If you’re here reading this, you either a) are an absolute beginner in making things with redstone and you want to learn how or you just felt like clicking on the thread. I’m here to help out the person in case A, so the concepts in this guide will start off with the most basic topics regarding redstone. If you feel like any or all of this guide is “common sense” or “easy”, then you don’t have to read it. I’m not forcing you to read it, and I’m for sure not forcing you to comment on it. So if you’ve got any straight negativity to bring to the table, I ask you to find another table and bring your negativity there. If, on the other hand, you have some constructive criticism to bring to the table then, by all means, please do.
Table of Contents
- [*:3usqo0so]The Basics of Redstone
[*:3usqo0so]How Signals are Transmitted
[*:3usqo0so]Other Guides and Topics
The Basics of Redstone
The most basic assumption I will make in this guide will be that you have found redstone and you are now trying to do something with it, but you haven’t yet figured it out. Redstone- as you may have noticed while mining it- can be in one of two states at any given time- powered or unpowered. When you come across a block of redstone in a mine or cave, it is initially in an unpowered state. If you happen to click on the redstone ore, you’ll notice that it lights up and starts emitting some red particles. This is the powered state of redstone. In comparison to binary, the unpowered state is off, or 0, and the powered state is on, or 1.
Once you’ve mined some redstone, you will have a various amount of redstone dust. Taking the redstone in hand, you’ll notice that when you place it on the ground, the very first piece forms a redstone cross on top of the block that it was placed on. Placing any redstone north/east/south/west of it will cause the redstone to form a line in that direction. You’ll also notice that when you first place redstone, it will be in its unpowered state (dark red).
Now that we’ve made some basic observations, how do we go about doing something with it? Logically, you must apply some type of power source to the redstone line you’ve placed. The most basic power source is a redstone torch, which is crafted with a stick and a piece of redstone dust. If you place a redstone torch by itself, notice that the default state is powered. If you place this at one end of your line, you’ll see that the line immediately turns “on” to its powered state (brighter red, emitting particles). You’ve now got your first live wire! But what do you do with it?...
How Signals Are Transmitted… An Important Concept!
Now that you know the most basic way to power a redstone line, what can you do with it? Before you can start doing things with redstone, you’ll need to know in what ways a signal is transmitted.
Start by following my example. Find a nice flat area and lay out a line of redstone- oh, say.. 5 blocks long. Again, notice that the line is unpowered. Now, place a redstone torch at one end and the line will become powered. You can think of this torch as now being a “source block” of power to the line.
For the sake of learning, place another redstone torch at the other end of the line. What happened? Nothing. This is because you’ve just placed two “source blocks” of power on the same line. They’re both powering the line, so the line continues to stay on. Nothing special there..
Now, destroy one of the torches. Place a block down where the torch used to be at the end of the line. On top of this block, place a redstone torch.. what happened? The torch switched to an unpowered state. This is an important concept; whenever a torch is receiving power, it will be unpowered. Also a very important concept to understanding redstone is that a redstone torch receives power from a line when it is mounted on a block that is at the same height as the source line. This may be easier to explain in pictures, so here we go!
As you can see in the first picture, torches placed on the ground at the same height as and adjacent to the line (wire) act as power sources. In order to turn a torch off, you must supply it with power. This is done by placing a block at the same height as the redstone wire and mounting the torch on one of the four sides as depicted in the second picture above. You may notice that I left out a torch facing the powered wire. Why is that? Because then you’ve simply got two source blocks powering the same wire. This is important to understand. When redstone wire comes into contact with a vertical face of a block, that face of the block then becomes an input. You can have anywhere from 1 to 5 inputs coming into a block (really you can have 6 but then there would be no output). Any face of the block that has a torch mounted on it therefore becomes an output for that block. In a block with 1 input and 1 output, the output will always be opposite of the input. That is, if the input is powered, the output will be unpowered and vice versa. This type of block is known as an INVERTER, and is the simplest logic gate we can make. We'll learn more about logic gates below.
Whew, that was a lot of concept for one paragraph.. and a lot of text. Let’s break it up with a picture!
In the top-left, you can see that a vertically-mounted torch will power any adjacent wires. The block directly beneath the torch was left out purposely, to show that that particular block is not needed. This is important when you get around to optimizing gate size and efficiency, as you'll be able to sneak some wire where that block would have been.
In the bottom-left, you can see a torch powering a wire directly beneath itself. This is good for short-distance vertical transmission when you need it. For compact, long-distance vertical transmission, you'll want to use the set-up in the top-left (above paragraph).
