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The Raspberry Pi - Part I: Introduction and Required Hardware
Rather than a microcontroller board, the Raspberry Pi is a complete computer about the size of a playing card. At its core is an ARM11 microprocessor, and it contains HDMI and audio output, 8 GPIO Pins, 2 USB Ports, Ethernet, a dedicated GPU, and more. It’s basically a standalone platform that you can fit in your pocket. The introductory model costs only $25 (the higher end model with more memory runs for $35).
The Pi is capable of running various distributions of Linux, and using it is very straightforward and easy. In fact, the idea behind the Raspberry Pi was to provide a cheap computer platform for schoolchildren to use as an educational tool. It was to be a tool that students with little to no experience using computers could use to learn more about programming, computers, and really any other topic that lends itself well to electronic education. The platform quickly took off however with hobbyists, and it even began to be used in some commercial applications. The device’s low price point, small size, relative power, and ease of use makes it an interesting and flexible development platform.
Because the Raspberry Pi runs Linux, developers who are used to working in a Linux environment can easily get up to speed on the Pi, and they quickly come up with ideas and applications for the device. Many of the popular software packages available for traditional Linux desktops are available on ARM versions of Linux meant for use on the Raspberry Pi, and with the incorporation of a dedicated GPU, multimedia applications that were often limited to desktop environments or specialized embedded platforms are completely viable, and cheap. Finally, the large network of developers provides a good support network for those who are stuck on a problem, or looking for advice — a benefit that some hobbyist platforms and specialized platforms lack.
Even if you’re not a hobbyist, and looking to develop a new embedded solution for a particular problem, the Raspberry Pi can be a good way to prototype a solution without having to go through the entire design and development process. Rather than spending a large amount of money and time into developing a custom built functioning prototype, you can use a Raspberry Pi to greatly reduce initial prototyping costs and get a feel for a potential idea.
If you’re going to do development with a Raspberry Pi, you’re going to need some hardware. Below is a discussion of various pieces of hardware that you’ll need to get started using a Raspberry Pi, and a brief note on its purpose. Most of the parts are easy to acquire at your local electronics store, but the Raspberry Pi vendors listed below will also often sell you this equipment with your Raspberry Pi.
The Raspberry Pi – You can’t have a Raspberry Pi project without a Raspberry Pi. As discussed above, the Raspberry Pi is a playing-card sized computer that starts at $25. You can get these from various locations, but some vendors that are listed on the Raspberry Pi Foundation’s website (www.raspberrypi.org) are:
- Element14 : http://www.newark.com/jsp/search/productdetail.jsp?sku=43W5302&COM=raspi-group
- Allied Electronics: http://www.alliedelec.com/lp/120626raso/
An SD Card – You’ll need a regular old SD card to store the operating system and any other files you’ll want to use on your Raspberry Pi. 2GB is the minimum size of SD card you’ll need to run the default operating system, Rhaspbian, but if you are going to be using the Pi heavily, you’ll probably want a bigger SD card to suit your needs. In that case, I would probably recommend at least an 8GB SD card. You can get one at your local electronics store, or bundled with a Raspberry Pi at the above listed vendors.
An HDMI Cable – If you plan on doing more than SSH’ing into your Raspberry Pi, you’ll want an HDMI cable (or an HDMI-to-something adapter) so you can view the device video and audio output. You can get one at your local electronics store, or bundled with a Raspberry Pi.
An SD Card Reader/Writer – If you’re working on a laptop, odds are you’ll already have an SD Card slot to work with. If you don’t, you’ll have to get your hands on an SD Card Read/Write device that you can plug into your computer. You’ll need it to flash the SD Card with whatever operating system you’re going to be using. If you don’t plan on ever needing to reflash your Raspberry Pi, you can buy a pre-formatted SD Card from one of the vendors listed above. Otherwise, you can usually pick up an SD Card Reader at your local electronics store.
A Micro-usb Power Supply – The Raspberry Pi is powered by 5V Micro-usb, so you’ll need to get a power supply. The manual recommends against powering your Raspberry Pi directly from the USB port of your computer, but unless you’re working with a lot of high power peripherals or USB hubs you’ll probably be OK doing so. In either case, the safest bet is to buy a power supply either at one of the retailers above or get a micro-usb power supply (the one used for your cellphone or tablet might be able to power the Raspberry Pi).Ethernet Cable – You’ll want an Ethernet cable for your Pi so you can give it an Internet connection; you’ll at least need to set it up on a local network for remote access. The cables are pretty cheap, and you probably have an extra one lying around somewhere. If you don’t you can pick one up online with your Raspberry Pi or at a local retail store. USB Keyboard/Mouse – This is fairly straightforward. You’ll need a keyboard and mouse to develop on the Pi.
The parts listed above are what you’ll need to get started doing anything with your Raspberry Pi. Once you’ve gotten a hold of these items, you can start looking into developing the next cool Pi Project. Intrepid developers have created everything from robots to low-powered FM transmitters and webservers; they’ve even creating mini-supercomputers by parallelizing many Raspberry Pi’s. Check back again on EEWeb for more Raspberry Pi articles!