Robot wars, powered by Raspberry Pi

It had to happen. A competition purely for Raspberry Pi-controlled robots. In fact it happened last year as well - and the second annual Pi Wars was held in early December.

30 teams from across the UK descended on the Cambridge Computer Laboratory, along with 'show and tell' exhibitors and a host of sponsors, including Rapid. While the Pi Wars challenges were the reason everyone was there, the day was a celebration of the Raspberry Pi in all its forms and the community which is constantly finding new applications and uses for the board that is still less than four years old.

The robots were classified into two separate categories, those with a smaller footprint than A4 and larger than A4 (and smaller than A3), taking part in seven different challenges -

• Proximity alert - stopping the robot as close to a wall as possible
• Line follower
• Three-point turn
• Straight-line speed test
• Pi Noon (mystery challenge)
• Obstacle course 
• Skittles - releasing a ball to knock down skittles

Rather than bouts between robots as viewers of 'Robot Wars' will remember, these challenges tested particular functions of each robot, from proximity sensing to speed and gradient navigation. For example, the obstacle course included a moving turntable with three entrance points which robots had to negotiate their way into and out of, a hump-backed ramp and a ridge of extruded marbles. Several robots met their end on the fiendish turntable of doom!

The obstacle course's turntable

The joker in the pack was the Pi Noon challenge, which remained a mystery until the day of competition, other than organisers saying that robots needed to ‘have the ability to hold a thin wire at one end’. This added a special twist for the robot makers, many of whom had built their creations with the specific challenges in mind. In reality robots were given a balloon to hold, with a pin attached to one end. It was a case of popping your competitor's balloon before they popped yours!

Competitors were also judged on coding, build quality, aesthetics and the contribution they had made promoting themselves and Pi Wars through blogging. At the end of the day the winners were judged in each category. The overall winners in the 'Larger than A4' category, comprising 8 robots, were Brian Corteil's 'Revenge of the Pyrobot' and Ipswich Makerspace's robot, and in the 'Smaller than A4' category (22 robots) KEITH Evolution and Metabot were the leading robots.

Pi Wars was attended by members of the Raspberry Pi Foundation, including Eben Upton, the Foundation's co-founder, software/hardware architect and public face of the Pi. The day was organised by Michael Horne and Tim Richardson and supported by sponsors including Rapid, CPC and Pimoroni.