Your First Raspberry Pi: A Buyer's Guide
If you've taken a look at some of our Raspberry Pi tutorials and have decided you'd like to take the plunge and get involved, knowing exactly what purchase can be somewhat daunting. There are different models and cases to consider, various methods of connectivity and storage options to factor in - not to mention planning what you're going to do with it. It's a lot of work for something that's the size of a deck of cards.
In this guide, I explore the wide number of options there are when it comes to selecting the right Raspberry Pi kit so that you're ready to take on any project.
The Raspberry Pi
Designed as a way of encouraging children to learn some of the aspects of computer science, such as programming, the Raspberry Pi is a tiny, inexpensive computer that is adored by hobbyists everywhere. It's low cost and open design heralds a wide range of uses and, as you'll see from our tutorials, you can use it for almost anything - even as a Moisture Sensor to Monitor Your Plants!
A or B?
Until recently, there was just one model of the Raspberry Pi. Presently, there are now two models: Model A and Model B.
Both models have the following in common:
- 700MHz ARM processor
- RCA and HDMI video-out
- 3.5mm audio jack
- SD Card slot
- CSI input for a camera module
- Micro USB power-in
- Dimensions and weight
These two models operate in the exact same way but there are some hardware differences.
Tip: Despite having an alphabetised model name, A and B doesn't represent the order in which they were released. In fact, Model B was released first (with less RAM) and Model A is the newer, cheaper variant..
The cheaper of the two ($25), the Model A has the following specifications beyond the ones listed above:
- One USB 2.0 port
- 256MB RAM
- 1.5W power rating
It's important to note that the Model A features no onboard networking. This lower hardware specification has the advantage of having extremely low power requirements. A Raspberry Pi requires 30x less power to operate than an 11" MacBook Air.
The latest version of the Raspberry Pi that was originally released, it's a little more expensive at $35, but you do get more for your money:
- Two USB 2.0 ports
- 512MB RAM
- 10/100 Ethernet
- 3.5W power rating
Unlike Model A, Model B does include networking capabilities, making it the preferred option for any networking-related project.
The Best Model For You
For new Raspberry Pi hobbyists, Model B will always be the better option. It has more RAM and an Ethernet port. It's likely that some of your first projects will involve a network connection, whether it's using a Raspberry Pi as a web server or streaming music to it.
Model A is more suitable for projects that have very strict power consumption requirements where every watt counts. Existing Raspberry Pi hobbyists will feel more comfortable with Model A for additional projects that don't require any network connection.
There are a number of ways that your new Raspberry Pi could become damaged, either through physical means or even electrostatic discharge. While the Raspberry Pi is certainly inexpensive, you'll still want some way to protect it.
Cases for the Raspberry Pi have been around for some time now and are not only a really affordable way to protect it, many of them are pretty stylish too. Most of the cases will be designed with Model B in mind but this doesn't mean you cannot use them with Model A as the board itself is the same dimensions.
Your choice of case will mostly be an aesthetic decision and you'll spend most of the time deciding what colour to go for, if any.
Avoid a Warm Raspberry Pi
As the Raspberry Pi is a computer, it generates heat. You'll want to make sure that any case you go for has been designed with that in mind. Some "off-brand" cases are basically just two slabs of plastic with no way for heat to dissipate. Don't forget, there isn't a fan or any substantial heat sink with the Raspberry Pi.
ModMyPi, a popular site that sells all things Raspberry Pi, has a wide selection of cases, most of which cost less than $10. They're also modular, featuring independent top and bottom sections, providing easy access and further customisation so you can mix and match the case colours to create some truly unique colour schemes. Again, all very aesthetic!
Although most of the cases are purely about personal taste, it's worth spending the extra few dollars on a well-reviewed and popular case.
Absolute power corrupts… but not enough power and you'll never get your Raspberry Pi going. Your Raspberry Pi has a small Micro USB port that is used to provide power. Because it's power consumption is so small, it can easily be powered by your computer's USB port or many powered USB hubs just by using a Micro USB cable.
For starting out, this is incredibly useful but once you put your Raspberry Pi to good use and need to use it away from your computer, you're going to need to give it an an alternative source of power.
Micros USB power adapters are extremely common, being found packaged with most smartphone and tablets (with the exception of Apple), so chances are you may already have one spare. To ensure you provide adequate power to the Raspberry Pi (and avoid damaging it), make sure to use a power adapter that is rated for 5V with a current of 1A. Luckily, most generic smartphone chargers also use this.
If you don't already have a power adapter, they're easily sourced from sites such as Amazon and eBay.
Most modern computers have been able to boot from a USB storage device for some time and it's one of the easiest ways to load a Linux installation.
On the Raspberry Pi, it can only boot from an SD card. Whilst there are ways to use an operating system that's stored on a USB stick, the Raspberry Pi has to load boot information, something it can only do from an SD card. Because of this, it's usually easier just to load the SD card with all the files you need.
If you've been using a digital camera for any length of time then you may also have one spare, saving you the need to purchase another.
SD cards have a Class Rating which represents the maximum transfer speed that they can support. They are as follows:
- Class 2: 2MB/s
- Class 4: 4MB/s
- Class 6: 6MB/s
- Class 10: 10MB/s
Due to the relatively slower speed that the Raspberry Pi runs at, it doesn't make much of a difference if you were to go for a Class 10 over a Class 4 so the latter will be cheaper to purchase.
This really does depend on what you intend to use it for. If this is just to get started in tinkering with the Raspberry Pi then an 8GB card would be just fine but if your budget allows, go for a 16GB.
As this is likely your first Raspberry Pi, you're probably going to want to connect it to a display for further configuration.
