How a software interacts with hardware? - Basics of Computer Electronics

In modern computer programming, every software is written using a software programming language. This text program (called high level language) is then converted into runnable (executable - low level language) format by special softwares called compilers(or interpreters). The specialty of this low level language is that it could be understood by a hardware (precisely a microprocessor - a type of electronic component which can perform electronic operation based on software codes). The microprocessor reads the program (low level) and perform the corresponding action.

Now the microprocessor understands a particular code by reading (actually, its sensing electronically) the bits in the particular code. For example if a microprocessor is made in such a way that it will make its 5th pin to +5 voltage level when it reads a bit sequence 0010011, then the processor perform the action whenever it reads a 0010011 in the code. In this way the actions to be performed by a particular microprocessor and the corresponding bit sequence is defined at the time the microprocessor is manufactured. As you know, in a computer system, the microprocessor is the brain, so all the operations are carried out by it.

The computer peripherals (like mouse, keyboard etc) are identified by using configuration files called drivers. These files contain the information that is to be used for interacting with the hardware. The Operating System (windows, linux etc) controls and monitors the peripheral (hardware) control and management.

Best soldering practice tips for the beginners

These are few soldering tips for the beginners in electronics.

1. Keep the soldering surface of the PCB (printed circuit board) clean. If you find that the surface is covered with some corrosive coating, then use a pen-knife and gently remove the contamination over the surface. You should do this carefully so as to avoid damaging the metal lining/plating of the PCB.

2. Never use too much or too little solder-lead for solder joints. Use only the optimum amount of lead so as to keep the component connected firmly to the PCB. Using too much solder may result in a short circuit. Also the circuit will appear ugly in this case. Use of too little solder will result in weak joint or open contacts, which will in turn, affect the working of the circuit.

3. It is not very easy to cut the ‘extra’ legs of the soldered components with a wire-stripper. Moreover it results in imperfect cutting. I recommend using a nail-cutter for this purpose. It will help in doing the cutting job easily and with perfection.

4. Do not use single strand wire for external wiring on PCBs. The reason is that they will break easily. Use suitable multi-strand wire instead (since they have good flexibility, they won’t break so easily). Before soldering, make sure that the insulation is sufficiently removed and the metal strands are properly twisted together at the soldering end of the wire.

5. Use a good quality soldering iron. A good soldering iron will allow the heat to flow to its tip very quickly and effectively thereby giving a better soldering experience. A 25 Watt Soldering iron is the best choice for the electronics beginners. I recommend Soldron iron for Indian hobbyists and Weller SP23LK Marksman for the all International electronics amateurs.  They are two of the best rated soldering irons available in the market. The Soldron iron is available on www.ebay.in or http://www.soldron.com/catalog.php (price around Rs.220-300) and Weller SP23LK Marksman iron on www.amazon.com  (price around 15$ for the iron and 45$ for the Soldering Station).

6. Never do soldering under the fan or near any cooling equipment. This will reduce the tip temperature of the iron and hence the solder-lead will not melt properly, causing a bad soldering experience.

7. Do not keep the soldering iron in contact with the soldering surface for long time. This will damage the electronic component which is being soldered and also it causes oxidants to accumulate on the PCB surface and thereby prevents the solder-lead from attaching to the metal plating of the PCB. As a result the soldering will fail. In this case you have to use a pen-knife to clean the metal surface as explained before.

8. To remove the extra solder attached to the iron-tip, give it a strong shake to the ground (while it is hot). This will cause the molten lead to detach from the iron and fall down. Remember, while doing this, you must be careful about your surroundings since the molten lead will be hot (though for a short time) and might cause damage, if fell on sensitive surfaces.

9. Do not use soldering iron for other purposes like melting plastic or polythene (e.g. for removal of wire insulation), wax, paints etc. It will cause such materials to get attached to the iron-tip and thereby interrupts the heat flow from iron to the solder lead. In this case, you will have to use either a ‘file’ (tool used to sharpen chisels) or a sandpaper to clean the iron-tip.

10. After using for a while, the tip of the soldering iron will wear-off (becomes curvy). This will cause difficulty in soldering. In this case, use a ‘file’ to suitably plain the tip. After long use and repeated ‘filing’, you will find the soldering tip to be very short and thereby causing uneasiness in soldering. In this case, you need to buy a new soldering ‘bit’ (tip) for your iron (provided your soldering iron has an changeable tip). The bit costs only a couple of bucks and is available at almost all electronics stores.