As the market share of linux is increasing seamlessly , not only PC based or server based Linux versions are in demand, but a there is a great demand of compact low power Linux devices. So as the computing power needed is high in compact size, the developers are working on different SoCs like TI Sitara, Qualcomm snapdragon, Broadcomm MediaTek etc from different vendors. But now manufacturers have came out with ready to work development boards of this platforms. They are providing very general purpose development board with their SoC that works on compatible OS such as Linux, Android, Win CE. So developers dont need to design the hardware first and they can directly works on steps such as driver development, Bring up, programming etc. Commanly they include some SoC, audio/video decoders, some memories, gpios, USB, Ethernet connectivity. So they are called single board computers. These all are open source boards. Top 5 of them are as below:
Raspberry pi: model B+
Raspberry Pi Model B+ Featuring the ARM1176JZF-S Running at 700MHz, with 512MB of RAM. The RASPBRRY-MODB+-512M is a credit card sized computer that plugs into your TV and a keyboard, its like a little PC which can be used for many of the things that your desktop PC does, like spreadsheets, word processing and games. It also plays high definition video. The design is based around a Broadcom BCM2835 SoC, which includes an ARM1176JZF-S 700MHz processor, VideoCore IV GPU, and 512Mbytes of RAM.
The specs are lower compared to some of boards, but the biggest advantage of raspberry pi is the largest community support.
The design does not include a built in hard disk or solid state drive, instead relying on a microSD card for booting and long term storage. This board is intended to run Linux kernel based operating systems.
The price is 40$. But as the demand is increasing so many new even more powerful boards are coming out.
The Beaglebone Black is a low-cost credit-card-sized development platform with good support from a fast growing community. The Beaglebone Black differs slightly from the regular version by providing you with an onboard micro HDMI port, 512MB of DDR3L DRAM, 4GB onboard flash memory, an AM3358 processor at 1GHz, and making JTAG optional with a user supplied header. Ultimately, the Beaglebone Black is still perfect for physical computing and smaller embedded applications.
With plenty of I/O and processing power for real-time analysis provided by the TI Sitara™ AM3358 ARM® Cortex™-A8 processor, Beaglebone Black can be complemented with cape plug-in boards which augment Black’s functionality.They’re called capes because Underdog is a beagle and he wears a cape.It has the second largest community support after raspberry pi.
You can also run Android and many RTOS on it. And as it is based on Texas Instruments SoC, so much good support and downloads are available from TI.
Its price is 55$
Cubieboard is mini pc development board, which is based on Allwinner A10 SoC, small size (10x6cm), hacker friendly, extendable and very low-cost. Compare with Raspberry Pi, it has higher performance, SATA supported and 96 extended interface.
If you plan to assemble a small computer, you can try using this small ARM platform cubieboard. It supports Ubuntu and other Linux distributions; you could use it like an ordinary computer operation. At the same time, the platform also supports Android 4.0 Ice Cream Sandwich system and has bulit-in IR sensor, can be used as “Android TV”.
On the board you can see the Ethernet and USB connectors, the two audio jacks (input and output), the micro SDCard connector (up to 64 GB). On the top of the figure you can see the SATA connector that can withstand a 2.5-inch disk (if you use larger size disks you need to feed them externally). Finally, a little curiosity, in the upper left we see an infrared sensor. This type of sensor was very common in laptops and vintage mobile phones, then they disappeared. In this case, however, the idea is not so farfetched as it might appear at first glance, as it allows us to use a built in infrared remote control applications to be integrated into home automation and such.
The board comes with the Android operating system pre-installed (in the NAND memory partition). If there is an SD card with a valid boot partition the operating system it’s loaded and launched, otherwise it goes with Android.
It costs 60$
Galileo is a microcontroller board based on the Intel® Quark SoC X1000 Application Processor, a 32-bit Intel Pentium-class system on a chip. It’s the first board based on Intel® architecture designed to be hardware and software pin-compatible with Arduino shields designed for the Uno R3. Digital pins 0 to 13 (and the adjacent AREF and GND pins), Analog inputs 0 to 5, the power header, ICSP header, and the UART port pins (0 and 1), are all in the same locations as on the Arduino Uno R3. This is also known as the Arduino 1.0 pinout.
Galileo is designed to support shields that operate at either 3.3V or 5V. The core operating voltage of Galileo is 3.3V. However, a jumper on the board enables voltage translation to 5V at the I/O pins. This provides support for 5V Uno shields and is the default behavior. By switching the jumper position, the voltage translation can be disabled to provide 3.3V operation at the I/O pins.
Of course, the Galileo board is also software compatible with the Arduino Software Development Environment (IDE), which makes usability and introduction a snap. In addition to Arduino hardware and software compatibility, the Galileo board has several PC industry standard I/O ports and features to expand native usage and capabilities beyond the Arduino shield ecosystem. A full sized mini-PCI Express slot, 100Mb Ethernet port, Micro-SD slot, RS-232 serial port, USB Host port, USB Client port, and 8MByte NOR flash come standard on the board.
It costs 70$.
It is the latest development board in the market. It promises to be very powerful than other boards. As its cost is also high, sometimes it may lack some market share of beginers.
The company sources have shown the comparison with other boards in the market. UDOO is a single board computer that can be used both with Android and Linux, paired with an Arduino-compatible processor. It is a powerful prototyping board for software development and design; it’s easy to use and allows developing projects with minimum knowledge of hardware design. UDOO merges different computing worlds together: each one has its proper strengths and weak points, but all of them are useful in today’s life for educational purposes as well as Do-It-Yourself (DIY) and quick prototyping. UDOO is an open hardware, low-cost platform equipped with an ARM i.MX6 Freescale processor, and an Arduino Due compatible section based on ATMEL SAM3X8E ARM processor, all this available on the same board!
It has several versions ranging from 99$ to 135$.
Finally the choice to decide the best among these depends on your application requirements such as computing power, cost, power consumption etc. Also it depends on your capability to use these boards, such as if you are a beginner, then you should go fot boards like beaglebone and raspberry pi who have larger community support. So that you dont stuck anywhere and get more tutorial and all.