Page last updated at 07:03 GMT, Thursday, 30 July 2009 08:03 UK

Hardware hacking just for a laugh


Ellie Gibson meets the man who feeds cats from his VCR and gets whips when he plays '70s video games with fetish boots.

What do a clock powered by decaying prawns, an experiment with a physicist's bladder, some light bulb conkers and a fetish version of Pong have in common?

The answer is the mad professor who invented them or, as James Larsson would rather be known, "a hardware hacking clown".

Silliness is at the heart of what he does.

"I began five years ago with a prawn sandwich clock and it has got a whole lot sillier since then," he said.

The prawn sandwich clock
Time for a prawn sandwich?

With sensors and an old computer plugged into a Marks and Spencer prawn sandwich, Mr Larsson was able to use its decomposition to track the passing of time.

"It was pretty uneven," he admitted. You wouldn't want to catch a train using it."

Mr Larsson used to invent more serious things, from artificial intelligence projects to computer graphics devices.

But, in his own words it "went horrendously belly-up" so he decided to "shun commercial inventing".

He saw the light, as it were, when he heard of Dorkbot, an organisation of geeks and hobbyists dedicated to playing around with electricity purely for the fun of it.

Desperately dangerous

James Larsson
Mr Larsson is a self-styled hardware hacking clown

"I'm a geek, born and bred. As a kid I would take the back off the TV. When I heard about Dorkbot it felt like it was what I'd been waiting for all my life," he said.

Dorkbot's mission statement is "doing strange things with electricity" and they don't get much stranger than Mr Larsson's projects, which include a 30,000 volt version of the classic fairground game where a player has to pass a hook carefully over a circuit to avoid touching it.

In Mr Larsson's version the traditional buzzer is replaced with a huge blue spark.

"I always thought the original steady hand game was rather boring so I decided to give it a makeover. It allows you to do some interesting electrical things such as set fire to things or melt them," he said.

In another nod to old-fashioned games, Mr Larsson has come up with incandescent conkers, which also provides a way to recycle old-style light bulbs which are in the process of being phased out in favour of low-energy alternatives.

In Mr Larsson's version of conkers, two light bulbs are connected electrically with small microphones on each to pick up the sound of impact.

"If they are part-worn some filaments are going to be stronger than others and with 1100 volts being passed through them there is going to be an almighty flash," he said.

"It is surprisingly satisfying to play but desperately dangerous. As well as the risk of being hit with hot broken glass, there is the danger of electrocution," he said.

VCR catfood

Incandescent conkers
Conkers takes on a whole new danger level when you use lightbulbs

While some of the other hobbyists on the Dorkbot circuit derive pleasure from showing off their hi-tech inventions, Mr Larsson is happier with a more low-tech approach.

"If one wanted to imagine what is going on inside a graphics chip it would be mind-bogglingly complex and you can't really visualise it. With a current there is a spark which is visible and obvious," he said.

Perhaps one of his most practical inventions is a VCR cat feeder. As a fan of the old-fashioned video recorder Mr Larsson was determined to find a way to breathe new life into them.

Taking out the motor and attaching it to a meat grinder that dispenses fresh cat food might not be the most obvious way to go about it but in many ways it isn't far removed from the original use.

The timer, instead of recording your favourite TV show, is used to feed your cat "at the time you set", explained Mr Larsson

His latest project is also inspired by cats.

Mr Larsson described his Schrodinger's bladder experiment as a "scatological version" of the famous thought experiment, which uses a cat in a box with poison to illustrate one of the problems of quantum physics.

In this case, the experiment will consist of "a wooden box containing a Geiger counter, a pump containing yellow liquid and whatever radioactive substance I can get my hands on."

The original experiment attempted to show how nothing is real until it is measured, but Mr Larsson's version will have a more jokey endgame.

"In my case Mr Schrodinger has different bladder issues depending on the decay of a a radioactive particle," he said.

He expects it to produce some degree of merriment at the Christmas meeting of Dorkbot, held monthly at Limehouse town hall.

Meanwhile he has a day job, as the designer of water control systems for municipal fountains, to maintain.

It is unlikely he will try to combine his two interests any time soon but it is clear where his real devotion lies.

"When you are out in your shed and the whole history of physics is there for you, there is a lot of personal satisfaction," he said.


Ellie Gibson samples a symphony from the sparking music machine at Dorkbot in June 2009.

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