Raspberry Pi - a open source hardware

In my previous post I had given you a rough idea of what exactly is Open Source Hardware and explained the design and architecture of Audrino - one of such kinds. In this post I shall brief you on another example of the Open Source Hardware.

The Raspberry Pi is a credit card-sized single-board computer developed in the UK by the Raspberry Pi Foundation. The main intention behind its development was to promote the training of basic computer science in schools to encourage students from all over the world to learn how computer works, how to program, how to manipulate the electronic world around them.

Design:

The Raspberry Pi uses a Broadcom BCM2835 system on a chip (SoC) It does not comprise a built-in storage device like a hard disk or solid-state drive, but it uses an external SD card for booting and persistent storage.

The Raspberry Pi does not have an inbuilt real-time clock as well. So an OS must use a network time server, or ask the user for time information at boot time to get access to time and date for file time and date stamping.

RAM Size

On the older beta model B boards, 128 MB was allocated by default to the GPU, leaving 128 MB for the CPU. On the first 256 MB release model B (and Model A), three different splits were possible.

The Model A can connect to the network either with the help of the Wi-Fi adapter or via an external USB Ethernet. It does not have a (RJ45) Ethernet port. On the model B an Ethernet port is provided by a built-in USB Ethernet adapter.

Overclocking the Pi:

Most Raspberry Pi devices can be overclocked to 800 MHz and some even higher to 1000 MHz. The newer versions of the firmware contain the option to choose between five overclock ("turbo") presets. The different overclocking configurations are as follows:
• None; 700 MHz ARM, 250 MHz core, 400 MHz SDRAM, 0 overvolt,
• Modest; 800 MHz ARM, 250 MHz core, 400 MHz SDRAM, 0 overvolt,
• Medium; 900 MHz ARM, 250 MHz core, 450 MHz SDRAM, 2 overvolt,
• High; 950 MHz ARM, 250 MHz core, 450 MHz SDRAM, 6 overvolt,
• Turbo; 1000 MHz ARM, 500 MHz core, 600 MHz SDRAM, 6 overvolt

The overclocking is usually done by monitoring the core temperature of the chip, and the CPU load and dynamically adjusting clock speeds and the core voltage. When the demand is low on the CPU, or it is running too hot, the performance is throttled, but if the CPU has much to do, and the chip's temperature is acceptable, performance is temporarily increased.

Operating Systems for Pi:

The Raspberry Pi predominantly uses Linux kernel-based operating systems, some of which are mentioned below:
• Pidora – a combination of Pi and Fedora
• RISC OS
• Raspbmc
• Raspbian
• Archlinux ARM used by latest version 6
• Minepion – Dedicated operating system for mining cryptocurrency
• Kali Linux - designed for digital forensics and penetration testing

Final Word:

We can make use of the standard USB keyboards and mice are compatible with the Raspberry Pi using the USB ports provided. Thus giving the full freedom to create programs for the Pi without the need of an extra hardware to program it. The approximate price of the Raspbbery Pi model A is around 25$ and the model B ranges between 34$ to 36$.