Jonathan's blog

As I cycled to work this morning, I had a crazy idea. It’s just daydreaming and will probably never happen, but it’s fun to think about. I’ve already posted this idea to the linux-audio-user mailing list in case anyone there has any insights on synthesising/sampling engine sounds.

I want to measure how fast I’m turning the pedals on my bike (the cadence) and synthesize/sample the sound of an internal combustion engine.

As far as I can work out, there are three major parts to this.

1. A sensor that can measure my cadence. A simple magnet switch that triggers once a revolution won’t be enough to measure the cadence with sufficient resolution, since my cadence is usually between 50 and 80 rpm, and I will need to sample more than once a second. I would probably need to mount multiple magnets spaced equally around the chainwheel and have a single sensor on the frame. Then I have to get it to supply this information to my control program.

2. I need a control program that can read in the input from my cadence sensor and convert a cadence reading of “66 rpm” into a frequency that should be sampled/synthesised, e.g. “500 Hz” (I’m making these numbers up). It will also need to be able to somehow smooth out the readings, perhaps by interpolation, so when I accelerate, the sound of the revs climbing doesn’t increase in obvious steps. It could also have other logic, e.g. when my cadence is 0 rpm, the sound of the engine is idling rather than off.

3. I need a synthesiser or sampler that can take an input from my control program and make the sound of an engine (or more likely, a sine wave to start with). I’ve never sampled or synthesised on a computer before but this engine-specific sampling technology already exists in video games, such as torcs.

I have absolutely no idea why I would want such a device – just for the fun of building it, I guess. I would like it to work in realtime (rather than later generating the soundtrack from recorded cadence data). The thought of sitting at the traffic lights with my earphones in and then hearing the mighty roar of a V8 as I pull away would be really satisfying…

Any thoughts – useful, interesting, humorous, or otherwise – are welcome!

I just spotted that my Nagios/RRD graphs of my home server are showing a strange correlation.

From these graphs, it seems that the higher the outdoor temperature, the more free memory the system has available. I’m sure this is just a coincidence, though…

Outdoor temperature

Free memory

Perhaps my job as a mobile IT specialist is getting too much for me.

Last night I had a dream that someone configured my alarm clock for push notifications and then signed me up to a high volume mailing list.

When it went off this morning, in a half-awake state I irritably tried to remember how to configure my push mail settings (aka “snooze”) and went back to sleep. Repeat in five minutes. Ugh.

Perhaps it’s time for a holiday!

I’ve now had an iPhone 3GS for a couple of weeks, and it seemed only right to write something about it. This is not a review – there are many, many other reviews of the iPhone out there. This article is just a collection of my own thoughts, and a few comparisons to my other current smartphone (an HTC Magic) and my old smartphone (a Sony Ericsson P1i).

It might sound like a daft thing to complain about, but the iPhone doesn’t have an “alert LED” to warn you when there’s a text message or voicemail waiting. The P1i and the Magic both have this – and it’s great because you can see from across the room whether you’ve missed a message. I didn’t realise how much I used it until I realised that the iPhone doesn’t have such a feature. It’s annoying to have to walk over, pick it up and unlock it to check.

The iPhone suffers from poor battery life. Admittedly I tend to keep wifi and GPS turned on all of the time, but with an average day’s use (0 phonecalls, a handful of texts and maybe 30-60 minutes of app usage and web browsing) the battery gets down to 25% and I have to recharge every night. It’s OK provided I’m able to charge it every night. If I was going camping, I’d make the effort to turn wifi and GPS off, and maybe even get 2 days of use out of it! My P1i lasted for days before it needed fresh coal, and the Magic lasts for a few days between recharges with wifi enabled.

Some people have also complained that the iPhone’s battery can’t be changed by a mere mortal and have cited this for a reason for not buying it. I agree to a certain extent, but the battery isn’t likely to wear out for a couple of years, and by then I’ll be wanting a new phone anyway.

