walking

Takamatsu is surrounded by hills. Some of them are easy to walk up. Mount Inari is in easy walking distance from the town centre. The nearest station is Ritsurin Koen Kitaguchi. The walking paths aren’t very visibly marked. The best thing to do is to walk around the hill until you find the path. I found a path entrance on the North side of Mount Inari.

Walking up took about two hours as I took some wrong turns – the route is not very visible so a bit of trial and error may be needed. Once at the top you get a small view of parts of the city – note that there are many trees at the top obscuring your view so go up for the fun of the walk – not the view.

mount inari takamatsu

You might want to note that there were very few other people in the area so if you have an accident you’ll be in trouble! And as the hill is covered in tall trees no one will see you. I’d suggest you don’t do a walk like this alone – and make sure you do it on a dry day as some of the paths can be slippy.

Other hills and mountains in the area are likely to be walkable if you do a bit of exploring. Certainly a walk up Mount Yashima will give you a great view of the Takamatsu harbour.

88 temple pilgrimage

Shikoku Island is famous for its 88 temple pilgrimage. The temples are scattered all over Shikoku Island, however quite a number of them are in easy reach of Takamatsu. If you go to look at any of them keep a look out for the pilgrims who will be dressed in white.

nagaoji temple

Kotohira – 1400 steps

Take the Kotoden train to Kotohira station and you will be able to see one of the most famous Shinto shrines in the country. To reach the main shrine you will have to climb 785 steps up Mt. Zozusan. Another 583 steps will take you as high as you are allowed to go.

Along the way you’ll pass a number of shops, shrines and statues. There’s a great view from the top. There are more photos and information on my Kotohira page.

Takamatsu festivals

There are quite a number of festivals and special events in the Takamatsu area which are worth keeping an eye out for. These include a Winter festival, the Shionoe Firefly Festival, the stone lantern road, and every three years the Setouchi International Art Festival.

Travelling around Takamatsu

Takamatsu is very easy to get around. The town centre and Sunport areas close together. Walking is the most convenient way to get around the centre. There is a local Kotoden tram network that will take you further outside of Takamatsu. Takamatsu mainline train station will allow you to get trains around Shikoku and also onto the main Japan Island. Taking a JR train over the Seto Ohashi Bridge to Okayama will give you great views of the Seto Sea.

If you are likely to be using the local trams frequently (along with the Kotoden local busses) then it may be worth getting an IruCa card. The IruCa card is a smart card that you ‘charge up’ with credit. You can then use the Kotoden tram and Kotoden busses without needing cash.

On the trams you’ll need to swipe your card over the scanner at the start and end of your journey. At larger stations such as Kawaramachi there are ticket barriers to make sure you do this. At smaller stations such as Hanozono there are IruCa readers on the platform. When you leave the train the train’s ticket inspector will watch you to make sure you swipe out! Google Maps knows the timetable and costs of the Kotoden trams so if you do a route search between two destinations in central Takamatsu it will give you tram information.

On the Kotoden buses you’ll need to enter by the door in the middle of the bus. You’ll then have to touch the IruCa reader by the door with your card. When you exit through the front door of the bus you’ll have to touch the card on IruCa reader at the front of the bus. You can pay by cash as well – just get the numbered ticket when you enter. On Okawa buses you’ll need to get a ticket on entering, and pay when you leave. There is timetable information on the Kotoden website and the Okawabus website, but it is only available in Japanese.

iruca card takamatsu

You can also use the IruCa card to pay for items in some shops and for items in some vending machines displaying the IruCa logo.

If you want to travel further away (Tokyo, Naha, Kagoshima or Seoul) then you might want to read my Takamatsu Airport page.

Eating in Takamatsu

I have reviews of some vegetarian friendly restaurants in Takamatsu that you may be interested in reading. This includes Italian, Indian, and an Udon restaurant.

Hotels in Takamatsu

I’ve never stayed in a Takamatsu hotel (as I’ve been living here), but my parents tell me that the Dormy Inn Hotel was very good, and reasonably priced. It is well positioned in the centre of the city, near the covered shopping area.

Takamatsu cinemas

The largest cinema is the Warner Mycal multi-screen cinema at the Aeon shopping centre (was a Saty shopping centre prior to March 2011) which is East of Takamatsu between Sunport and Yashima. The Warner Mycal Takamatsu schedule page is here. The nearest Kotoden station is Okimatsushima. There is a smaller cinema just off the shotengai in the Kawaramachi area.

Many Western films are shown in the original language with Japanese subtitles. Look out for the ones that have this ‘subtitles’ symbol 字幕. If the listing doesn’t have this symbol then the film will probably be dubbed in Japanese!

Shopping centres and Western food

Two of the larger shopping centres are Youme Town which is South of Ritsurin Park, and Aeon which is to the West of Takamatsu. You can get buses to both of these places from Sunport and Tenmaya.

In Aeon is a Kaldi Coffee Farm shop which sells some non-Japanese foods that are hard to find (nachos, biscuits, salsa sauce). Some other items like chick peas are cheaper here than elsewhere.

Keeping fit

Takamatsu is extremely bike friendly. It is very flat, you can cycle on the roads or pavement, and drivers are (almost always) considerate to you. You can rent bikes for ¥100 from a number of bike hire places around the city – there’s one near the main station.

If you are looking for yoga then there is a bilingual (Japanese/English) yoga class taught by Michi that I can recommend.

Takamatsu has a Round 1, where you can do bowling, skating, and other racket sports. I have some Round 1 bowling information on the site.

Takamatsu long stay information

If you are staying in Takamatsu for longer than a normal holiday then there are a number of useful places, and organisations that can make your life easier.

Takamatsu is home to Kagawa’s International Exchange Centre, also know as the I-PAL Centre. Here you can do Japanese classes very cheaply, get access to foreign magazines and newspapers, and take part in their Japanese language salon where you can practice your Japanese with local residents. They also can offer interpreter and legal help if you need it.

If you don’t have your own internet access then you should check out e-topia in the Sunport Tower. Here you can use their computers for surfing the web (you just need to fill in a quick form to do this), or if you have your own laptop you can sign up for their secure WPA2 encrypted WiFi access. You might need to take a Japanese speaker with you in order to be able to get through the sign up process.

Alternatively there is an internet connected computer in the library in the I-PAL Centre (they have WiFi too), and you will find free WiFi access near the North end of the covered shopping arcade.

For weather information look at the Japan Meteorological Agency page for Kagawa.

If you are looking to meet new people then you should join the newly formed Kagawa Foreigners United Network (K-FUN) who are organising events in the Kagawa area.

For practical information on living in the Kagawa prefecture have a look at the International Affairs Division website. My guide to alien registration has a few specific details about registering in Takamatsu.