The Raspberry Pi can be connected to a HDTV or computer display via HDMI, or to most TV and video capture devices via an RCA Composite Video jack.
The Raspberry Pi supports HDMI video, with resolutions up to 1920×1200. HDMI is the best way to output video since it's far more likely that you have a HDMI-equipped display. Many HDTVs will have multiple HDMI ports so you can simply plug your Raspberry Pi into a spare port, allowing you to start your project without the need for a dedicated display.
Most recent computer displays will also include HDMI as standard though some will still only provide a DVI connector as a means for a digital connection. If your display falls into this category, there are many HDMI-to-DVI cables you can purchase that will allow your HDMI-equipped Raspberry Pi to connect to a DVI computer display.
You've probably seen this type of connector on pre-digital video cameras and VHS machines and only supports a maximum resolution of just 640x480. To put that into perspective, the iPhone 5s and iPhone 5c's display resolution is 1136x640.
There's generally no need to use Composite Video unless you have an old TV you want to use as it's is a feature added to ensure that the Raspberry Pi is as widely accessible as possible around the world. There are still many countries where digital displays are not particularly common or are very expensive and Composite Video provides a way for people within those countries to still enjoy the Raspberry Pi.
Keyboard and Mouse
Just like a traditional computer, you'll need a keyboard and mouse to input information into your Raspberry Pi. Since your Raspberry Pi projects may eventually require no input devices once they're configured, it makes sense to either use what you already have or buy as cheap as possible. If you already have a keyboard and mouse that you use with your desktop computer, you could easily use that.
Wired or Wireless
When thinking of a cheap keyboard and mouse, you'd be forgiven for instantly considering a wired keyboard and mouse. Trouble is, especially if you're using your HDTV as a display, all these cables are going to get quite messy. A cheap OEM wireless keyboard and mouse kit can be had for less than $20 these days and will be much easier to use. There's no trail of cables or having to stand right next to your TV just because your keyboard and mouse are plugged in via USB.
Wireless keyboards and mice tend to include a USB receiver that you plug into the USB port. The benefit of going wireless is that a wireless keyboard and mouse will both use the same, singular receiver. You'll only use one of the two USB ports on your Model B and as Model A only includes one USB port, this makes sense also.
Audio output is provided by a 3.5mm jack, compatible with pretty much any set of headphones or speakers. Because of this, it wouldn't make sense to purchase a dedicated set of speakers when you can simply use a set of headphones.
Model B Raspberry Pi's include 10/100 Ethernet to provide network connectivity. This does mean making sure to keep the device near your router or ethernet switch if you intend to use it for any sort of networking project.
This isn't always possible, however, but there are ways to provide some flexibility. Some of this may be overkill for something as cheap as a Raspberry Pi but they are options nonetheless and still worth considering.
Power Line Networking
By no means a new technology, power line networking allows the use of your home's electrical wiring as a way to extend your network. In effect, your home's electrical circuit becomes a one massive network hub.
Power line networking kits cost from around $35 and comprise of two devices you plug into a wall outlet, one near your router that is connected via network cable and one where you'd like to provide network access, connecting it to the device you want to provide network access to, in this case it would be the Raspberry Pi. There's no additional configuration to do and these power line adapters are platform independent and is the same as running a very long network cable from one side of your house to another.
Tip: You're not limited to just two of these and you can add more adapters throughout your home.
This method will allow you to place your Raspberry Pi pretty much anywhere you'd like and it not only makes for easy setup, it means you can place your finished Raspberry Pi project anywhere in the home.
There is no built-in wireless networking but, depending on the flavour of Linux or other operating system you intend to use, you can.
As the number of compatible devices can vary greatly, especially when it depends upon the OS being used, it's impossible to recommend any one device for all uses. Many networking devices aren't unique and will often use the same chipset, the actual circuitry, within. In effect, these USB wireless adapters are basically re-branded for its respective manufacturer.
For the most common Raspberry Pi operating system, Raspian, the most popular device is the Edimax EW-7811Un. This uses the Ralink 5370 chipset so, technically, any device that uses the same chipset will work. Edimax's offering costs less than $10 from Amazon and requires very little in the way of configuration.
For something so small, it can be quite daunting to know exactly what you might need. I've created an Amazon.com Wish List for you to base your search from. All of the items aren't required and you may find cheaper items on sale or with prices that have since changed.
Here's the list in full (prices rounded to nearest $1):
- Raspberry Pi Model B $43
- CY Raspberry Pi Case in White $10
- AmazonBasics USB Adapter $9
- AmazonBasics Micro USB cable $5
- AmazonBasics HDMI Cable $5
- Inland Pro Wireless Keyboard and Mouse $16
- Kingston 8GB Class 4 SD Card $6
- Edimax EW-7811Un Wireless Adapter $10
- TP-Link 200Mbps Power line Adapters $35
Total cost without networking: $94.
For the purposes of the wish list, I did include the Raspberry Pi though it's available for its stated price of $35 at various resellers that can be found via the official Raspberry Pi website. The listing currently on Amazon is through a 3rd-party and has a slightly inflated price. It isn't much of a difference (less than $10) and is likely to arrive quicker through Amazon, though the choice is yours.
Some of the above can be removed if you already have the necessary parts of the kit available. For example, you may already have a USB power adapter, Micro USB cable or HDMI cable, in which case you can remove them from the build.
While it can be difficult to know exactly where to start, spending time getting as much of your kit planned as possible will prevent the frustration of receiving all of your kit, only to find out you're missing just one cable that you forgot.
I hope that any budding Raspberry Pi hobbyists reading this will be able to have a much better understanding of what is needed and we'd love to hear what you've been able to do with your Raspberry Pi in the comments.