What is Breadboard?

What Is A Breadboard?

 A breadboard is a rectangular plastic board with a bunch of tiny holes in it. These holes let you easily insert electronic components to prototype (meaning to build and test an early version of) an electronic circuit, like this one with a battery, switch, resistor, and an LED (light-emitting diode).

The connections are not permanent, so it is easy to remove a component if you make a mistake, or just start over and do a new project. This makes breadboards great for beginners who are new to electronics. You can use breadboards to make all sorts of fun electronics projects, from different types of robots or an electronic drum set, to an electronic rain detector to help conserve water in a garden, just to name a few.

Where does the name "breadboard" come from?

You might be wondering what any of this has to do with bread. The term breadboard comes from the early days of electronics, when people would literally drive nails or screws into wooden boards on which they cut bread in order to connect their circuits. Luckily, since you probably do not want to ruin all your cutting boards for the sake of an electronics project, today there are better options.

Are there different kinds of breadboards?

Modern breadboards are made from plastic, and come in all shapes, sizes, and even different colors. While larger and smaller sizes are available, the most common sizes you will probably see are "full-size," "half-size," and "mini" breadboards. Most breadboards also come with tabs and notches on the sides that allow you to snap multiple boards together. However, a single half-sized breadboard is sufficient for many beginner-level projects.

What is a "solderless" breadboard?

Technically, these breadboards are called solderless breadboards because they do not require soldering to make connections. Soldering (pronounced SAW-der-ing) is a method where electronic components are joined together by melting a special type of metal called solder. Electronic components can be soldered directly together, but more commonly they are soldered onto printed circuit boards (PCBs). PCBs are what you will see if you take the cover off many electronic devices, like a computer or cell phone. Frequently, engineers will use solderless breadboards to prototype and test a circuit before building the final, permanent design on a PCB. This image shows the same circuit (battery, switch, resistor, and LED) built three different ways: on a solderless breadboard (left), with the components soldered directly together (middle), and on a printed circuit board (right):

Soldering is a great technique to learn if you are interested in electronics, but the connections are much more permanent and it requires purchasing some tools to get started. The rest of this experiment will focus on solderless breadboards

Which electronic parts are compatible with breadboards?

So, how do electronic components fit into a breadboard? Many electronic components have long metal legs called leads (pronounced "leeds"). Sometimes, shorter metal legs are referred to as pins instead. Almost all components with leads will work with a breadboard

Breadboards are designed so you can push these leads into the holes. They will be held in place snugly enough that they will not fall out (even if you turn the breadboard upside-down), but lightly enough that you can easily pull on them to remove them.

Do I need any tools to use a breadboard?

You do not need any special tools to use a solderless breadboard. However, many electronic components are very tiny, and you may find them difficult to handle. A pair of miniature needle nose pliers or tweezers may make it easier to pick up small components.

 

What is inside a breadboard?

The leads can fit into the breadboard because the inside of a breadboard is made up of rows of tiny metal clips. This is what the clips look like when they are removed from a breadboard.

When you press a component's lead into a breadboard hole, one of these clips grabs onto it.

Some breadboards are actually made of transparent plastic, so you can see the clips inside.

Most breadboards have a backing layer that prevents the metal clips from falling out. The backing is typically a layer of sticky, double-sided tape covered by a protective layer of paper. If you want to permanently "stick" the breadboard to something (for example, a robot), you just need to peel off the paper layer to expose the sticky tape underneath. In this picture, the breadboard on the right has had its backing removed completely (so you can see all the metal clips). The breadboard on the left still has its sticky backing, with one corner of the paper layer peeled up.

What do the letters and numbers on a breadboard mean?

Most breadboards have some numbers, letters, and plus and minus signs written on them. What does all that mean? While their exact appearance might vary from breadboard to breadboard, the general purpose is always the same. These labels help you locate certain holes on the breadboard so you can follow directions when building a circuit. If you have ever used a spreadsheet program like Microsoft Excel® or Google Sheets™, the concept is exactly the same. Row numbers and column letters help you identify individual holes in the breadboard, just like cells in a spreadsheet. For example, all of the highlighted holes are in "column C."

All of the highlighted holes are in "row 12." "Hole C12" is where column C intersects row 12.

What do the colored lines and plus and minus signs mean?

What about the long strips on the side of the breadboard, highlighted in yellow here?

