The Gadgeteer system is great; there are loads of modules that you can easily use to do a range of interesting things. There’s a ‘but’ coming here, of course, and it is this: there’s no obvious way of connecting things which are not already Gadgeteer modules. For example, suppose you want to put a switch on your fridge door, so that you can trigger a Gadgeteer camera to take a picture of the person who is surreptitiously drinking all your milk. Or maybe you want to connect multiple switches, perhaps to determine the ammunition remaining in your USB missile launcher. The Gadgeteer buttons are not really suited to the task. Even if you can physically fit them where you want them, and you’ve got long enough cables, each module only has one switch on it. There’s a solution to this, and that’s what this post will start to cover – adding your own devices to the Gadgeteer system.