What is a breadboard and how to use it
If you want to make an electronics project, you will need something to connect your circuit on. Sure, you could solder everything together, but what if you’re just testing something? Or if the project you’re working on is temporary, and you plan on using the parts for something else? You would then use a breadboard.
If you’ve got a starter kit for an Arduino or Raspberry Pi, you probably have one. And you’ll be using it quite a lot. Let’s take a deeper look at what they actually are.
Introduction
A breadboard is a construction base for electronics prototyping. It might look like a regular plastic board with many tiny holes in it, but it’s much more than that. It is one of the main tools for circuit building and electronics in general. Prior to today’s breadboard being invented in 1971, a technique called wire-wrap was used for circuit building. It involved wrapping wires several times around a component lead or a socket pin on an insulating board. You had to be really careful and know what you were doing. Things could get messy quite quickly, as you can see from the picture below.
Solderless breadboard
A solderless breadboard is as simple a device as it gets. It’s the most used device when creating temporary circuits. It is called solderless because no soldering is required, you can just plug in the components. A component can easily be removed from a breadboard if you make a mistake, or when starting a new project. This makes it great for both beginners who are just starting to learn about electronics and seasoned professionals.
If you’ve never worked with it before, you might wonder which holes do what. Let’s take a look at the bottom of a breadboard so you get a better idea of what’s going on.
Bottom of a breadboard
Seeing it like this, you’ll get a better picture of how it works. The smaller metal platings are used for connecting components into your circuit. Rows are not interconnected. Two larger metal platings, perpendicular to smaller ones, are used to connect the board to a power source. That’s why they are referred to as power strips or rails (sometimes called bus strips).
If you were to take the metal platings out, you would see that they are actually little metal clips. They’re designed to grab the legs of components pushed through holes on the top side of the breadboard. Because they’re made from a conductive metal, you can test circuits without any soldering. Hence, the name solderless. All breadboards operate like this, no matter the size.
Top of a breadboard
Looking at the breadboard from the top side, you’ll see a bunch of little holes. This is where the legs of components go, and the clips inside grab on them. The spacing between these holes is 2.54 mm (0.1 inches). It is aligned with the spacing between the legs of most electronic components and integrated circuits.
The holes are divided into two areas called strips. These strips are made from interconnected electrical terminals.
Power rails or bus strips
Power strips (bus strips) are on the sides of the breadboard. They are used to provide electric power to the electronic components. They usually contain two columns – one for ground and one to supply voltage. The row indicating ground is normally marked blue or black, while the row indicating voltage supply is marked red. Along with colors, a ground column is indicated with a minus (-), and a voltage column is indicated with a plus (+).
Power rails generally go from one end of the breadboard to another. The holes are set in groups of fives. On large breadboards, however, the power rails are often broken in two.
Terminal strips
The main areas, those between the power rails, are used to hold most of the electronic components. As power rails, terminal strips are also divided into two columns, with a small ravine between them.
The rows are marked with numbers from 1 to as many as the breadboard design has. The columns are marked with A, B, C, D, E on one side of the board, and F, G, H, I, and J on the other side. Only five components can be connected in each row.
Wait, the row has ten holes, so why can you connect only five components? Notice that each horizontal row is separated by a ravine, or crevasse, in the middle of the breadboard. This ravine isolates both sides of a given row from one another, and they are not electrically connected. Thus, a hole on one side is not electrically connected to a hole on the other side.
Take a look at the picture below. You’ll get a clear idea of which hole connects to which.
Mind the gap
At the very center of the breadboard lies a small ravine. It serves an important purpose. It is 7.6 mm (0.3 inches) wide and enables the usage of integrated circuits.
Many integrated circuits (aka ICs or chips) are developed to fit onto breadboards. Since they tend to be larger than other components, they come in the so-called dual in-line package (DIP or DIL). That minimizes the amount of space they take on the breadboard. The ICs fit perfectly over the ravine. One side of the legs connects to column E, and the other side connects to column F. This way the legs of the ICs don’t interfere with each other’s functionality.
Shapes, sizes, colors…
Breadboards come in all shapes and sizes, but they are pretty much all the same. They are made from plastic and come in different colors, but they are usually in some tint of white. The most common sizes you’ll see are so-called full-size, half-size, and mini. Most breadboards have tabs and notches so you can snap more of them together. For the most part, though, you’ll be fine using just one half-size board included in most starter kits.
Speaking of sizes, while the half-size board will be sufficient for most of your needs, you might consider getting a different-sized breadboard. A full-size breadboard is 17 cm tall and 5.5 cm wide (7” x 2.2”). It has 830 tie-points (holes), or 63 rows and 10 columns. Pulling out the power rails narrows the breadboard to just 3.5 cm (1.4”). It usually has tabs and notches so you can make it longer and wider.