On the right is one that will mess you up if you're not aware of it, because it's not immediately obvious how it works. When a block is placed above a torch, that block receives power from that torch when the torch is ON. This block will then power any redstone wire adjacent to it. This is similar to a concept that we're already familiar with- buttons, levers, and pressure plates. All of these forms of inputs power the block they are on, which in turn will power any wire adjacent to it. The only difference between those mechanisms and this example is that the torch is powering a block above it- something the mechanisms can't do.
A nuance to watch out for as a beginner is how you approach your inputs. Input wires must be coming straight into the face of the block. This means that you cannot run a wire north/south and have it connect to an output that is 1 block to the east or west of the wire (fittingly, you can't run it east/west and have it connect to an output 1 block north or south, either). Instead, move the output block one block farther away and lead the wire into the input of the block. To make sure everything connects as it should, ensure that all inputs finish with a straight piece of redstone (not a corner piece).
The wire on the left is a no-no because the wire leading into the input is a corner piece. The wire on the right is a yes-yes because it turns the corner and leads a straight piece of wire into the input. However, the same does not hold true for output. The first piece of wire leading out of an output can be either straight or a corner piece (or any formation of redstone, for that matter).
This does not hold true for outputs that are being powered by redstone on top of its block. Redstone wire can be in any formation if placed on top of a block whose outputs are on its vertical faces. Here is an example:
Please, before you move on, make sure that you understand the concepts we've already covered. Without a solid understanding of how signals get transmitted and how to ensure you've got proper inputs, you will struggle once you start making more complex circuitry. Go in-game, make some of the improper inputs and then fix them. The best way to learn is by doing it yourself. Make sure you understand how signals are transmitted, especially vertical transmission, as these can help you when you understand them and hurt you when you don't.
What do you think the contraption in the second picture does? If you don’t know what it does, test it out. What is the state of the output torch when neither input is powered? When both are powered? When only one is powered? Go ahead and test those three cases and try to figure it out. Still not sure? The output will be toggled (switched from powered to unpowered) when either or both of the inputs are powered. This is called a NOR gate. The output of a NOR gate is TRUE if and only if both inputs are OFF. If any of the inputs are turned ON, the output becomes FALSE (or, OFF). Aside from the INVERTER that we learned about previously, this is one of the simplest logic gates you can make. A logic gate is any combination of blocks, torches, and redstone that takes an input (or inputs) and creates an output.
Now we’re starting to learn how to make some logic gates. We’ve got a simple INVERTER and a NOR gate under our belts. What about an AND gate? An AND gate is only TRUE when all inputs are powered. Start with your output block. Place a torch on top of this- this will be your output. Run redstone wire from any two sides of the block- these are your inputs. Now how are we going to get the output to toggle only when both inputs are turned ON? As we’ve demonstrated, the output(s) on a block will toggle when any of the inputs gets turned on. Looking at that occurrence in a different light, this means that the output will stay off as long as at least 1 of the inputs is powered. So what do we want the default state of each input to be? We want the default input state to be powered. Then, when all of the inputs are unpowered, the output will toggle (turn ON in this case).
So we know what we want, but how do we accomplish it? If we were to attach our power sources directly to the wire already replaced, you’ve got a NOR gate (whose default input state is unpowered). How are we going to make it so that when we place a torch as the power source, it unpowers the input? An INVERTER! Go ahead and install an INVERTER on each of the inputs, with the output of the inverter leading to the inputs that we created first. Now you can pick a face of each INVERTER's block to be the inputs and run redstone out of them to where you'll place power sources. You’ve now got an AND gate! Go ahead and try it out. Start with placing one torch. Did it do anything? It shouldn’t have. Place a torch at each input. Did the final output turn ON? Yes! You’ve just created your first logic gate (INVERTER and NOR didn’t count, they’re too simple!)
An AND gate
Go ahead and try to make an OR gate. The output of an OR gate is TRUE (powered) when one or more of the inputs are powered. Think about it, design it, and open the spoiler below to see if your design works the same way as mine.
This picture also demonstrates an important concept: if two or more redstone wires are merged together, the wire will take the higher input at all times. Essentially, combining them acts as an OR gate. When either wire is powered, that whole section of wire will be powered.
