Piston doors are probably one of the most popular redstone contraptions. You can make them small and simple, but you can also expand them so you get enormous piston doors. In this post we’ll cover two easy doors: the 1 by 2 and the 2 by 2 door. See the pictures below, it should be easy to see how to build them.
1 by 2 piston door
As you can probably see, apart from the pistons themselves, it only uses a lever and a redstone torch. The redstone torch is there to ‘invert’ the lever’s redstone signal: if the lever is off, it doesn’t power the redstone torch, so the redstone torch is on. If the lever is on, it does power the redstone torch, so it turns off.
When the redstone torch is off, the pistons aren’t activated, so the door opens. When the redstone torch is on, the pistons are activated, so the door closes.
Got it? Great. Now let’s move on to the slightly more difficult piston door: the 2 by 2 door. Again, I’ve taken some screenshots of the door I built:
2 by 2 piston door
As you can see, this one uses pressure plates to open and close. Here’s how it works: when you step on a pressure plate, the redstone below will turn on. This redstone line then powers the two blocks under the redstone torches. As a result of that, the torches will turn off, unpowering the pistons. The door will then open.
Of course, you can place pressure plates at the other side of the door as well, just mirror the pressure plates and the redstone below them.