Logic Gate Basics Part 2

Just a quick addition to Part 1, before I move on to some more complicated logic gate tutorials.

OR Gate

If any of the inputs are ON, the output is ON, else the output is OFF.

NOR Gate

The direct opposite of the OR Gate, is any of the inputs are ON, the output is also on, else the output is OFF.

Hold for content here.

AND Gate Combo Lock (4 Inputs)

This combo lock only outputs an ON signal when the required combination of ON/OFF inputs are selected. This can be used for houses, banks, traps and even puzzles. 

Click here for a top down plan of this circuit, from the Minecraft Wiki

In this example, the inputs are in the form of 4 levers.

To configure the inputs needed, you simply add or remove torches on the other side of the input blocks (invertors). To use more than 4 inputs, for example 6, add 2 more input levers, and another AND gate at each stage, finishing with a single AND gate.

Logic Gate Basics Part 1

In this series of tutorials I'll be covering the basics of Logic Gates, followed by some practical applications. For reference, in all images, Inputs are shown by Green blocks, and Outputs are shown by Red blocks. By now you should have a basic understanding of the principals behind the behaviour of Redstone. If not, read through the previous Redstone Basics Tutorials.

Invertor (NOT Gate)

Just as seen in a few of my other tutorials, the invertor outputs the opposite of the input, so if the input is ON, the output is OFF.

AND Gate

If both inputs are ON, the output is ON, else the output is OFF.

Triple AND Gate


This works the same as the AND gate but takes 3 inputs, all of which have to be ON for the output to be ON.

NAND Gate

If both inputs are ON, the output is OFF, else the output is ON.

XOR Gate

As long as both inputs have different states, (one OFF, one ON), the output is ON. If both inputs have the same state, the output is OFF.

XNOR Gate

As long as both inputs have the same state, the output is ON. If the inputs have different states, the output is OFF.

Simple Redstone Doorbell Tutorial

Doorbell's are a nice addition to any Minecraft home, and they're a great way to start learning practical Redstone circuits.

First off, place a button 2 blocks to the right of your door, at ground level. Don't place it next to the door as this would cause it to open when you press the bell (unless you want that to happen incase move everything placed in this tutorial one block to the left).

Next, dig a 4x4x2 hole, leaving the block below the button as shown:

Then lay out the following Redstone circuit (double check which way round you have your Redstone Repeater and don't forget the Redstone Wire on top of the block beneath the button.) :

At the end of each wire dig down one more block like so:

Then cover over the holes with Note Blocks, making sure to not to fill the holes:

On to tuning the Note Blocks! Right-click the non-delayed block 16 times, the delayed block 12 times and the Redstone Repeater 3 times (for the longest delay).

Finally, cover over the top layer with dirt, only filling the blocks shown here, so as not to cut off the circuit:

And there you have it, pressing the button now rings your brand new doorbell!

Tutorial: Redstone Clocks

Redstone clocks, are well, exactly that, clocks!

But not as we know them with hands that tell the time, Redstone clocks simply tick, flicking outputs through ON/OFF continuously.

Before the introduction of Redstone Repeaters, clocks were far more complex to make, but with the introduction of Repeaters, clocks are very simple, and easy to adjust between 4 ticking speeds or more!

The basic, 4 speed Redstone clock looks like this:

The Redstone torch on the black wool block will tick constantly, and will tick faster, the lower the setting the repeater is on.

Note that having the Redstone Repeater on the first or second setting will cause the Redstone torch to burn out after a few seconds, so make sure to use the 3rd or 4th setting.

To have a longer time between ticks, just extend the redstone trail, and add another repeater to fill the gap:

So, you've got your clock ticking to the speed you want, but how do you link this to outputs?

It's also very easy, just put add an extra Redstone Wire and connect your outputs:

It's also worth noting at this point that you can connect up to 3 outputs directly to your clock, simple add wires as shown and connect your inputs in place of the green blocks:

That pretty much wraps it up for the basics of clocks, but as you'll see in other tutorials they play a huge part in more complex constructions, such as alarms.

Tutorial 2: More basics

Welcome back to the second part of the basic Redstone tutorials. In the last part you learned about some of the components in Redstone circuits, aswell as the block range of a current, and how to build a simple NOT gate (Aka an Invertor).

In this tutorial, I'll cover the range of inputs you can use, aswell as a second logic gate, the double NOT gate, also known as the Extender.

So to start it off, there's a few ways you can input a signal:

Redstone Torches

As has already been mentioned, these give out power whenever they are unpowered themselves. A Redstone Torch receiving power stops giving it out.

Levers

These have two states, OFF and ON. When flicked, they remain in that state until flicked to the opposite state.

Buttons

These also have two states, OFF and ON, but their default signal is OFF. When pushed, they give out an ON signal for a brief amount of time, before switching off again.

Pressure Pads

Like the two before, these can be either ON or OFF. Their default signal is the same as the button, OFF, and this changes to on when either;

They are stood on by the player or a mob or;

A block or item is dropped onto them.

When they no longer have any weight on them, they return to the default OFF setting.

So there's your inputs, meaning it's time to show you the second basic logic gate, the double NOT gate, aka the Extender.

The Extender is essentially two NOT gates in sequence, but condensed down to save space. This first reverses the incoming signal, then reverses it again, leaving the output the same as the input. Doing this allows you another 15 blocks of current, meaning it's useful when creating long Redstone trails.

In the 3rd basics tutorial I'll cover the variety of outputs you can have in your circuits. Thanks for reading!

Tutorial 1: Basics

Welcome to the first part of our beginners redstone tutorial. In this tutorial, I'll be cover the very basics of redstone creations, and finish off by creating a simple logic gate.

There are 3 main components that are used in redstone circuits:

Redstone wire:

This can have two states, either powered (ON) or unpowered (OFF). Wire is ON when provided with an energy source, such as a redstone torch.

Redstone torches:

When placed at the end of a redstone wire, these provide power, enough for up to 15 blocks of wire.

Redstone repeaters:

Repeaters delay the current passing through them by a maximum of 0.4 seconds, going up in intervals of 0.1, thus to create a 1 second delay, you would need 3 repeaters in a line, 2 set to the 4th interval and one to the 2nd interval.

So with these basics in mind, let's move on to some simple logic gates. These sound more confusing than they really are, as you'll discover.

First off, we have the NOT Gate, also known as the Invertor. Why? Because it inverts the signal coming in, meaning if the incoming signal is ON, the outputted signal will be OFF.

These are easy to build:

"But how do these work?", I can hear you asking. Well it's simple really:

When a Redstone Torch is NOT receiving power, , it stays ON.

When a Redstone Torch IS receiving power from another source, it turns OFF.

So there you have it, the basics of Redstone and a simple invertor gate.

However, the invertor also has a clever little trick: It refreshes the 15 block limit for power, allowing it to travel 15 blocks from the NOT gate.

In the next tutorial I'll be covering different input and output sources, aswell as how to refresh the 15 block limit without inverting the signal.