What is a Breakout Board for Arduino?

If you have been learning about Arduino for any amount of time, than you have probably come across the term Breakout Board. Now, you might think, as I did when I first heard about breakout boards, that they were some fixture for practicing your Kung Fu fighting.

In this lesson, we will discuss what breakout boards are, how they can accelerate your Arduino prototyping and some things to look out for when you buy them.

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Basic Concept of a Breakout Board

The basic concept of a breakout board is that is takes a single electrical component and makes it easy to use.

Usually the electrical component is an integrated circuit (IC). Integrated circuits, as you may know, have pins on them. The pins on an IC can do a multitude of things, but you usually have pins for supply power, pins for providing a ground, pins for receiving an input and pins for sending an output.

A breakout board "breaks out" these pins onto a printed circuit board that has its own pins that are spaced perfectly for a solderless breadboard, giving you easy access to use the integrated circuit.

There are all type of breakout boards - but most of them are for different types of sensors, for example: accelerometers, ultrasonic distance sensors, RFID tag sensors, temperature sensors, pressure sensors, and they even have seismic breakout boards for sensing dinosaurs' footsteps!

Breakout Board vs Arduino Shield: What's the difference?

You might be wondering what the difference is between a breakout board and an Arduino shield, and that is a good question.

Breakout boards usually have a smaller form factor - they don't need the entire space of an Arduino shield to accomplish their mission.

And while the market for most breakout boards is being driven because of their use with Arduino, since the pin-out of a breakout board is not designed specific to the Arduino headers, it means you could use a breakout board with any other microcontroller development board you want - which gives them a bit more scope than Arduino shields.

Also, since breakout boards generally have fewer components than a shield does, you may find the cost is lower than a comparable Arduino shield. As you may have guessed by now, you can find a breakout board that does essentially the same thing as a shield.

You might be wondering, if breakout boards are only a few components, why not just buy the integrated circuit the breakout board uses, put it on a solderless breadboard yourself, and then hook them up to your Arduino?

That is great question, and there is nothing saying you can't – plenty of people do - especially since the components by themselves are often far cheaper to buy alone from an electronics distributor, like digikey or mouser.

So, why the heck are people buying all these breakout boards?

It essentially comes down to convenience. Let me list the ways a breakout board can help you out, and then you make the call:

Breakout boards can save you space

We have already said that breakout boards use integrated circuits. Integrated circuits are kind of like t-shirts - you can get them in all different sizes.

Usually breakout boards utilize a tiny version of an integrated circuit called an SMD (surface mounted device). The pins on SMD parts are really small - not something you can easily pop into a breadboard.

The larger form factor of an integrated circuit, called a DIP (dual inline package) has bigger pins, which fit easily into a breadboard. The DIP package of an IC will be bigger than the SMD form factor.

The point, I am getting to here, is that Breakout boards can sometimes save you space which may or may not be important for your project.

Breakout Boards are designed for reuse

Another thing about using DIP packages is that while the pins are bigger, they are not necessarily sturdy. If you plan to use a DIP component over and over, the usable life of the pins is only so long - the pins on a breakout board however, are heavy duty and designed for reuse.

The DIP version on a component may not be available

One other issue you may find is that the DIP version of an integrated circuit is not available - as electronics get smaller over time, the demand for larger components is drying up and manufacturers are moving away from even bothering with the DIP package, which ultimately brings you back to a breakout board.

Pin labeling on a Breakout board

One great feature of breakout boards is that they usually have the pin names of the integrated circuit labeled on the PCB. This makes hooking up the breakout board to your Arduino a cinch, especially when there are a ton of pins.

Otherwise, you are looking at the black box of an IC and referencing the datasheet of the integrated circuit to try to figure out which pin is for what.

So now that you know some of the benefits of a breakout board, let's talk about a couple things you might want to consider when you are buying them.

Good documentation

I said this about Arduino Shields in the last lesson, but I will say it again - good documentation is like water in the desert. The more you can get your hands on, the better.

Let's face it - a lot of this electronics and programming stuff is not self evident - you need good instructions and reference material to make it work right.

The test I usually use before buying a breakout board is to see what reference material I can find online for it. If nothing tangible exists, you might be spending way more time trying to get it up and running than you would prefer.

Breakout boards are not necessarily interchangeable

As you search for particular breakout boards, you may find that there is a super cheap version available. If you plan on using pre-existing code for a breakout board that references the more expensive version of the breakout board – i.e. maybe in the sketch comments it says, "use XYZ breakout board", one thing you will want to check is that the breakout boards use the same integrated circuit.

If they don't use the same integrated circuit, and you don't know how to adjust the code for these differences, then you may find that the cheap version will cost you more time in trying to figure out how to use it.

Soldering and header pins may be required

Many breakout boards are sold as kits. Usually, the only things you have to solder are the header pins that allow the breakout board PCB to plug into a breadboard - this is really easy to do.

It may also be the case that a kit maker just sells the breakout board with the SMD components, and you have to buy the pin headers separately.

So those are a few things to keep in mind when buying a breakout boards.

Using the correct supply voltage

Finally, once you actually have your breakout board, make sure that you know what voltage supply pin it needs hooked up to.

The Arduino has two voltage out pins, one at 3.3 volts and one at 5 volts. Many breakout boards use a supply voltage around 3.3 volts. Sometimes the supply voltage will be printed right on the PCB by the associated pin, but other times it will just say Vcc, so you will want to check the specs on the breakout board.

If you are just getting started with breakout boards, a great place to look is in the Arduino IDE examples. Some pre-written sketches get you up and running quick with some common breakout boards.

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