Preparing your SD card for the Raspberry Pi

Your typical computer is running an operating system, such as Windows, OS X, or Linux. It’s what starts up when you turn your computer on and it provides your applications access to hardware functions of your computer. For instance, if you’re writing a application that accesses the Internet, you can use the operating system’s functions to do so. You don’t need to understand and write code for every single type of Ethernet or WiFi hardware out there. Like any other computer, the Raspberry Pi also uses an operating system and the “stock” OS is a flavor of Linux called Raspbian. Linux is a great match for Raspberry Pi because it’s free and open source. On one hand, it keeps the price of the platform low, and on the other, it makes it more hackable.

The SD card is important because this is where the Raspberry Pi keeps its operating system and is also where you will store your documents and programs.  The Raspberry Pi will not start without a properly formatted SD Card, containing the bootloader and a suitable operating system.This is very different from most computers and it is what many people find the most daunting part of setting up their Raspberry Pi. It is actually very straightforward—just different!

Warning! When you write the Raspberry Pi image to your SD card you will lose all data that was on the card.

The following instructions are for Windows users.Linux and Mac users can find instructions at : www.raspberrypi.org/downloads

1. Download the Raspberry Pi operating system
The recommended OS is called Raspbian. Download it here

2. Unzip the file that you just downloaded
a) Right click on the file and choose “Extract all”.
b) Follow the instructions—you will end up with a file ending in .img .This .img file can only be written to your SD card by special disk imaging software, so…

3. Download the Win32DiskImager software
a) Download win32diskimager-binary.zip (currently version 0.6) from: https://launchpad.net/win32-image-writer/+download
b) Unzip it in the same way you did the Raspbian .zip file
c) You now have a new folder called win32diskimager-binary . You are now ready to write the Raspbian image to your SD card.

4. Writing Raspbian to the SD card
a) Plug your SD card into your PC
b) In the folder you made in step 3(b), run the file named Win32DiskImager.exe
(in Windows Vista, 7 and 8 we recommend that you right-click this file and choose “Run as administrator”). You will see something like this:

c) If the SD card (Device) you are using isn’t found automatically then click on the drop down box and select it

d) In the Image File box, choose the Raspbian .img file that you downloaded

e) Click Write
f) After a few minutes you will have an SD card that you can use in your Raspberry Pi

5. Booting your Raspberry Pi for the first time
a) Follow the Quick start guide on page 1
b) On first boot you will come to the Raspi-config window
c) Change settings such as timezone and locale if you want
d) Finally, select the second choice: expand_rootfs and say ‘yes’ to a reboot
e) The Raspberry Pi will reboot and you will see raspberrypi login:
f) Type: pi
g) You will be asked for your Password
h) Type: raspberry
i) You will then see the prompt: pi@raspberry ~ $
j) Start the desktop by typing: startx
k) You will find yourself in a familiar-but-different desktop environment.
l) Experiment, explore and have fun!

Raspberry Pi

People were skeptical of the Raspberry Pi when it was first announced that a credit-card sized computer for $35 sounded like a fantasy. Which is why, when it started shipping, the Raspberry Pi created a sensation of excitement. The demands for the minicomputer was outperforming what the foundation had expected. So, what is about the Raspberry Pi that tests the patience of a hardware-enthusiast?
One can use this device to watch videos, surf the web, or to hack, learn and make an open source project with the board. The Raspberry Pi is a flexible platform with tremendous support for fun, utility and experimentation. Here are just a few different ways how a Raspberry Pi can be used.

General Purpose Computing
In fact, Raspberry Pi is itself a computer and you can use it as one, make the pi boot into a graphical desktop environment with a web browser, which is lot of what we use computers for these days. In addition, install variety of software like LibreOffice productivity suite for working with documentation and spreadsheets.

