Robot mounted air cannon

[flameout]

I'll make the assumption that the valve wired up for the launcher can operate on 12 volts (we use sprinkler valves for our launcher -- they seem to work fine).

To set this up, you'll need to create a pneumatics system (you didn't mention any difficulty in mechanical, electronics, or pneumatics, so I'll assume you know what you're doing there), but instead of piping the output of the regulator to Festo solenoids, pipe it into the barrels. Then, attack an additional Spike relay to your bot, and wire the valve to that.

You didn't state what programming language you're using, so the specific implementation may differ, but in general, you'll have to do a few things for this system:
1) Create a Compressor object (obtain a reference if in LabVIEW)
2) Start the compressor (I'm not sure if this is necessary -- my guess is that it is).
3) Create a Relay object (obtain a reference if in LabVIEW)
4) Set the Relay to either output a Forward signal or an Off signal, based upon the state of a joystick button (this could be done with a joystick VI, ternary, and Relay VI in LabVIEW (I'm not sure what they're called exactly)).

Also, a note of warning: do not use PVC for the tanks. PVC is not designed to hold air, and can potentially explode with no warning. If the tanks are PVC, then please replace them with metal ones. You can find more by doing a search for PVC on ChiefDelphi.

I hope this helps.