Page last updated at 11:55 GMT, Friday, 30 October 2009

Tech Know: How to hack a handset

By Ewan Spence


LJ Rich meets the programmers at the mobile phone 'app-athon'

The recipe is simple.

Take as many mobile phone developers, hackers and builders as you can find; put them in The Great Hall at Imperial College; add a liberal helping of heavyweight companies talking about new tools, developer aids and techniques to program mobile phones during the day; then challenge them to come up with "something new".

Leave this to simmer as hackers work through the night and have everyone present their new programs to the rest of the conference the next day.

That sums up the Over the Air hackathon. Now in its second year of bringing together the UK's mobile developer community, it continues to have a huge impact on those who get involved with the overnight competition.

One of the groups involved in the hacking challenge was from mobile developer Future Platforms. Last year it walked away with the Best Overall Prototype for a multi-limbed robot called Octobastard. This year it wanted to produce something beautiful as well as clever. The result was Project Bluebell.

Using the huge number of Bluetooth enabled mobile phones in the room, they put together java code that ran on four basic mobile phones they left in the corners of the Great Hall. Every ten seconds these phones reported to a server the names of other phones in their vicinity that had Bluetooth enabled.

The names of these phones were then used to create ambient music and a visualisation of the music through multiple instances of Conway's Game of Life (a well known set of rules for simulating cell reproduction in graphical form), overlaid on top of each other in varying shades of blue... giving another nod to the blue in Bluebell.

"I was surprised at how well the music side of it worked," said Tom Hume, managing director Future Platforms, after the event. "Generating anything that sounds like music from what is effectively random and varying data was one of the tougher challenges."

It worked so well it won best in show.

One man band

The hacking at Over the Air is also about the individual - while many of the teams organically create themselves on the day, there is still a place for the solitary hacker to turn round something impressive that is two parts evil and one part cute.

A lifelong Lego fan, Adam Cohen-Rose discovered its robotics set at a previous hacking event and ordered one himself.

Robot dalek, BBC
The Lego dalek had a close encounter with the real thing

"I only got the Mindstorm kit the day before Over the Air," he laughed as he walked in with the box under his arm and no idea what to build... until he saw the Dalek in the centre of the room.

"The BBC Dalek only responded when you pressed a button," he noticed, "but with the Lego kit I could build one that controlled its own destiny."

Does his Dalek have any practical use or was this a childlike indulgence?

"I go to events like Over the Air to explore new ideas," he said. "I go to sessions that are relevant though possibly tangential in order to expand my knowledge and understanding of people and technology. I do give myself permission to try out things which are not directly relevant at the moment because you never know what new technology might be around the corner."

And the fate of the Dalek? "It's been taken apart to start teaching my seven-year-old son about robotics."

A cup of Java

Something on the mind of every hacker was coffee, but perhaps it rested more heavily on Sam Machin, who set about the problem of why it takes forever to order a coffee in Starbucks.

As Mr Machin orders the same thing every time, the addition of a RFID chip to his own coffee mug would allow a Barista to simply swipe his cup across a reader and not only read the order, but as the chip/cup pairing would be associated to a pre-paid account, it would also pay for the drink.

"There wasn't really any specific driver for this other than one of my crazy ideas when stood around waiting and thinking how could I make this situation geekier."

Like many hacks at the event, it never quite worked out as planned, especially with physical hacks such as this. Mr Machin used the Arduino PCB to drive the RFID reader in a coaster, but improvisation was the order of the day.

"I powered it all from the USB port on my laptop and there wasn't enough juice to run the controller, ethernet interface, LCD display and RFID reader. I managed to bodge this for the demo with some carefully twisted wires and a phone charger!"

But sometimes Over the Air is a chance to let the hair down.

IPhone music app, BBC
Bottle-Rock-It turned the iPhone into a musical instrument

In 2008 labs put together an interactive sword fighting application on smartphones. This year they were ready to tap into two great cultural phenomena. The iPhone and the rise of rhythm music games such as Rock Band.

Bottle-Rock-It took the Apple iPhone to new orchestral heights. Much like Rock Band you have a moving bar showing where you had to hit your notes. There's no handy guitar attached to the iPhone, but the team put a picture of a bottle on the screen - that was the instrument. Blow into the microphone and just like blowing into a half-full bottle you get a note.

Much like Mr Machin, their project failed to reach their initial vision, in this case an eight-piece orchestra, but a suitably painful rendition of their three note masterpiece was presented to the audience at the end of the event.

The Over the Air hacks demonstrate that ingenuity and creativity is a huge driver behind new technology and ideas, and that this spirit is alive and well in the British developer community. By giving the community permission to play, everyone had a chance to let their hair down and do something fun - while taking away practical skills for the 9-5 life.

As Tom Hume said, everyone involved now has one more challenge: "Only a year to prepare for the next one."

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