Learning to Program

Raspberry Pi is meant as an educational tool to encourage young generation to experiment with the computers. It comes pre-loaded with interpreters and compilers for Python and Scratch (graphical programming language from MIT).
But you are not limited to Python and Scratch, you can write programs for Raspberry Pi in many different programming languages like C, Ruby, Java and Perl.

Project Platform

The Raspberry Pi distinguishes itself from a regular computer not only in its price, size, processor and architecture, but also because it has the ability to integrate with electronic projects.

Media Center

The Raspberry Pi has both HDMI and composite video outputs, it's easy to connect to televisions. It has enough processing power to play full screen video in high definition. To enable a Raspberry Pi as a media center, XBMC (Xbox Media Center) have ported their project to the Raspberry Pi. XBMC can play many different media formats and its interface is designed extremely friendly with large buttons so that it can be easily controlled from the couch.

Raspberry Pi, a microcomputer is based on the ARM processors that uses a family of instruction set architectures based on a Reduced Instruction Set Computing (RISC) developed by a British company, ARM Holdings.
The term RISC abbreviates Reduced Instruction Set Computing. It is focused on a small set of instructions which simplifies the hardware design and improves the processor performance.


Where can you buy it from?

In the context of Nepal, Raspberry Pi can be purchased from Himalayan Solution Industry, Gyaneshwor (Contact: 9841827527).

Despite being a $35 microcomputer, it is a little expensive in Nepal. But, if you have contact with friends and family abroad, then shipping via online shopping stores like Amazon would be sensible and more economical.



Source: Electronics Project Club Magazine (KEC)

Difference Between Microcontroller and Microprocessor

The term microprocessor and microcontroller have always been confused with each other. Both of them have been designed for real time application. They share many common features and at the same time they have significant differences. Both the IC’s i.e., the microprocessor and microcontroller cannot be distinguished by looking at them.  

They are available in different versions starting from 6 pin to as high as 80 to 100 pins or even higher depending on the features.

Difference between microprocessor and microcontroller

Microprocessor is an IC which has only the CPU inside them i.e. only the processing powers such as Intel’s Pentium 1,2,3,4, core 2 duo, i3, i5 etc. These microprocessors don’t have RAM, ROM, and other peripheral on the chip. A system designer has to add them externally to make them functional. Application of microprocessor includes Desktop PC’s, Laptops, notepads etc.

But this is not the case with Microcontrollers. Microcontroller has a CPU, in addition with a fixed amount of RAM, ROM and other peripherals all embedded on a single chip. At times it is also termed as a mini computer or a computer on a single chip. Today different manufacturers produce microcontrollers with a wide range of features available in different versions. Some manufacturers are ATMEL, Microchip, TI, Freescale, Philips, Motorola etc. 

Microcontrollers are designed to perform specific tasks. Specific means applications where the relationship of input and output is defined. Depending on the input, some processing needs to be done and output is delivered. For example, keyboards, mouse, washing machine, digicam, pendrive, remote, microwave, cars, bikes, telephone, mobiles, watches, etc. Since the applications are very specific, they need small resources like RAM, ROM, I/O ports etc and hence can be embedded on a single chip. This in turn reduces the size and the cost.

Microprocessor find applications where tasks are unspecific like developing software, games, websites, photo editing, creating documents etc. In such cases the relationship between input and output is not defined. They need high amount of resources like RAM, ROM, I/O ports etc. 

The clock speed of the Microprocessor is quite high as compared to the microcontroller. Whereas the microcontrollers operate from a few MHz to 30 to 50 MHz, today’s microprocessor operate above 1GHz as they perform complex tasks.

Comparing microcontroller and microprocessor in terms of cost is not justified. Undoubtedly a microcontroller is far cheaper than a microprocessor. However microcontroller cannot be used in place of microprocessor and using a microprocessor is not advised in place of a microcontroller as it makes the application quite costly. Microprocessor cannot be used stand alone. They need other peripherals like RAM, ROM, buffer, I/O ports etc and hence a system designed around a microprocessor is quite costly.