This next item might be seen as a pro or a con – the iPhone doesn’t really have many options. This is probably OK for most people, but it is not as configurable as the Magic. If an app or an aspect of the OS works the way you like it, then good. If not, it’s a bit tough. The Magic is inherently more geeky and everything has options. Having said that, the options aren’t in your face and are not intimidating for novice users.

The browser, as many have noted, is excellent. I won’t go into detail about it. The browser on the Magic is also good at rendering pages properly, but unfortunately lacks a multi-touch interface. This means you can’t do the pinch-zoom gesture, among other things. Other HTC handsets have multi-touch interfaces, though.

A minor annoyance with the iPhone is that it has to be registered with iTunes, and must be connected to iTunes when you want to update the firmware. It might not affect most people (especially if they already use iTunes for listening to music), but it could be annoyance for those who don’t want to install an unnecessary music player, and especially for me, as I had to build a Windows virtual machine to install iTunes. In contrast, the Magic simply receives its updates over the air, using 3G or wifi.

I prefer the feel of the Magic in my hand over the iPhone. The Magic is a bit smaller, a bit lighter and a nicer shape, I think. Doesn’t make a huge difference though. By this point, I’m just nitpicking.

Both devices have good screen, good onsreen keyboards and generally similar. The iPhone is a bit slicker, but I think my favourite phone out of the two is the Magic. I’d like it even more if it had multi-touch, too

Since getting my iPhone 3GS, I’ve been playing with a few apps. Today I tried one called Cyclemeter, which is a GPS tracker and can provide some interesting stats about your cycle rides.

I set it to track my journey to work (Speedwell – Clifton) and was quite interested by the elevation graph in particular. (N.B. this route is slightly shorter than my usual one, since the Bristol-Bath cycle path is currently closed near Lodge Causeway, so I’ve been taking a shortcut on main roads).

I’ve included some iPhone screenshots of my results:

Map of my route to work

Graphs of my route

Key points:

• I start at home, taking the roads
• At 2km, I join the Bristol-Bath cycle path at Rose Green Rd. You can see a dip in my speed where I stop and push my bike through the gate.
• Most of the cycle path is gently downhill towards the city centre
• At 5km, I reach the end of the cycle path and proceed through Old Market. It’s a bit stop-start in traffic.
• From 6km onwards, it’s a steady uphill climb (Woodland Road today, sometimes St Michael’s Hill instead) from about 85m to almost 160m above sea level!

This week, my phone contract came to an end and it was time to say goodbye to my old smartphone – a Sony Ericsson P1i. I thought it fitting to say a few words. Don’t confuse this with a review for a 3-year old phone – this is more like a comparison between the early days of smartphones, and the handsets you can buy today.

Sony Ericsson P1i

I’ve had the P1i for 19 months, during which time I have used it every single day – so I know it pretty well. I originally chose it because I wanted a smartphone – something that could handle web and email. My previous phone had been a Sony Ericsson K800i, which had GPRS, and a basic email client and web browser. It was slow, and it never really worked properly. I guess that’s what you might expect given that it wasn’t a smartphone

So I chose the P1i because it boasted 3G, wifi, a decent web browser, a more complex email client and other Internet-oriented features. It also had a QWERTY keyboard and a touchscreen with a stylus. There wasn’t a lot of choice because at the time, nearly all smartphones were sold intended for business, and the Apple iPhone had just been released but cost a weeks’ wages – even if you were the boss of Apple.

(I briefly owned a BlackBerry Pearl 8100, but it was so awful that I sent it back after 48 hours).

I had used a Sony Ericsson M600i at work, so I knew vaguely what I was getting. The P1i was pretty much the same, except with twice the memory, a newer OS, and wifi. When I started using it, I was excited that I’d be able to browse the web at will, read my emails on the move and never be bored again.

But my dream never quite came true. Why not?

The web browser

As mobile browsers of the day go, it was pretty good. It was an integrated version of Opera Mini which is a decent browser. It just doesn’t cut the mustard these days, as you simply can’t do without Flash or Javascript. Many sites simply don’t work.

