What is Embedded Technology?

Any devices that do not yet contain an embedded computer are likely to have one soon. The competitive advantages are so great that a manufacturer has to have very good reasons to hold back. We will take a look at these ubiquitous "invisible" computers, and at some of the semi-manufactured products that can be used in design work.

When you sit in front of your computer, you actually have one “proper” computer and several “invisible” ones in front of you. The “invisible” computers are in your keyboard, monitor, printer, mouse, scanner, modem/broadband router and, presumably, sundry other gadgets on your desk. You may also have a “semi-invisible” computer in the form of a PDA. And there’s probably a mobile phone on the desk as well, containing anywhere from one to three computers.

When you go to the kitchen to make a cup of coffee you are surrounded by computers. They are in the refrigerator, the freezer, the microwave oven, electronic scales and possibly in your stove, food processor, coffee machine and a host of other household appliances.

The situation is no different when you plop down in front of your TV. There are numerous computers in your television set, VCR, DVD player, MP3 player and even in your various remote controls.

And what about your car? If your car is even remotely modern, it may contain thirty or more computers. They control the engine, door locks, alarm system, lights and many other more or less essential functions.

The same is true at the office and in industry. Fax machines, copiers, postage machines, entry control systems and alarm systems all contain computers, as do industrial robots, factory machinery and essentially everything associated with a production line.

In other words, we are surrounded by computers, although few of them are recognizable as such in the traditional sense. Only a paltry percentage of microprocessors (the key components in nearly every computer) are used in making traditional computers. The rest of them sit there, more or less unseen, and control practically everything. They are embedded or built into something else, and are consequently often referred to as built-in or embedded technology.

Between user and machine

It we compare any modern device with its counterpart from thirty years ago, we will see a big difference. Thirty years ago there was a direct link between the user interface, i.e. the buttons and knobs, and the operations that the device performed. The most advanced such interface was probably the programming section of a washing machine, which could execute a number of operations in sequences.

This was sometimes a sensible approach, but it was impossible to separate what was actually supposed to happen from how it was supposed to happen. Take for example a bread machine. Such a machine would have been hopelessly complicated and unfeasible thirty years ago. It would have contained a mechanical timer, a mechanical programming section and a surfeit of electromechanical gizmos to get the motor to work in different ways. A built-in microcomputer makes it easy to control the motor and the heating coils, and gives the user a sensible interface. With the simplest ones you just pour in the ingredients, set the time when you want the bread to be ready, and push the start button.

We cannot blame the makers of microprocessors for the fact that such an astonishing number of makers of VCRs, TVs, digital cameras and microwave ovens have totally failed to design simple and sensible user interfaces.

Embedded in everything

At present it is generally safe to say that there is an embedded computer and control electronics in every device of any complexity. Or if there is not one now, there probably will be one soon, and anyone who ignores this trend is very likely to lose out to their competition.

Obviously this doesn’t apply to items such as crowbars, hammers and kitchen knives, but there aren’t too many more exceptions. Consider for example common measuring instruments such as calipers and measuring tapes, or tools like drills and grinding machines.

The arguments for including embedded electronics are sometimes weak, but there are a couple that are hard to get around. Controlling basic functions electronically rather than mechanically makes it much easier to create new variants that function in new ways. It’s also much easier to adapt a user interface to different markets and different sets of regulations. The ability to expand one’s market and broaden one’s product offering is viewed as a positive. And, as noted, sometimes it can be necessary to take new steps simply to avoid losing out to the competition.

On the Net

Most devices today are controlled by embedded electronics. The next evolutionary step involves connecting many of these devices to the Internet. This applies mainly to remote scanning and monitoring devices, but sometimes the possibilities in terms of remote diagnostics and upgrades suffice to justify including an Internet connection.

At the office, this means that the copier will send an e-mail to the management when it is out of paper, or if a problem arises. In the latter case the information will also be sent to the service company and, in the best-case scenario, the problem can be solved remotely.

Beverage vending machines that send a message when they need to be restocked are already a reality. This makes it possible to streamline the logistics and save money. Remote scanning of electricity meters is another obvious application where the Internet serves as an inexpensive means of communication to improve efficiency and save money.

If it weren’t such a trite and tired expression, we might say that the possibilities are “limited only by our imaginations.” But it is true that the limits are no longer technical. Most things can be done; the hard part is deciding what to do. And the benefits for anyone who can come up with something that has a major impact are great.

Tools and semi-manufactured products

How does one go about building and programming these embedded computers? The process differs greatly from company to company, and from industry to industry. One common feature is that they all need one or more microprocessors, control electronics for input and output units, and software for the processor(s). The more advanced systems require some sort of operating system to maintain control of the application-specific software.

Makers of mobile telephones and PDAs have never had a choice. Electronics comprise the main components in their products, and these companies are essentially electronics companies. Given the huge volumes they deal with, they often use proprietary circuits in which the microprocessor is included as a building block. These companies also develop their own proprietary operating systems, although the current trend is toward standardized operating systems such as Symbian, OSE, Linux, Windows CE or PalmOS. Makers of consumer products such as DVD- and MP3-players operate under essentially the same conditions, but they are more likely to use proprietary operating systems or systems like Linux and VxWorks.

Electronics have arrived “after the fact” in vehicle applications. The requirements in terms of environmental tolerance are strict, and software bugs can be frightfully costly. The volumes in question with regard to cars are huge, and this is reflected in the way they are built. The volumes associated with trucks/construction machinery are lower, and the requirements in terms of flexibility are much stricter. Reliable real-time operating systems are a prerequisite.

Semi-manufactured products are often used in industrial and telecom systems. Flexible card systems and operating systems mean that it is not necessary to start from scratch each time. Card-based computer systems like VME, Compact PCI, PC104 and Advanced TCA can be used to enhance the hardware. PC cards are often being used more and more often in commercial or industrial variants. The operating systems used include VxWorks, QNX, Integrity, Linux and LynuxWorks, although Windows and Windows CE are being used as well.

Stricter requirements

Regular PCs can also be used in an embedded context in some cases, although this is usually not feasible. There are many reasons for this, including the following:

  • Power consumption. Battery-operated systems require extremely low power consumption, and thus need special energy-efficient microprocessors. In telecom systems in, for example, base stations, it is essential to pack the electronics in tightly, which necessitates the use of energy-efficient cooling systems.
  • Real-time requirements. Regular computer operating systems such as Windows XP have long response times and are consequently impractical for time-critical control operations. Real-time operating systems like VxWorks, OSE, PSOS, LynuxWorks, Integrity etc. have been developed for use in control systems.
  • Service life. Consumer products such as PC computers are constantly changing. Substantially longer service lives are a requirement in industrial contexts. Manufacturers have neither the time nor the money to re-verify and re-certify a system just because the components involved are constantly changing.
  • Environmental requirements. Form factors and connectors must comply with the applicable standards in industrial and telecom contexts. European standards and the 19” cabinet are the most common such requirements.
  • And, last but not least, reliability. No one would accept having to constantly be pressing Ctrl-Alt-Delete for their car, industrial robot or freezer. Embedded computers do not need to look like computers, but they have to work properly much more reliably than regular computers.

By Göte Fagerfjäll/Elektronik i Norden