Getting started with Raspberry Pi

by Abhishek Bhatnagar

Unless you live on Mars, you’ve probably heard of Raspberry Pi by now. I was one of the lucky 1000 who got dibs on the first batch of these, and mine shipped in four days ago. With the off chance that you are indeed a Martian, I’ll do a brief introduction to the project here.

If you already have yours, and just want to get it running, skip to the Making It Work section


The Raspberry Pi Foundation is a non-profit based in Cambridge, UK with a stated goal to “promote the study of computer science and related topics, especially at school level, and to put the fun back into learning computing”. They used Broadcom’s BCM2835 system on a chip which contains

  • the ARM1176JZF-S 700 MHz processor
  • a GPU
  • 256MB RAM

In case you’re wondering, that’s exactly what a ‘system on a chip’ is – a chip that contains the basic components that are usually part of computers systems, such as a processor, RAM, ROM, etc. Using this design along with an SD Card for a hard drive, they produced a Model A and a Model B.

The differences between the two are the following:

Model A Model B
Cost $25 $35
USB Ports 1 2
Network None Ethernet
Power Rating 500mA 700mA

They started selling ‘Model B’ first, and here is what mine looks like. I have placed it next to an Arduino duemilanove for comparison of size.

Raspberry Pi (top) with Arduino Duemilanove (bottom)

Making it Work
All that comes in the box is a Raspi, and two pages to help you get started. You need to append this with

  • a power source
  • an SD Card (or SDHC)

The Power Source needs to be 5V and at least 700mA for Model B (500mA for Model A) with a micro-USB end. If you have an Android, Blackberry or Nokia phone, you’re probably in luck because your phone charger is likely to work. In 2010, GSMA got industry leaders to agree on standardization of cell phone chargers. Everyone agreed, but some companied have yet to implement this. Anyway, in general, be sure to pick a 5V adapter with at least a 700mA rating. Current, as opposed to voltage, in pulled in as needed, so your power source could even be 1A or 20A, and work properly, as long as your voltage is correct.

The SD card requires at least 4GB of space, but should probably be a minimum of 8GB. It needs to have the operating system pre-installed on it, and hence you need to prep it. I followed the excellent guide here to get mine running. You should download the actual OS from RaspberryPi’s download page. Your options are:

  • Debian Squeeze – recommended for now
  • Arch Linux ARM
  • QtonPi
  • Fedora 14 Remix – soon to be the recommended OS, but still buggy

Once you have the SD card done, you’re good to go. Hookup your power, HDMI or Composite, Network (optional), USB keyboard/mouse (I use a wireless port, so one USB), and hit the power button on your socket. After 3 seconds, you should see a Linux boot screen. Once you login, type ‘startx’ to start X and see a GUI.

And there you have it, a computer with a powerful GPU the size of a credit card all for $35. The Raspberry Pi Foundation sees an application of their product in education, especially in the third world. While that is absolutely likely, it has several other applications as well.

I personally intend on using it as the brain of the Quadcopter I’m working on with Chris Tuckwood.