So far, we've placed/removed torches as needed to act as input. A torch powered the line, and having no torch left the line unpowered. However, this is not desired. A torch with no input (the torches we've been using as power sources in our examples) is considered a CONSTANT (CONSTANTS are necessary in more advanced circuitry). Basically, we've been placing and removing CONSTANTS each time we needed to change the input, modifying the circuitry each time. Placing and removing torches is akin to opening up your computer and modifying the circuits instead of having a button that does the desired input for you. So, we need something that simulates USER INPUT instead of modifying the actual circuitry every time we need to change the input.
Thankfully, we’ve got just the remedy, and it comes in the form of levers, buttons, and pressure pads. Buttons and pressure pads are used to send a signal for about 1 second before cutting off again. A pressure pad will stay on as long as an object is on it (you, a mob, or an item). This is good for giving power to something that you only need for a few seconds (such as opening a door). Levers stay in whichever state you put them in.
Go ahead and make a few levers before continuing (cobblestone on bottom, stick on top). In each of the gates you’ve made, replace the torches you were using as power sources with these levers. When first placed, the levers are equivalent of not having placed a torch yet. When you toggle the lever, it’s the same thing as placing a torch to power the wire. Much more convenient, right?
Same Difference... or, Gate Construction Variation
Gates can be made in any number of ways. If you really wanted to, you could build everything out of OR gates, or NAND gates, or XOR gates.. so the examples you've seen so far are just some of numerous ways to make gates. Don't fall prey to thinking that the examples depicted in this guide are the end-all-be-all of logic gates. There are many more that I did not detail, and many combinations of them that form more advance circuitry. Experiment with different gates found in the links below to learn more.
What Can I Output To?
Output is not limited to making a torch turn on or off. Although you can do some pretty cool stuff just with torches (screens, timers, flashing decorations, etc), many other things can be powered by redstone as well!
From top to bottom, we have redstone opening doors, switching rail junctions, playing note blocks, and firing dispensers. Note blocks can be used to make anything from simple door bells or audible alarms to full-scale melodies. Dispensers are great for dispatching enemy mobs, since it fires arrows just like you would with a bow and arrow!
As you're learning about redstone, you are undoubtedly going to see a lot of schematics being posted. What are they? A schematic is simply an easy-to-read diagram of a circuit. The easiest way to make, view, and edit schematics is to use a program called Redstone Simulator. However, interpreting these schematics can be a bit daunting at first, so here's a little explanation of the basics:
That should take care of it for the symbols. If you're interested in designing circuits in redstone, you pretty much need to know how to read these diagrams. I suggest getting the program and creating some of the logic gates we've made so far to get a good grasp on the subject. Now you'll be reading schematics with ease!
Latches, Flip Flops, and Clocks
These are essential components to doing anything substantial with redstone. Each have their own uses and are important in their own ways. Read my reply here to learn a little bit about these components (it's at the bottom of the post).
You may have heard of material implication before and not understood exactly what it means. To be honest, I still don't even completely understand how it works, but I've got a decent grasp on the concept. Check out my post here to learn a little bit about material implication (it's in the middle of the post).
More topics to be continued…
I hope that this guide has given you the very basics of redstone such that you can now pick up other guides on the forum (links at the bottom) and roll with what they’re talking about. If you like this guide, please let me know that my guide isn’t going to waste. If you think there’s something to add or you can explain it better, let me know and I’ll be sure to give credit where it’s due. Also, if you have links to more guides, feel free to post them.
Redstone Logic Gates and FAQs Compendium - viewtopic.php?f=3&t=111562
--A topic for everything redstone.
“red stuff” logic gates - viewtopic.php?f=35&t=16440
--A pretty large compendium of logic gates. Not a tutorial. (Archived, contains a lot of outdated information).
Minecraft Wiki: Redstone Circuits - http://www.minecraft...dstone_circuits
--A detailed list of circuits and how they work. Of particular interest is the topic of vertical transmission (at the bottom).
Redstone Simulator - viewtopic.php?t=17924
--A program for designing redstone circuits.
--imapiekindaguy - catching my careless mistake.
--DiEvAl - suggested [img] tags to make things smaller.
--icks - corrected my labeling of a NOR gate as an OR gate. Also clarified my description of inputs and outputs.
--Cadde - suggesting that I change my presentation of power transitions to be more clear ("How Signals Are Transmitted" section),clarifying between CONSTANTS and USER INPUT, detailing the numerous ways gates can be formed.
--CX gamer - credit for inclusion of alternate outputs ("What Can I Output To?" section).
--Laogeodritt - more careless mistakes, some clarifications.