Getting Started
These devices are typically used with backplanes, which allow a single board computer to be easily connected to systems and in a very compact arrangement.
While single board computers are typically less powerful than standard, tower computers, they are more than adequate for the purposes they are used toward in industry. Some of these devices are also excellent experimentation and teaching tools, owing to their low cost, simplicity and the fact that many of them can easily be connected to other hardware.
What is a Single Board Computer
A single board computer is differentiated from a desktop or personal computer not by what it is capable of, but by the way it is designed. A single board computer has all of the elements of a complete computer contained within one single circuit board. Conversely, desktop computers have motherboards with slots for the basic components of the computer. On a desktop computer, the processor, memory, storage, input and output devices and other basic components attach via sockets on the motherboard. On a single board design, everything is self-contained.
Single board computers are also expanded in their capabilities differently than desktop computers. On a desktop computer, adding capability to the motherboard is typically accomplished by plugging a peripheral device into a slot on the motherboard. A high end video card, for instance, will be plugged into a specialized slot on the motherboard. On a single board computer, this and the other components required on the computer are simply a part of the circuit board and the device is ready to go as is.
Single board computers come in a huge range of different capacities. Because some of them are used to control very simple processes, some single board computers are very slow and limited compared to the average desktop computer.
What Are Single Board Computers Used For?
Single board computers are frequently employed in embedded applications. An embedded computer cannot be expanded upon and contains only the input and output capabilities it needs for the task for which it is designed. For example, a vending machine might have an embedded single board computer in it to control the functions of the vending machine, but there would be no provision to add more hardware to the computer to expand its capabilities.
In many cases, single board computers are plugged into a backplane. The backplane allows for input and output devices to be attached to the computer. Single board computers are frequently used in rack systems, which allows for reliable and fast integration into a system.
Why Single Board Computers Are Used in Industry
Single board computers have all of the capacity required to perform most automation tasks and specialized designs are widely available. These computers have some significant advantages over using a typical desktop computer for the applications to which single board computers are usually put.
Single board computers are very small. This allows them to be embedded in devices where space is very limited. The computers are also very efficient, giving them an edge where saving on power is concerned. In addition to these advantages, single board computers are self-contained, making them very reliable under trying environmental conditions.
Despite the fact that single board computers have generally less capacity than a multi-board computer, they are quite often more expensive than a multi-board computer. Single board computers are somewhat specialized equipment, which means that they are not manufactured in the same quantities as are standard multi-board motherboards. The reliability of these computers, however, make them very cost effective solutions for industry and, because they are self-contained, it is relatively easy to swap one out for the other if a computer needs to be replaced.
Various backplane options allow these computers to be expanded tremendously in their capabilities, so they are not overly limited by their designs. In fact, with certain types of backplane arrangements, single board computers can actually provide for more expanded capacity than can a standard multi-board computer and in a much more compact amount of space.
Variations
There are different types of single board computers available. Among the most common types are those that are designed to use backplane connections. These come in designs that work with various architectures, including Intel architectures and others. Some of the names of these designs include the PXI, VXI and the CompactPCI types, all of which are widely available.
With the backplanes, the computer is capable of working with connections including PCIX, PCI and others.
A System Host Board is one that meets the PICMG 1.3 specification. PICMG version 1.2 offered PCIX support. Prior versions offered support for PCI and IFA connections.
Some single board computers include hard drives and some do not. Those that do not are typically operated completely off of a network. Other form factor options include Mini-ITX, PC/104, VMEbus, VPX, Embedded Compact Extended, and AdvancedTCA.
Specifications
Single board computers can be purchased to meet a huge variety of different needs. Some of them come with I/O interfaces that are specifically geared toward audio applications, networking applications, wireless applications and so forth. Being able to purchase these devices already set up for such uses makes them even more convenient.
While single board computers are generally differentiated from multi-board computers by having all of their components installed on the single board, some of them do come with expansion slots. These expansion slots include popular design such as microSD, Mini PCI, PCI, ISA, PCI Express and others. They can also be purchased based on the specific type of ports they come with, such as CRT, DVI, HDMI, VGA and so forth.
Where the basics of computers are concerned, the specifications are very similar to what one would assess if they were purchasing a desktop computer. Processor clock speed, front side bus clock speed, the type of processor used in the device, the amount of memory it can support and other considerations are all taken into account when purchasing these devices. Because many of them are used in such simple applications, purchasing single board computers with comparatively low power versus a desktop is quite often a viable means of saving money.
Purchasing
Because single board computers are used in some very trying environmental conditions, it�s important to make certain that any design chosen is able to provide reliable service under the expected stresses. Minimum and maximum operating temperatures, the size of the device, the type of sockets that it has and other factors will all play into whether or not it is suitable for any particular application.
While single board computers are inherently less flexible than multi-board designs as far as expandability goes, the options for single board computers with many different expansion slots are rapidly increasing. In addition to this, there are many very specialized designs available, providing very powerful solutions for embedded applications where space is at a premium.
Single board computers will typically not have the upper range of performance that one will see with desktop computers, but they are getting very powerful with modern developments. Options such as the BeagleBoard, Raspberry Pi and others also make these very accessible, allowing a developer to get an entire computer on a very small circuit board that can be easily expanded for the purposes of actually building a practical appliance or simply experimenting. As is the case with most electronics, the price on single board computers has tended to drop over time even as the capabilities have expanded.
