Since you guys seem to like hardware projects, this is an old project we did. Will try to find pictures for other projects too.
Basically, what it does is find ping-pong balls, aim at them and shoot. Aim is controlled using a laser mounted at the nozzle.
We have auto mode, and manual override, where u control the gun manually with some push buttons: Direction, Shoot and reload.
It fires using a pressurized air tank. Automated control was done on a SBC running Arch.
The Setup
The project
Take 2
Front Panel, Automatic and Manual Override
The not so fancy electronics boards
The nurf reloader