I would like to use a Raspberry Pi to inflate a balloon. To do that I need a pump/compressor that I can control (essentially turn on/off, but psi readings would be great too) with the Pi. In my research, I haven't found a pump that was specifically built to be connected to the Pi. Do you have any recommendations regarding pumps? We're talking about a regularly sized party balloon here. And the pump/compressor should be as small as possible, but still powerful enough to inflate the balloon in under a minute.
I would get a cheap tire inflator (one that lets you set the pressure) that runs from a cigarette lighter. Then I would cut the plug off the power cable, attach it to a 12V relay, and control the relay from the Pi. To avoid needing another power source to run the relay you might want to look for a relay board designed specifically for the Pi (these are widely available from the usual Pi suppliers).