Well I'm just learning how to make redstone machines, and I was wondering if I could make a machine in which when someone (or something) stepped on a plate it opened the door, but I could have a lever the was the override switch to make it so that plate didn't work anymore. So the final question is, if you can make it, how do I?
Definitely possible. All you need is a simple AND gate.
Let's say you have:
Pressure Plate (P) - State 'on', 'off'
Lever (L) - State 'on', 'off' - With 'off' being the over-ride. i.e. when L is 'on' the pressure plate works.
Now all you have to do is this:
Note: You can do A OR B (the diagram). They're both AND gates.
With one input being the (P) state and the other being the (L) state. Hope you got that?
Let's say you have:
Pressure Plate (P) - State 'on', 'off'
Lever (L) - State 'on', 'off' - With 'off' being the over-ride. i.e. when L is 'on' the pressure plate works.
Now all you have to do is this:
Note: You can do A OR B (the diagram). They're both AND gates.
With one input being the (P) state and the other being the (L) state. Hope you got that?
Link to the wiki page to understand what each block means: http://www.minecraftwiki.net/wiki/Redstone_circuits
Made by Me
This really helps, but now I'm wondering if there was a way that the lever opened the door, but when it was off it kept the door from being opened.