About embedded systems – in simple terms (3)

mooro 2 pus

Continuation (3) , Beginning No.1

National defence. Protection of public order

In the system of state border protection, alarms must be adequately responded, and this must be done on time. Situation monitoring through surveillance cameras does not ensure proper control. A growing demand (and possibilities) is observed to use real-time systems for assessing the level of danger thus limiting the number of errors caused by human factor. Night vision devices, radio detecting and ranging, – all this are now controlled by the systems that perform real-time processing of the information received.

Self-contained guidance systems used for ballistic missiles are a perfect example or ESs (embedded systems) integration (Figure No. 15).

Figure No.15. Launch of ballistic missile Trident.
Taken from Wikipedia.

The latest sea-based solid propelled ballistic missile R30 3M30 Bulava-30 (Figure No. 16), that is dislocated at submarines, is characterized by a payload of 6 hypersonic manoeuvrable independently targeted nuclear warheads.

In order to avoid a backfire from the target, missile has to manoeuvre at high speed and accelerations, and ensure the correct trajectory towards the selected target without having a connection with the command point. This has become possible only with the use of high-speed ESs that operate on the basis of a device integrating the readings of the accelerometer and laser gyroscope.

Figure No. 16. Launching of Bulava.
Taken from: www.diena.lt
Figure No. 17. Demonstrating the manoeuvrability of the ballistic missile Bulava.
Taken from: www.dailymail.co.uk

Using the above mentioned technologies of ballistic missiles in the manoeuvrable projectiles launched from self-propelled armed devices became possible only after miniaturisation of ES and reduction of their production costs. The systems of target recognition, calculation of projectile trajectory, radiolocation, thermal source tracking, guidance (“fire and forget” system), and drive systems of the contemporary tanks (Figure No. 18) – all of these are controlled with the help of ES board computer.

During the exhibition Litexpo in Parodų rūmai a decade ago, a computer system was demonstrated that identified and tracked the location of the selected objects in a crowded space in real time. It is far more reliable than a distracted policeman who losses his suspect for a couple of doughnuts. Hardly can someone avoid the fierce eye of this completely dispassionate tracer. On the other side, these systems are extremely useful for totalitarian regimes.

Figure No. 18. M1 Abrams – a tank equipped with sophisticated electronics.
Taken from: http://weapons-system.blogspot.com

The tools of police detectives (who are equipped not only with shoes, socks, bicycles, and retirement pension after 20 years of “service”) include such devices as real-time voice analyzers (you do not need to put any detectors, needles, or wires on ears, nose, or fingers) that identify essential properties of a person and assess the probability of lying based on the voice over the phone. Tools used by law enforcement forces – odour analyzers, high-performance liquid and gas chromatographs, DNA sequenators, mass spectrometers – are all composed of more or less high-speed ES modules.


Electronic integrated circuit cards (Figure No. 19) will soon replace the unsafe magnetic debit cards in the whole world (except for USA, maybe).

Chip is a small device (microprocessor); semiconductor crystal in electronics; integrated circuit, or a special microprocessor in technical literature.

Magnetic debit cards are easy to scan and make a duplicate using illegal equipment. Chip cards are completely safe provided you do not write your pin code somewhere. There is also a type of chip cards that are contactless. The principle of operation for this type of cards is based on magnetic induction, i.e. the current induced in the coil triggers the microprocessor which exchange information with the inducing device. The same principle of magnetic induction is applied in entrance systems. There is no need even to remove the card from your wallet; it is enough to get close enough to the scanning device.

Currently in Japan people can pay for parking or access to the subway via their mobile phones with the special ES installed (there were some similar attempts in Lithuanian also).  According to the information published in mass media, such contactless way of payment is completely safe. The phone and the ATM exchange information packages.

Figure No. 19 Chip (smart) payment card.
Taken from: http://lt.wikipedia.org/wiki/Mokėjimo_kortelėThe phone and the ATM exchange information packages.

Chip cards are closely related to the idea of electronic money for one time payments (entrance to subway, parking fees) via mobile phone. The account can be constantly replenished via ATM. E-money goes from one device into another according to a certain algorithm without connection to the bank. It is very comfortable since no pin code entry is needed. According to some experts, the use of this type of system is rapidly spreading in South Korea.

The safety issues related to having such account are solved as follows: since a mobile phone is capacious enough to incorporate complex ES, certain systems are designed to analyse owner’s manner of walking at various speeds and in different situations according to the readings of the installed accelerometer (mentioned above). Phones having an accelerometer installed are not a new concept; however their usage was limited to light signalling following the direction of the device thus creating the illusions of letters and figures in the space.

Thus when the phone gets into the wrong hands, the ES by monitoring the behavioural changes easily identifies the change of the owner and blocks the accounts, most probably giving a notice thereof to the bank. But what is going to happen with this system, if the owner brakes his leg and starts limping? It was mentioned, that before blocking the amount, the phone may ask to enter the pin code.

Variety and bandwidth of ES microprocessor-based devices

If we compare the scarce possibilities of the digital “super” systems in the late 70s with those of the modern computing giants, the apparent progress was hard to imagine. If a task could not fit into a single or into one and a half minute of machine time, it was usually put to a long queue by machine operators for a long and boring waiting time. But in the meantime, the supercomputer BESM-6 (Figure No. 20) might crash, or its operation might be suspended for some other reasons. And if the task formulated takes more than 5 min, then it is left for the night or even for the weekend. And there again we have a queue of tasks waiting for their turn.