Like today’s smartphones, it had options for portrait or landscape viewing. Unfortunately, you have to go into a menu to switch your view.

There’s no automatic resizing or scaling, so if you are looking at a “real” website, typically you only see the top corner and there’s an awful lot of vertical scrolling and horizontal scrolling before you find what you want. You also can’t scroll the way you can on modern phones such as the iPhone – by dragging the whole page with your finger. Scrolling was done using traditional scroll bars, which had to be dragged with the stylus (because they were too small for a finger).

And, as we now know, the concept of duplicating all web content in a special mobile web doesn’t really work. Sure, some sites offer mobile-friendly versions (e.g. Bristol University’s Mobile Campus Assistant) but it’s just not feasible to expect that you will never need to look at a “real” website on your phone.

The overall experience wasn’t great, and was mainly reserved for needing to find information on the move, such as store opening hours or a postcode for the sat nav.

The email client

If you only have an inbox folder, then you probably wouldn’t mind the email client on the P1i. However on my work email account, I have dozens of folders that incoming mail gets automatically sorted into. This is a nuisance on the P1i, as you have to go a couple of levels into the menus to choose which folder you’d like to view, and you have to go into each and every folder to see if it has any new messages in it.

I only really used the email client for writing emails when I was out and about.

The contract

Data contracts were expensive at the time I bought the P1i. They were most definitely targeted at business users, and my domestic mobile contract only included 1MB of data a month. That might let you view a handful of mobile websites, but it’s really nothing as soon as you start looking at “real” websites.

So I only used it in emergencies, because I knew that anything more would start to cost an arm and a leg.

The interface

The P1i has a QWERTY keyboard which is great for quick typing. It also has a jog-dial and some navigation buttons on the side, and of course the touchscreen. Depending the app or menu in question, you can sometimes use the touchscreen with a finger if you’re careful. Other times you’ll need the stylus.

The problem is that you have to keep switching between different input methods. The number of times I’ve started going through menus with the jog-dial, been forced to intervene by touching the screen, pressing the wrong thing, being forced to get the stylus out and then ended up typing awkwardly while also holding the stylus shows that the interface isn’t really mature.

Today, it’s practically impossible to buy a smartphone with a stylus (or a keyboard, for that matter).

The menu system

The main downfall of Symbian UIQ3 was its excessive complexity. Basic tasks, such as writing a new text message, would mean the user had to find their way through several levels of menus. Everything seemed to be hidden behind several menus, and there were pages and pages of options that would frighten most people. Consider also what I just said about constantly switching between input methods, and you might get an idea of the pain involved in, for example, changing the time zone when you go on holiday.

If this weren’t enough, the menus are slooooow and laggy. Opening a menu with several items might take a second, maybe longer. Opening your SMS inbox sometimes took as long as five seconds. That is an eternity in the world of technology users, and I often found myself hissing “come on!” at the phone when I was trying to do something.

Apps

Symbian was the forerunner of today’s smartphones in that it allowed users to download and install apps on their phone. There was no app store, and finding apps involved browsing the web endlessly and downloading them. It was a bit of a pain to do so on the phone itself, so I usually would find and download apps on my PC and transfer them to the phone using the cable or Bluetooth.

That’s fine for a geek like me, but the main problem was the fact that there were two Symbian based platforms – Sony Ericsson’s UIQ3, and Nokia’s S60. As always, there was a platform war and S60 won. It’s now quite hard to find any UIQ3 apps, and when most software developers say “Symbian” they mean “S60″.

Incidentally, Sony Ericsson are still making Symbian-based phones (such as the new Satio) but they now use S60.

The good points

Despite what I’ve said so far, it’s not all bad. The P1i did have some great features, such as:

• Hardware QWERTY keyboard. I was almost as fast typing on this as on a laptop.
• Relatively small size – it’s a lot smaller than my replacement phone – an iPhone 3GS.
• An LED on the base that blinks when you’ve got a text message or missed call. The iPhone really needs one of these!
• A battery that lasts a million years. So far, the iPhone has needed charging pretty much every night.

