Introduction to breadboards

 

Introduction to breadboards

So, you want to start experimenting with electronics. Then you really should invest in a breadboard. This is extremely useful for experimenting with electronic circuits. A breadboard allows you to build a prototype circuit that can be quickly changed as the design changes. It also helps when trying to become familiar with a new component.

Breadboards are very simple really, but there are some things to know and perhaps some tips to help you choose the right breadboard and to get the most use out of it.

Let's take a look at a breadboard:

The breadboard above is a single panel with two attached "bus strips." The second picture gives a little more detail. The green lines represent the internal connections of the breadboard. The bus strips on this breadboard are labeled + and - and are used for power. They run the length of the breadboard. Also, notice that the way that they are arranged, the inside edges of each bus strip is opposite polarity. This really helps when working with standard logic and most other ICs, which we will see later on.

The middle area is the component area, and this is where you will work your electronic magic. This area is configured as a series of rows, 65 of them in this case. The rows are split by a channel down the center which is there to allow you to easily remove ICs from the breadboard. The channel is .300" apart, which happens to be the thinnest through-hole IC according to the JEDEC standard. Each half of the component area has 5 columns connected together. Here is a view of the connecting strips, taken of a junk breadboard that I exposed:

 

On some breaboards, the bus strips may be broken at the middle (Usually between row 31 and 33.) This splits your bus strips into 4 separate strips. This is useful if you are working with more than one voltage on your breadboard. If you need only one supply voltage on your circuit, then you should add a jumper across this gap to reconnect the bus strips.

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Types of breadboards

I started off by showing you just a single panel of a breadboard. You can buy breadboards in various shapes and sizes, and they are meant to be able to mount and to join with each other (if from the same series.) A couple of the most common breadboards that people buy are these types:

 

There are even breadboards with built in power supplies and other helpful features! These are great if your space is limited and you don't already have a supply. They can be somewhat expensive, however and usually the power supplies are fairly weak and fixed voltages. Here is one that I have on my computer desk right now:

This particular breadboard is no longer made. It has a +5V fixed supply capable of 1A, and a +- 15V supply. It also has two digital switches and two momentary switches connected to flip-flops. Lastly, it has two LEDs with current limiting resistors. If you are interested in getting a breadboard like this (or maybe something more modern) check eBay or google for "Powered Breadboard" or "Powered Protoboard." There are quite a few out there, but I have not used them before.

Tips for working with breadboards

When working with breadboards, you should always use solid hook-up wire. 22 AWG (or Ga.) works best with breadboards. You should never use stranded wire in a breadboard because the little strands break off and work their way underneath the board where they can cause shorts. This is a pain to troubleshoot, especially when you are working with a new component or circuit and are not 100% sure how it is going to work.

Another type of wire that is useful is CAT5 or Ethernet cable. These are usually 26 AWG solid wire arranged in twisted pair. Just about everyone can find some scraps in just about any IT department. Just rip the insulation and remove the wires. Then cut and strip to your needs. My college gave me about 50 feet of scrap and it lasted me through my whole career there.

If you work with breadboards a lot, you are probably going to get sick of stripping jumper wires all the time. You might want to invest in a different type of jumper wiring that has recently been showing up.

This picture is lifted from the auction of eBay seller Gravitech (http://stores.ebay.com/GravitechEstore) I am not associated with this seller, but have ordered many prototyping supplies from them and have been pleased with their prices and service. Shown above is the Male to Male kit. They also sell Male to Female, and Female to Female. If you got the spare change, you might want to invest in several different sets.

The holes on a breadboard are .100" spacing, which is also perfect for inserting headers, sockets, etc.. on the board. In the picture above, you can see the ribbon cable from a keypad near the bottom. This is plugged into a right angle header which I have inserted into the board. You may want to pick up some .100" single row headers in both straight and right angle. These are useful for creating modules of common circuits which you can plug into your breadboard. You can see a programming adapter for my AVR on my breadboard above. This is using a 6 pin straight header to plug into the board. There are also two dual-row headers for plugging the programmer in. You can make dual-row headers using your single-row headers, however. So, if you are going to buy only one type, make it single row .100" straight headers.

Try making your own "breadboard." As mentioned above, you can purchase different shapes and sizes of just the panels as well as the bus strips by themselves. You will need some type of solid plate to mount them to. But why would you want to do this? Well, you will find that some parts like to be plugged in horizontally and some like to be plugged in vertically. Some circuits are set up and never changed (like a microcontroller with reset circuit, clock, and programming header.) By making your own arrangement of breadboards, you can customize it. Any circuits that never really change should be moved to modules, of course, but more on that later.

Setting everything up

Alright, so you've bought a breadboard, gotten some wire to work with, and placed jumpers across the bus strip gap (if needed.) What else is there to know?

Well, first you need a source of power and second, you need to distribute that power to all the bus strips. You will cut and strip wire jumpers between the bus strips to connect them all together.

For sources of power, you have several options. At the Gravitech store above, you will see some pre-built supplies that are designed to plug into a breadboard and provide several options of input. You can also use a wall adapter either at the correct voltage, or assemble a simple 3 terminal supply on the breadboard and connect the output from this to the bus strips. Next time we will be looking at making some different power supplies. To get you started, check your junk drawer for old cell-phone chargers. These are often 5V @ at least 300mA which makes for a good start. Make sure that after you cut off the connector that you measure the polarity of the two wires. You can then insert these into the binding posts of the breadboard (if present) or make a plug using your .100" straight headers (be sure to mark the positive side!) I wouldn't recommend plugging the wires themselves into the board, since they are going to be stranded wires.