Figure No. 20 Machine hall of the soviet supercomputer BESM-6, developed in 1966, which had been used for 20 years.
The previous models, e.g. BESM-4 in the Faculty of Physics and Mathematics (Vilnius University) were operating on the basis of transistor circuits.

When developing algorithms for their minute-long tasks (and especially for the longer ones) programmers used various kinds of tricks, i.e. they had to optimize the program code. They managed to accelerate the programs using assembler code, or redesigned the cycles in the program so that the machine time was reduced by ten or even twenty and more times.

moor's low
Figure No. 21 Moore’s Law. http://www.cmg.org

The advance in microprocessor (MP) technology opened new opportunities for miniaturisation, reducing the dimensions of computing devices, and developing new powerful tools for personal use. The power of microprocessors depended on the density of elements incorporated, i.e. the number of elements per unit of area, and technologies of cooling solutions. The power for computers doubled every 18 months (Figure No. 21. Moore’s law).

When the first personal computers emerged in Lithuania, the problems related to program acceleration ceased: there is no difference for the programmer whether machine performs a task within 01 s or 20s if the customer does not notice such difference.

However, with the wider application of ES microprocessors the situation reminds the “good old times”. Real-time systems are required to save time, only this time even microseconds matters. To optimize the programs highly professional specialists –program code analysts- are required for troubleshooting.

Figure No. 22. The first microprocessor Intel 4004, Taken from: http://www.cedmagic.com
Figure No. 23. Modern microprocessor Cyrix486dx2 in the process of manufacture, – coated with protective layers, and prepared for further chemical processing. Taken from: http://micro.magnet.fsu.edu

In order to have a better picture of the fantastic bandwidth of modern ES modules, let us take a look into how a simple mass spectrometer works. With the help of laser pulse, a drop of test material (piko grams) that is fed to beam is burst, molecules are fragmented, and fragments are ionized. Ions are accelerated in an electrical field by giving the fragments of equal load even amount of energy.

Figure No. 24. Principal scheme of mass spectrometer.
No.13 -laser, Nr. 14 – particle of test material,
No. 20 – ion reflector, Nr. 32 – ion detector

However, molecules dart to the detector module at different speeds which depend on the fragment mass (load/mass ratio, to be specific). Thus the detector module (marked as No. 32 in the Figure No. 24) with a high-speed MP does not lose itself in this cloud of charged fragments, and counts all the amounts of the fragments and the time they spent for a distance of as little as 80-100 cm. Measuring accuracy allows “weighting” the molecules and determining for example, which complex of organic molecule contains isotope 58Ni, and which 58Fe despite the fact that the difference in the masses of these fragments is only 0.002 of atomic mass unit.

The first spectrometers employed slightly different principles of operation: separation of charged molecule fragments in combined fields of electric and magnetic forces. They used to be popular some time ago before the high-speed MS emerged. However, even at those times, they used ES-controlled modules. And they are still used for specific tasks.

Figure No. 25. Main part of LHC.
It stretches for more than 60 km beneath the Franco-Swiss border.

In the following chapters, I will try to show you some possibilities of ES microprocessors that might appear as though taken from fiction. This includes computing of separate molecules in a flow, or determining on which side lies the molecule (organic) on a specific plate.

There was an event reported in media when certain hardware (containing special high-speed ES, of course) “found” the place of the electron in molecular orbit (despite the fact that we were taught in schools that electron is delocalized in the orbit, and is spread across a certain part of space and cannot physically be in a single place; an only a possibility of its presence can be determined). Currently, these high-speed systems are employed in Large Hadron Collider (LHC) for years to come.

Another unexpected turn in the development of IT tools was a colour image from the world where there should be no colours at all. I am talking about various kinds of electron microscopes. After all, the objects are several times smaller than the wavelength of light. But if we think, what the colours are for real, we arrive at the conclusion that colours are related to physiological perception. At this point, everything becomes simpler. A separate colour code is attributed to the surface points having different electronic properties. And it is up to the personal physiology of the subject how he perceives that code. However, the great colour contrast in the picture (Figure No. 26) is quite surprising.

plauciu Vezys
Figure No. 26. Cancerous cell in lungs “recorded” by electron microscope. Taken from: http://www.technologijos.lt

Similar images are obtained with the use of Atomic Force Microscope (AFM). During the scanning of the surface, electron tunnelling takes place. In Figure No. 27, on the right of the organic compound an image of five condensed benzene rings is observed while on the left – a schematic view of the scanning “needle” is presented.

Such delicate scanning became possible as a result of “dosing” the mechanic motion in the macro-world, i.e. to control it at the accuracy that is several times higher compared to the quantum world . This kind of device can also be used not only for observation but also for mechanical work: it can be used for moving the atoms from one place to another in extreme accuracy, or for designing microprocessor parts (which is possible but not viable, – it would take up to several months to put together the simplest circuit of logic gate circuit).

Figure No. 27. Single-molecule image obtained with AFM
(it is claimed in the article, such image was obtained for the first time); Schematic representation of AFM.
Taken from: http://www.technologijos.lt

Thus, in all these examples high-speed ES compute and measure the properties of electrons that fly from the object at various angles and speeds, then attributes a certain code to the surface element in the computer memory that may be further attributed a colour index.

Continuation follows.