A couple of months ago I purchased several relay boards and switching power supplies off eBay with the plan to re-use one of my original (256 megs of RAM and no mounting holes) Raspberry Pi model B computers as a sprinkler controller. The parts arrived and I set them aside expecting to have time to work on the project after the 4th of July. About two weeks before the 4th though I realized if I got the project assembled in time I could use the sprinkler controller as a fireworks controller. ...