Conclusion

Parts Needed:

  • Prototyping Breadboard or "proto-board"
  • 22 AWG solid wire. Suggest several different colors, especially Red and Black for power
  • wire cutters/strippers
  • A power source (5V DC should be the most useful. At least 300mA)

Hopefully this provided a good introduction to breadboards. Since I am new to 'blogging', I am sure that this entry leaves something to be desired. I will hopefully get better with practice. If there are any questions, feel free to PM me or post below. I would prefer that you post in the blog entry so that others can benefit from your question, but either way would be fine. Your feedback will help me improve.

I will hopefully be posting more throughout the week since this is a pretty big subject. We need to cover the tools, power sources, and some components that you should always have handy for experimenting. We also need to cover connecting things up on the breadboard.

Comments

RetroPlayer's picture

One thing I forgot to mention above:
When connecting power to the pins of an IC or module, I usually just use the solid hookup wire. These connections stay relatively constant, so just connect them up first and leave them. The jumper wires that I use for everything else are very flexible, but they also snake all over the place. The fewer wires sticking up (called "tent wires"), the better. In college, we were expected to route all wires flat on the board with none going over the top of components. And all power wires had to be marked with the correct colored wires. This was for clarity during troubleshooting. Typically, green is used for signal wires, white for clocking wires. Yellow is generally 12V DC and orange is 3.3V DC.

Obviously, your circuit will work regardless of the color of your wires, but if you have access to these colors, it is recommended to follow these standards. It will help out a lot during troubleshooting and design changes.

Golani51's picture

Thanks Retro:

A couple of questions. I am starting to get into electronics with the intention to automate an R/C aircraft, and ultimately to work on a data aquisition system for a UAV.

1. Is there actually much difference between breadboards themselves in terms of quality and so forth? I am starting out but don't want to waste my limited finances with overpriced boards or garbage components. Which model would you sugggest?
2. FFor general work, is it better to simply purchase a pre- mounted board?

Thanks,

Golani

RetroPlayer's picture

Golani51,

1. Not a ton of differences in quality, really. They are all pretty much made the same way. You should be able to find an "insertions rating" for the boards which give you an idea how many times you can plug and unplug wires into it before a socket goes bad. Using thicker wire (most breadboards take 20-29 AWG wire, I recommend 22 awg or smaller) will probably stretch the connectors out more and fail sooner.

As far as recommending one, that's pretty personal, really. It depends on how you are going to use it and what kinds of features that you want. I am in the process of building a custom one right now, but here is one I am using:

 http://www.meerkatsystems.net/html/20-000-019.html

A similar one (and I would have bought this one instead if they had carried it before):

http://www.meerkatsystems.net/html/20-000-021.html

You get four full size boards and having one in the horizontal orientation is very helpful. Here's why:

As you probably can't see too well, The top board is used for all my adapters and such for plugging things into the board. I have an AVR ISP header, JTAG header, USB to serial converter, and a 5V and 3.3V power supply. Having these modules across the top keeps them out of the way. It is also useful if you are plugging in an LCD screen, push buttons, LED displays, etc... The base material is Kydex, which is a very strong thermoplastic which can be heat formed (I just ordered a huge piece for my custom breaboard.) Probably the most important thing to concern yourself with is making sure that you have enough space for everything. The way that a breadboard is laid out, room on it gets taken up very quickly. This is when you start making modules that you can just plug in after you finalize part of a design.

2. I have yet to find a micocontroller dev board that I really liked. Maybe it is because I have been using raw MCUs for so long now. The arduino system looks pretty cool and has lots of "shield" modules for it that you might find useful for your applications. I have yet to use one, but have been tempted to give it a try. Give http://www.sparkfun.com/ a look and see if anything gets your juices flowing.

One final note: There are some breadboards that are specially designed for high frequency work. I am not sure that I see anything in your application that would require it, but it is something to consider when you are looking. I imagine you will probably use an oem GPS module, which will have its own PCB to handle the higher frequencies. I have an older, clunky one that I have used on a normal breadboard and had no issues with it.

Hope that helps.

(Edit: If anyone is curious what that mess on the breadboard is, it is an ATMEGA32 micrcontroller connected to an encoder and a wireless link, and a decoder and LED bar graph on the other side of the wireless link. Just playing around with some new parts to get familiar with them.)

Golani51's picture

Thanks mate. Sold.

Now the difficult work begins!!

Are there any sources of info you find indespensible for beginners (apart from this site of course!!) such as other sites or books, projects, and so forth?

Have you come across any especially good sources (books, websites, etc) for data aquisition system design. I am after a system that would either download remotely (bluetooth for instance) or store onboard data from gyro/accelerometers, pressure taps, cameras, etc.

Thanks for a great site.

Reuven

Osey's picture

I'm new to breadboards - used to build Heathkits decades ago. I would like to design and build a breadboard circuit to control a string of lights (LEDs) to flash in a certain programmable sequence. Can you suggest a good place to start (books, websites etc.)? I would also consider paying someone to do the initial design and educate me on the finer points of breadboard design. Thanks.

pravesh's picture

i am the stdent of B.Tech 2nd in the branch of comptur scince engg.I am use the bread doard in practical and i got knowleg that the how do the work of bread board and its compliceted digram seen.Thanks

shivangi's picture

i want to know how we ca decide which component is in serial connection or parallel connection.
and please suggest me any book for better introduction for breadboard

Serge Daenen's picture

Thank you for a wellwritten intro to breadboards, very useful !
Happy Xmas & 2012 wishes to All ! Serge, Perpignan