It’s been a good phone. It’s just time to move on now

Some years ago, my dad bought me a book about electronics, computers and robots from a jumble sale for 10p. It was published in 1984 and probably about 15 years out of date when I received it.

Today I came across it on my bookshelf back at my parents’ house, and there’s a double-page spread in it called Television and Video in the Year 2000. It has a picture of how a house might look in the millennium year.

Of course, speaking today with a decade’s hindsight, the house looks like something from Thunderbirds, but some of its predictions have indeed come true. Let me reproduce it for you here.

When you are grown up and your children are going to school, this book may not exist. In fact, schools as you know them may not exist either, and libraries with books may be museums. All this will happen because of television and video. Television was invented during the 1920s by John Logie Baird.

Studying by Television

Let’s visit a home of the future, say in the year 2000, and see what everyone is doing. Alice is 12 years old. She is not wasting time watching television; she is at school. That’s her teacher on the screen. She manages to see Alice once a week to check her written work, but not for long. By teaching on television she could have a thousand pupils in her class at once, but she doesn’t have more than a hundred. Alice likes to ‘go to school’ in the living-room where there is a row of flat screens against the wall. She wears headphones to listen to the teacher.

Alice’s brother, Peter, likes to work by himself in his bedroom with a smaller, personal screen. He is 20 years old and, although he lives in Britain, he’s studying with the Massachusetts Institute of Technology in the United States. His microcomputer and screen are linked by telephone to the local library. They are sending Peter a new article written in America. They received it overnight from the United States during the cheaper-rate computer time.

Work and Leisure

Dad has worked at home for the last five years, ever since his supermarket became fully automated. As supply manager for the supermarket, he checks the stock on the shelves every Monday morning visually through the closed-circuit television cameras. On his home screen he can also study the computer totals produced by the automatic check-out tills.

Mum is watching a live television programme. Her favourite daytime programme is the 24-hour European news station which the family receive through their satellite dish receiver on the roof.

Grandad Jones is the only member of the family who uses the video disc. At the moment he’s looking at a dahlia catalogue, and the video disc gives the best picture available on any system.

Granny Jones can hardly walk and spends her time watching the goings-on out in the street through the local closed-circuit camera system. The council originally set up the system to help stop burglaries.

I’ve also photographed the image from the book – apologies for the quality. I might even get round to scanning it one day. Click for a larger version.

A house of the future

So how accurate were the predictions?

Lots of  the things mentioned in the picture are easily possible with today’s technology. But few people do them because they are inconvenient or expensive, or simply a bad idea.

It would be easy to set up a videoconferencing system to allow pupils like Alice to have school lessons at home – but nobody would do it because it misses out on an awful lot of face-to-face contact. Peter’s use of technology to get hold of documents is more realistic.

Likewise the father working from home – it’s possible to install cameras around Tesco and have the stock manager working from home, but it’s useless and expensive.

As for the mother watching 24-hour live news and the grandad watching what’s essentially a DVD – spot on. But how bored must the granny be to sit there watching CCTV in her own street?

It seems to me the biggest omission of this futuristic house is the use of computers and the Internet – although lots of the video systems in use seem to do computer-like tasks. Each person in the house is using specialist equipment for each task, and each piece of equipment has its own source of external connectivity.

The beauty of modern computers is that they can do a wide variety of tasks, and that the Internet can be used to carry any sort of data, whether it’s a text document or a video stream.

The most saddening thing about that house is that nobody is talking to anyone else, and nobody has any reason to go outside. I hope that doesn’t come true!

About a year ago, I built a computer based upon the MSI P45 Neo3-FR motherboard. I chose it because it offered the ICH10R chipset with Intel Matrix fakeraid (but that’s a whole other story).

