Your first RoboCup Junior competition: how to prepare (and what nobody tells you)

The gap between a robot that works in your lab and a robot that scores at a tournament is bigger than any team expects. Here's what actually matters in the weeks before your first RoboCup Junior event.

Before you leave

Test on bad conditions, not good ones. Your lab line is clean and your lighting is constant. The venue's won't be. Tape together course variations with sharp curves, faded lines and direct sunlight if you can get it. If your robot only works on a perfect field, it doesn't work.

Freeze the code. Pick a date, a week before the event is reasonable, after which no new features go in. Only bug fixes. The worst runs we've seen at competitions came from code written the night before.

Practice the restart procedure. After a lack of progress you'll place the robot back at the last checkpoint under time pressure, with shaking hands. Rehearse it: who picks up the robot, who resets the program, how you orient it. Ten seconds saved per restart adds up.

What to pack

Spare motors, spare sensors, spare wheels, anything that has ever broken once. A full toolkit including the weird screwdriver only your chassis uses. Tape, zip ties, hot glue. A power strip (venue outlets are always scarce). Printed copies of your code and documentation for the interview. And chargers for everything, plus charged spare batteries: battery voltage sag changes motor behaviour, so competing on half-charged batteries means competing with a different robot than the one you tuned.

On the day

Walk the arena as soon as you arrive and calibrate on the actual fields during practice slots, every field is slightly different. Watch other teams' runs: you learn more from ten minutes of watching than an hour of last-minute coding. Between runs, resist the urge to rewrite logic. Adjust calibration and speeds, nothing else.

And talk to other teams. RoboCup Junior's best feature isn't the trophy, it's a room full of people who spent months on the same problems you did and solved them differently.