More tea please.

Things to avoid in eBay listings

Potato crisp sold on eBay. CC licensed image from tofslie.

I reckon at least 90% of eBay listings have at least one of the following properties:

I think that when I visit an eBay listing, my heart rate is multiplied by the number of things it features from the above list.

Posted at 3:07 am on Wednesday 29th July 2009

Reactions in the kitchen lab

What happens when you realise you have all the required components to do some fun chemistry? This happens:

That’s sulphuric acid added to sugar. Warning: If you do this, do it in a well ventilated area… Sorry, I didn’t really think about lighting when taking the video! Also, my camera battery went flat, which is why there’s a rather sudden ending.

Here’s the result in a higher resolution for closer analysis:

Sulphuric acid and sugar

The rod of carbon didn’t noticeably grow any more after the photo. I measured the mug at 80 °C just after the photo.

Posted at 11:15 pm on Tuesday 28th July 2009

SR Subversion Codeswarm

I discovered codeswarm earlier, and had to run it on the student robotics subversion repository. Enjoy:

Can’t see the video? Try here.

Still can’t see the video? Download the Ogg Theora.

Posted at 8:20 pm on Tuesday 21st July 2009
One Comment


Banks. Some parts of them are good, some are bad. Let’s ignore their really bad repossessing-your-home side for a while and concentrate on what they’re good at. Many years ago, some guy realised that he could make money by storing someone else’s for them and then lending it to other people whilst they weren’t using it, and so on. Many highly confusing methods of extracting more money out of other money have since derived from this original approach.

Amongst some of those crazy things that banks do lies trading. Trading on the stock market. Some banks do automated trading, which has led to the acceleration of the stock market, with banks now requiring low latency links to stock exchanges to get a competitive edge.

Whilst firing money that they don’t necessarily have around at high speed using automated money cannons, the banks move their customers’ money around at extremely slow speeds. Many of them insist on sending their customers bits of processed dead tree every month or so to remind them about their money. When the customer wants to move her/his money into someone else’s account, they invariably have to wait a few days before it arrives.

Banks repurpose old cannons to fire money around. Photo under CC license — from flickr user StarbuckGuy.

So banks seem to have two faces. One face is highly automated and fast, whilst the other is slow, regularly resorts to paperwork, and doesn’t have a automatable interface. Unfortunately, the majority of people are exposed to this slow moving face. Presumably this face is slow moving and not automated because the demand for speed is low. I think it’s really sad that people don’t see the potential to automate the really mundane parts of banking away.

I share a rented house with others. I do the house “accounts”. There’s a spreadsheet (don’t get me started on spreadsheets… that’s a rant for another time) that I carefully maintain that annotates each transaction that occurs in the house bank account with things like who is responsible for them. The spreadsheet divides bills between people in the house.

I tend to put more money into the house account than is needed because the manual transfer and annotation of data between my bank’s website and the spreadsheet is extremely boring. The insulation that this extra money gives allows me to spend less time doing it. If my bank provided some sort of API that’d allow me to extract useful information about my accounts, then this work would be much less tiresome. Another application of bank automation is paying rent every 3 months. I don’t think any of the banks that I have accounts with allow me to set up standing orders with arbitrary periods — they seem to assume that everyone wants to pay monthly. Again, an API would allow me to script my transfers and set up more “advanced” standing orders.

I have accounts with several banks. Filing all the paperwork they send me is a boring chore. Then there’s all the forms that need completing to transfer money between ISAs. Misery!

In his “How To Become A Hacker” document, Eric Raymond writes:

Hackers (and creative people in general) should never be bored or have to drudge at stupid repetitive work, because when this happens it means they aren’t doing what only they can do — solve new problems. This wastefulness hurts everybody. Therefore boredom and drudgery are not just unpleasant but actually evil.

To behave like a hacker, you have to believe this enough to want to automate away the boring bits as much as possible, not just for yourself but for everybody else (especially other hackers).

Are banks moving in the right direction for their clients to automate interaction with them? No. They’re distributing devices that require people to be present when they do things related to their bank. We can only hope that one day enough of their customers understand that scripting their banking is the way forwards. I severely doubt this will happen within the next 20 years.

Whilst on the topic of banks, has anyone else noticed that the barclaycard’s “contactless payment” scheme looks like one of the most insecure things ever devised!?

Posted at 7:22 pm on Sunday 19th July 2009


Some exceedingly valuable research has recently been done in our kitchen. What follows are some extremely important observations and findings about light bulbs. Pay attention now…

gu10Our kitchen is equipped with a light socket fitting that accepts four “GU10” lights. This is the sort of light fitting installed by someone who likes to spend a lot of time looking at their light fitting, spending money on light bulbs, and changing light bulbs. Perhaps unsurprisingly, I’m not that kind of person. I like my lights to let me look at and spend money on other things.

The bulbs in the kitchen have blown several times over the past year. About 6 months ago, Screwfix offered two types of GU10 lamp: incandescents, and LED-based. The LED lamps claim a rating of 50000 hours. The incandescents claim 1000 hours. At the time, the LED bulbs cost about £10 each — around 5 times as much as the incandescents. It seemed pretty clear which offered the best value for money, so I bought 1 LED bulb as an experiment along with a pack of incandescents.

It turned out the LED based lamp was extremely dim. There was no way of comparing its brightness with that of the incandescents on the Screwfix website or on its box. Our kitchen has since had one single LED bulb that provides an exceptionally dim light.

Then all the incandescents blew. The kitchen was extremely dim. Torches had to be used to verify that meat had been cooked.

So it was back to Screwfix to get some new bulbs. I was overjoyed to find that they now sell compact fluorescent (CFL — also known as “energy saving” light bulbs to some) GU10 bulbs. I bought one (they’re about 4 times as expensive as the incandescents) and was pleasantly surprised to find that it emits a useful amount of light.

Conclusion: Current LED GU10 bulbs from Screwfix don’t emit enough light for lighting a room. The CFLs do.

There you go. Admit it. You didn’t know that light bulbs could be so exciting.

Posted at 3:05 am on Saturday 18th July 2009

Farnell OpenSearch Plugin

Chris and I spent a few hours this afternoon converting the SR board designs over to a new BOM-generation compatible situation. The new system should let us script the generation of the BOMs, gerbers and orders for the next shipment of SR boards.

Whilst we were doing this, Chris gave me the idea of making a Farnell search plugin for Firefox. It turns out that Firefox supports something called OpenSearch. This lets you tell a browser how to use a search engine. You should find my Farnell search plugin embedded in this page. In Firefox, click the drop-down box at the left of the search menu. It’ll give you an option to add this search, as shown in the screenshot on the right.

search-farnell-2 After installation, you should be able to search Farnell. This plugin uses my Farnell permalink URLs to do the searches, so you can type a part number in and will be taken directly to the corresponding part’s page.

Posted at 10:34 pm on Sunday 5th July 2009

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