Overclocking

At the time, I was disappointed with the board because I was not able to overclock – not one tiny bit. My CPU is an Intel Core 2 Quad Q8200, and many people had reported large gains in overclocking while still running at a low temperature and with excellent stability.

Naturally I wanted a slice of the overclocking pie – partly for the fun and satisfaction for doing it, and partly to get even more bang for my buck.

The MSI BIOS included lots of settings for overclocking and overvolting the RAM and CPU. However I quickly found that any change whatsoever caused the system to not boot. Of course I started off conservatively and I tried all sorts of combinations but I never got the system to boot with any settings other than the exact defaults.

I was disappointed, but ultimately it wasn’t a big deal. The Core 2 Quad system was still a massive step upwards from my former system – an AMD Athlon X2. Even running at factory settings, it ought to be a very capable system.

Hackintosh

More recently, I’ve been wanting to build a Hackintosh. Fedora is a pretty damn good OS but there are one or two things it can’t do. For example, it doesn’t support my 35mm film scanner, and I can’t play my games.

OS X can do these things, and I greatly prefer it to Windows – even Windows 7, which is the best Windows in a long time, I reckon.

It’s a shame I hadn’t planned to make a Hackintosh before I bought the MSI motherboard, as I would have known that the most compatible boards are the Asus P5Q series.

Still, worth a shot with my P45-based board. I was able to get pretty far – I could get all the way through the OS X installer and it seemed fine. However, booting my freshly installed Snow Leopard caused it to freeze. I read millions of forums (not an exaggeration!) and it seemed that an incompatible BIOS might be the problem.

Some members recommended flashing with a custom-made BIOS, but I considered that a last resort. A sensible first step seemed to be to update to the latest MSI BIOS. Perhaps this alone would get my Hackintosh working and then I could ditch Windows as a secondary OS.

Live Update

MSI provide some Live Update utility that can allegedly update drivers and the BIOS from an ActiveX applet. Naturally it requires Internet Explorer on Windows, which as you can guess is not a combination I run on my computer. (However, I’ve never been able to make it work at all on any MSI-based system, Windows 7 or Vista)

Flashing the BIOS

The alternative is to download the BIOS image and the flashing program. It’s a Windows exe file. Of course Wine doesn’t help in this case because the program needs low-level access to the hardware. My only option is to boot from some kind of Windows media.

According to the readme file that came with the BIOS flashing program:

Boot your system from a Win98 or WinME boot-floppy.
How to make boot floppy in case your don’t have it ready:

• For Win9X, You can type [C:\ format a:/s] from the DOS prompt.
• For WinME, You can make a boot floppy from control panel–> add/remove program–>make boot floppy. Remove autoexec.bat & config.sys file if there’s any.
• For Win2000, there’s no way to make boot floppy, so you have to either use Win9X or WinME boot floppy.
• For WinXP, you can make a DOS boot disk. Go to Your Computer, right click drive A:, select Format, select copy system files.

If you do not have Windows ME or 98 to create the floppy you can make one on a friend’s computer.

Well that’s good, isn’t it. MSI officially recommend that I use a decade-old operating system on some hardware invented in 1983 (before I was bloody born!). Never mind the  fact that I don’t have a DOS boot disk, or a legacy Windows machine, or that my new computer doesn’t have a floppy drive. The solution? Oh it’s OK, I’ll go and ask a friend. Oops, scrap that – they all run BSD.

By chance, I have an IBM Thinkpad 760EL in my drawer, running Windows 3.11. Like all laptops of its era, it has a floppy drive, and being an IBM it still works perfectly. The battery life isn’t what it used to be but it still goes for half an hour and boots faster than a modern laptop running Vista. Of course it was easy to create a bootable DOS system disk.

Less straightforward was getting the BIOS program and image onto this bootable floppy. A straight-from-1991 copy of DOS 5.0 is unlikely to support USB mass storage, I reasoned. I managed to find an old floppy disk and connect it to my PC’s motherboard. My PSU didn’t have a floppy power connector so I had to make one by cutting up some old power cables and twisting the wires together. Finally I was able to boot into Fedora normally, mount the floppy disk and copy the files onto it.