The most common size among beginners is the so-called half-size. It is 8.5 cm tall and 5.5 cm wide (3.4” x 2.2”). As you can see, it’s basically the full-size breadboard cut in half. It has 400 tie-points, or 30 rows and 10 columns. It has removable power rails. Removing them makes the board 3.5 cm (1.4”) wide.
Last but not least, a mini breadboard is 4.6 cm tall and 3.6 cm wide (1.8” x 1.4”). It has 170 tie-points and doesn’t come with the power strip. It’s perfect for small and simple projects. It fits nicely on top of the Arduino proto shield as a small circuit. It is then used as a signal source feeding other electronic circuits. Mini breadboards come in various bright colors, but they are the same no matter the color.
How to connect components on a breadboard
Now that we have an understanding of what a breadboard is, it’s time to learn how to use it. You’ll be able to put most components on the board.
Components have long metal legs called leads used to get the electrical current to the component. Just put these legs through the holes and that’s it! The metal clips below will grab onto them and make them electrically connected to anything else in that row.
Make sure to push them all way through, until they can’t go any further. A lot of beginners will push the legs partially into the breadboard, not wanting to break them. This can, in turn, lead to strange circuit behavior, like LEDs flickering or not working at all, etc. The components can get damaged this way, so it’s always better to firmly push them down all the way.
Keep in mind that some components have very long legs that don’t fit into the breadboard all the way. LEDs are like that. Be careful not to break them when putting them in. You’ll feel it when the component hits the bottom of the breadboard. The connections are not permanent and it’s easy to remove any components that might be connected wrongly.
Jumper wires
To connect the components to each other, Arduino or a power source, we’ll need some wires. Jumper wires are a type of wires that are used with the breadboard. There are two types most commonly used: Dupont-style and U-shaped.
Dupont-style wires come in three varieties, depending on their ends: male/male, male/female, and female/female. They are very flexible and easy to work with, which is why they are often included in starting kits. For connecting an Arduino with a breadboard, a male/male Dupont-style jumper wire is used.
U-shaped wires are simply wires with insulation stripped at both ends and bent at a 90-degree angle. Unlike Dupont-style, these wires keep their shape once they are put in position. They are great for connecting to power and ground since they keep the connection as short as possible.
Both types of wires come in different colors, but they don’t mean anything. There are some color-coding disciplines that you can adhere to for consistency, though. For example, you can use red and blue or black for supply voltages and ground. Use a different color for the main signals, and the rest how you see fit. There’s a common issue with this, though. The number of colors is often smaller than the number of signal types or paths.
Pros & cons of using a breadboard
As with any other product, there are pros and cons to using a breadboard. Let’s take a look at why you would consider using it, and why not.
Pros:
- inexpensive
- it’s reusable, no soldering is required
- changes to a circuit are simple to make by plugging components in and out
- easy circuit construction
- fast and easy way to get prototypes up and running
- a variety of electronic components can be used
Cons:
- not suitable for long-term connections due to them not being soldered
- limited to operating at relatively low frequencies
- not suitable for high current flow (the current limited to ~2 A with a good quality breadboard)
- depends on high-quality contacts so connections don’t lag
- usually can’t accommodate surface-mount devices or components with grid spacing other than 2.54 mm (0.1”)
- connections have higher impedance than soldered connections
- not suitable for components that rely upon a large ground plane connection
- places limitations on how closely components can be placed
When just looking at the bullet points, it wouldn’t be unjustified to think you shouldn’t use a breadboard. The cons list is longer, after all. But pros outweigh the cons in this situation. The breadboard is just too useful for it not to be used in most cases. Unless you’re making a large project or something that must stay connected at all times, you can stick to using a breadboard for your projects.
Fun fact: the name comes from...
…an actual breadboard! Back in the olden days, amateur makers used to hammer nails or screws on a wooden board. They would then put copper wires on them and solder electronic components to them. Often it was literally a board used to slice bread on.
As it usually is with technology, the breadboard of that time has evolved over the years. While breadboards are now used for all kinds of electronics prototyping, they aren’t made from wood anymore. You no longer have to ruin cutting boards every time you wanted to test something. The name, however, stuck and reminds us daily how far we’ve come in just a few years.
Breadboards are here to stay
SMD components are better in almost every aspect compared to their leaded counterparts. The problem with them, though, is that there is no easy way to directly prototype with them without making a PCB to mount them to. Because of this, many SMDs will continue to be adapted for breadboards. You don’t have to worry about fabricating a PCB every time you want to work with a circuit for the foreseeable future. The breadboards are not going anywhere.
Products used in this tutorial
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