Most high school students struggle to write a passable essay on Catcher in the Rye, but Blake Hawkins has more than earned his high school diploma—and some spending money on the side—by turning an unused locker into a fully-functional soda can vending machine.

Powered by an Arduino hidden away inside a battery-powered control panel, Hawkins’ vending machine takes advantage of the many school lockers that now go unused as textbooks go digital, and laptops and tablets replace notebooks and binders.

And if you find it hard to believe that a high school student would be capable of designing and building his own vending machine, Hawkins has also created a detailed Instructables tutorial that explains how the locker was upgraded, and all the problems he had to solve during its construction.

The vending machine requires exact change, but it’s completely theft-proof, and even knows when someone is trying to cheat its coin slot. The most impressive part, however, is that Hawkins designed it to be installed without modifying or damaging the locker in any way, including a door that automatically swings shut after each use, and a clever way to route power and wiring without drilling any new holes.

[Instructables via Boing Boing]