Rebooting seemed to go OK and booting DOS didn’t cause any problems. After I got over my annoyance at the lack of tab completion, flashing the BIOS was easy. I powered off and on to make sure it had worked, and attempted to boot into Fedora.

Oh noes!

Apparently upgrading the BIOS didn’t go so smoothly after all. The new BIOS has more bugs than a dead dog in a New Delhi drain. It just…. doesn’t work.

• My RAM, formerly clocked at its native speed of 1067MHz is now running at 800MHz and can’t be made to go faster.
• My hard disks no longer work in AHCI mode. Random faults and reboots occur. I have to disable AHCI and go with IDE.
• Onboard networking seems to have disappeared.
• Any change to the hard disks (e.g. unplugging one, or swapping two over) cause the system to become non-bootable until the BIOS has been reset by pulling the jumper.
• The CPU fan and case fans now always spin flat out, regardless of what the options are set to. This PC now sounds like a Dyson.

Seriously, if I wanted a computer with IDE disks, slow RAM and no networking, I’d still be using the Thinkpad. The fact that it has been in my drawer for years is a good indication that I do not want these things.

I’ve given up on building a Hackintosh on this hardware. It’s a world of pain. All I want is my old setup back, like it was this morning. However, I haven’t yet worked out how to fix this problem. Probably reverting to an older BIOS is the best way to go – unfortunately I didn’t make a note of which BIOS revision I was running before.

I had a look at the changelog of the various revisions to see if there was any that jumped out at me as a good one to try. Unfortunately there are loads, and even when you get your head around the Engrish, the changelog makes for pretty worrying reading. It’s full of things like this:

Fixed system report incorrect memory size when install 4G memory.

I mean, how on Earth did the original version that didn’t work with 4GB memory get past testing and find its way into a release? The fixed version came over 2 months after the previous version, too.

I guess I’m going to have to try and find a suitable BIOS revision through trial and error, just to get my old system functionality back. And then when I’ve got the spare cash, I will be replacing the board with an Asus P5Q, which will hopefully work with a Hackintosh build.

Oh, and maybe it will let me use AHCI, too.

MSI are useless.

</rant>

Update

To my delight I just found out that the motherboard is two weeks younger than one year old – so eligible for a warranty return. This is a real rarity – usually stuff breaks two weeks after the warranty period.

Ebuyer say I’m only entitled to a replacement, not a refund. However they no longer stock the MSI P45 Neo3 (must have been an unpopular model – can’t think why!) so it’s likely that I’ll get store credit and be able to pick a motherboard that works

You might wonder what there is to discuss about bike lights. But in my several years as an urban commuter cyclist, and with my fascination for toys such as bike lights, I’ve made some observations which might prove useful to other cyclists.

What you need

Before you go out and buy a light, decide what your needs are. Choose a bike light to suit your needs (and budget, of course). If your daily needs cover two or more of these categories, you should consider buying either a light which ticks all of the right boxes, or two lights.

How to mount your lights

When you are riding in traffic and your lights are in flashing mode, I would recommend angling your lights directly forward. Most LED lights are not bright enough to dazzle other drivers, but pointing them forwards will make them appear much brighter, and will cause them to shine into the wingmirrors of cars in front of you.

If in doubt whether your lights are too bright, or inconsiderately aimed, sit in a car and get a friend to ride your bike at you

When riding with very bright lights, it’s plain rude to point them into driver’s eyes. Dip them like every other vehicle.

When riding on an unlit path, don’t use too much light because it dazzles other cyclists. Keep your lights aimed low. Flashing lights aren’t required here to attract attention, and the flashing can make it hard for oncoming cyclists to see.

Branded vs generic

As a student, I was strapped for cash and I would always buy cheap, generic bike lights from eBay. Now I have a job, I always buy Cat Eye.