These strips are typically marked by red and blue (or red and black) lines, with plus (+) and minus (-) signs, respectively. They are called the buses, also referred to as rails, and are typically used to supply electrical power to your circuit when you connect them to a battery pack or other external power supply. You may hear the buses referred to by different names; for example, power bus, positive bus, and voltage bus all refer to the one next to the red line with the plus (+) sign. Similarly, negative bus and ground bus both refer to one next to the blue (or black) line with the minus (-) sign. Sound confusing? Use this table to help you remember—there are different ways to refer to the buses, but they all mean the same thing. Do not worry if you see them referred to by different names in different places. Sometimes you might hear "power buses" (or rails) used to refer to both of the buses (or rails) together, not just the positive one.

Note that there is no physical difference between the positive and negative buses, and using them is not a requirement. The labels just make it easier to organize your circuit, similar to color-coding your wires.

How are the holes connected?

Remember that the inside of the breadboard is made up of sets of five metal clips. This means that each set of five holes forming a half-row (columns A–E or columns F–J) is electrically connected. For example, that means hole A1 is electrically connected to holes B1, C1, D1, and E1. It is not connected to hole A2, because that hole is in a different row, with a separate set of metal clips. It is also not connected to holes F1, G1, H1, I1, or J1, because they are on the other "half" of the breadboard—the clips are not connected across the gap in the middle. Unlike all the main breadboard rows, which are connected in sets of five holes, the buses typically run the entire length of the breadboard (but there are some exceptions). This image shows which holes are electrically connected in a typical half-sized breadboard, highlighted in yellow lines.

Buses on opposite sides of the breadboard are not connected to each other. Typically, to make power and ground available on both sides of the breadboard, you would connect the buses with jumper wires, like this. Make sure to connect positive to positive and negative to negative.

Are all breadboards labeled the same way?

Note that exact configurations might vary from breadboard to breadboard. For example, some breadboards have the labels printed in "landscape" orientation instead of "portrait" orientation. Some breadboards have the buses broken in half along the length of the breadboard (useful if you need to supply your circuit with two different voltage levels). Most "mini" breadboards do not have buses or labels printed on them at all.

There may be small differences in how the buses are labeled from breadboard to breadboard. Some breadboards only have the colored lines and no plus (+) or minus (-) signs. Some breadboards have the positive buses on the left and the negative buses on the right, and on other breadboards, this is reversed. Regardless of how they are labeled and the left⁄right positions, the function of the buses remains the same.

What are jumper wires and what kind should I use?

Jumper wires are wires that are used to make connections on a breadboard. They have stiff ends that are easy to push into the breadboard holes. There are several different options available when purchasing jumper wires.

Flexible jumper wires are made of a flexible wire with a rigid pin attached to both ends. These wires usually come in packs of varying colors. This makes it easy to color-code your circuit .While these wires are easy to use for beginner circuits, they can get very messy for more complicated circuits; because they are so long, you will wind up with a tangled nest of wires that are hard to trace (sometimes called a "rat's nest" or "spaghetti").

Jumper wire kits are packs of pre-cut lengths of wire that have their ends bent down 90 degrees, so they are ready to put into a breadboard. The kits are available in larger and smaller sizes.

These kits are very convenient because they come with wires of many different pre-cut lengths. The disadvantage is that there is typically only one length of each color. This can make it difficult to color-code your circuit (for example, you might want a long black wire, but your kit might only have short black wires). Your circuit will still work just fine, but color-coding can help you stay more organized (again, see the section on color-coding for more information). Notice how this circuit looks much less messy than the previous one, since the wires are shorter.

Finally, you can also buy spools of solid-core hookup wire and a pair of wire strippers and cut your own jumper wires. This is the best long-term option if you plan on doing lots of electronics projects, because you can cut wires to the exact length you need, and pick which colors you want. It is also much more cost-effective per length of wire. Buying a kit of six different colors is a good place to start. It is important to buy solid core wire (which is made from a single, solid piece of metal) and not stranded wire (which is made from multiple, smaller strands of wire, like a rope). Stranded wire is much more flexible, so it is very hard to push into a breadboard's holes. You also need to purchase the right wire gauge, which is a way of measuring wire diameter. 22 AWG (American Wire Gauge) is the most common gauge used for breadboards