In my experience, the cheap lights are usually similar in brightness but the beam pattern is never as good as a branded light. Most importantly, the cheap lights have very poor quality brackets which usually snap off long before the light breaks. One such light whose bracket broke has now been turned into a makeshift photography light, which I gave to my brother. I’m so generous!

Nowadays I almost always buy Cat Eye. They are the Coca Cola of the bike accessories world, and I’ve always found them to be consistently high quality in terms of the brackets and the brightness, beam pattern and battery life are excellent. They’re not the cheapest, but I reckon you’ll be pleased if you buy them.

Carrying spares

I think it is crucially important to carry either multiple lights or multiple sets of batteries with you while commuting. Especially with LEDs, it’s not always obvious when the batteries are running out so it’s easy to be caught short. If your lights run from AA/AAA batteries then it’s no problem to keep a spare set in the bottom of your bag all the time.

If you’re lucky enough to own a set of lights with a rechargeable battery pack, it’s not always practical or possible to carry a spare set with you. In this case you’d be wise to keep a spare LED light with you. Doesn’t matter if it’s a cheap one

Multiple lights

As well as keep a “spare” set with you, you might want to mount two or more lights on your handlebars.

I find that having two lights on the handlebars, both flashing, is a great way to attract attention. They never quite flash in perfect time and this effect is rather eye-catching.

It also means you can put out twice as much light when running in constant mode, which is great news if your commute takes you on unlit roads or paths.

I have 5 headlights on my bike. I have a pair of RSP Asteri 2 LED headlights which I use in flashing mode in the city and dim constant mode on the Bristol-Bath bike path. I have an extremely bright pair of Cat Eye ABS-35 halogens to be used on the unlit sections of the path when there are no oncoming cyclists. They have a thumb switch to turn them off quickly if anyone comes into view. And I also have a head-mounted flasher, a Cat Eye HL-EL400.

Head-mounted lights

Head-mounted bike lights are a controversial topic among cyclists and motorists.

I use a helmet-mounted front and rear light because they can be seen over the tops of cars in heavy traffic. It used to make me nervous that if I was currently being overtaken, the car behind the overtaking car might not be able to see my rear lights mounted in the usual place, below the saddle.

I also think it’s very versatile because you can choose to direct light wherever you turn your head. Part of my journey takes me along a stretch of road that has two lanes. Drivers frequently change lanes without looking sideways, where I often am. If I have a head-mounted flashing light, I can look into the car window, directly at the driver, and then they usually notice my presence.

However, one of my colleagues who drives (and also cycles) says he dislikes head-mounted bike lights because it is impossible to see a cyclist’s eyes and therefore the driver can’t always tell if the cyclist has seen the car.

I recently (mid October) moved my home server into my loft, as its constant noise under my desk was getting on my nerves.

However I found that with a large area of roof exposed to the sun (even the weak Autumn sun), and practically no ventilation the ambient temperature fluctuates enormously.

In October when it was a little warmer and a little sunnier, the temperature would drop almost as low at 10°C and almost as high as 30°C. An ambient temperature of over 25°C seems to drive my disk temperatures up to over 50°C. This constantly changing temperature with high and low extremes is a sure-fire way to break hard disks.

After Week 42, I opened the loft trapdoor, which went a long way to keeping the temperature more constant. Unfortunately it also makes the flat rather cold.

Now it’s much colder outdoors, I’ve closed the trapdoor again and the loft temperature seems pleasantly cool and reasonably constant. Today the temperature up there is a steady 13°C, although the sun hardly shone. That’s cooler than your average air-conditioned data centre – and all free thanks to the crappy British weather

Oh, and the 6 disks are now all between 25°C and 30°C.

• I’m measuring and graphing this using a TEMPer USB thermometer, using Nagios monitoring software with my own plugin and PNP4Nagios to draw the graphs.
• The “outage” between weeks 43 and 44 was caused by the shift from BST to GMT, apparently. I didn’t notice for a while, but restarting Nagios fixed it