basic equipment to create your own bot

Equipment’s, Elements(Components) and Tools of Electronic to create your own Bot
Before starting create your first own bot.
Knowledge of basic Electronic elements, Equipment’s and tools is very important.
Let’s us study one-by-one all basic elements and tools for our bot.
In this post we will study about all Basic Electronic Equipment’s to measure and operate the logics of a bot will help to create your bots
1. Potentiometer
The resistors we have discussed above have constant resistances, which do not vary unless they are heated too much. A potentiometer is also a resistor, but it has variable resistor which can be changed at will by the user. Potentiometer is rated according to a range of resistances which can be achieved by using it, along with its power rating.

A potentiometer is very useful in applications in which you are not sure of the exact value of the resistance you would require. When only the range required is known, a potentiometer is used and then its resistance is varied so as to get desired output from the circuit.

The resistance of the potentiometer is varied by rotating the ‘shaft’ or ‘knob’ located on its body. Rotating it in one direction increases the resistance, while rotating in opposite direction decreases it.

A potentiometer has three terminals. The resistance between the extreme two terminals is constant, whereas the resistance between either of the end terminals and the middle terminal is variable.
2. Multimeter
In both robotics and electronics, you need to measure three things very frequently:
Continuity between two points
To measure continuity, you should set the multimeter knob to continuity. Then, insert or place the probes of the multimeter in between the points to be checked for continuity. If you hear a beep, that means there is a connection between those two points.

 Turn the knob to point towards the resistance measurement section and select upper value of the resistance randomly. Connect the probes across the points you want to measure the resistance. The resistance is displayed in ohms. If you see a 1, it means that the upper value (or limit) you selected is not appropriate, and the value of the resistance being measured is greater than it. In that case, you need to select a higher upper limit.
For example, if you want to measure a resistance and you set the knob to 20 kilo ohm. If the value of resistance is smaller than 20 kilo ohm, the multimeter screen will give you the value. But if the value of the resistance to be measured is greater than 20 kilo ohm, the multimeter will show 1, and in that case you need to select the 200 kilo ohm limit.

Voltage difference between two points
To check DC voltage difference between two points, set the knob to point in the direction of voltage measurement and hold the probes across the points you want to measure voltage. The upper limit is selected like in the case of resistance.
If the screen shows a voltage value along with a negative sign, it means the polarity is reversed. Interchange the red and black cables and the polarity will be positive.
And all the aforementioned quantities can
You need a multimeter through the easily be measured using a multimeter. The building and troubleshooting stages cost of a multimeter increases with the number of quantities it can measure. However, for basic electronics and robotics purpose a simple and cheap multimeter would suffice. It will cost around `100. A snapshot of such a cheap and easy to use multimeter is given alongside. Also, the sections we would need to use frequently are highlighted.
3. Motor driver
A motor driver is an IC which is capable of providing voltages sufficient enough to drive D.C. motors.  We use a L293D motor driver. The L293D is designed to provide bidirectional drive currents of up to

600mA at voltages from 4.5 V to 36 V. It can also drive inductive loads such as relays, solenoids, dc and bipolar stepping motors, as well as other high-current/high-voltage loads in positive-supply applications
To assemble all the electronic components and elements we need special boards. That are
Breadboards and PCBs(Printed circuit board)
These are most commonly used for building circuits. PCBs stand for printed circuit boards. Rather than using connecting wire and component terminals to form a closed circuit, it is more efficient to use a firm board with a copper coating. The required conductors are drawn by removing copper from the board with a process called etching using a corrosive solution of Ferric Chloride (FeCl3).
4. Breadboards
Instead of PCBs, you could also use breadboards. With breadboards, you don’t have to touch the soldering iron. All you need to do is plug component terminals in and out of the board to make or break connections

. Breadboards have a lot of holes, connected internally into groups. You just have to insert your component’s terminal into these holes – it's as simple as that.
5. PCB (Printed circuit board)
The motherboard of your PC is a standard example of a PCB. The use of breadboards has its own advantages over the use of PCBs. In addition to not having to solder at all, you could proceed onto building circuits once you’ve designed them. Also, you can reuse your components once you are done and save a lot of money.

On the other hand, once you solder the components and make the necessary connections on a PCB, they have longer shelf lives, and would sustain jerks and shocks. Therefore, ideally, circuits are first built on a breadboard, tested, remade and the final design is soldered on a PCB for practical use. Try following the two golden rules to make fool proof circuits on a breadboard:

Use single strand wires (wires with single conductor wires within the insulator coating) instead of wires with multiple strands (fine multiple conductor wires). Use wires having lengths as close as possible to the distance between the two holes to be connected.
Still, if you have doubt of connection between two holes, insert a safety pin
in each of these holes and check the continuity between the safety pins (the probes of a multimeter are too thick to go into any of the holes).

Follow some basic discipline while laying the components on the breadboard
You might be face these Possible problems with breadboards whenever you work with it.
There are some bread boards whose holes are too small, and you can’t insert leads of voltage regulators such as 7805 into it, as its legs are slightly thicker. So be careful when you buy a new breadboard, and if possible, before buying them, check by inserting a 7805 into it.
Even if you buy a new breadboard, some sections of the board may have faulty internal connections. As a result, even a properly assembled circuit may not work as desired. Also, with passage of time, the internal connections of breadboard may get loose. So, it is important to buy a good quality breadboard.
Voltage regulation is also very important factor in both Electronic and Robotics.
So some basic and common voltage regulators are given below.
6. Zener diode voltage regulation
A quick and relatively small method for providing regulated voltage is to use zener diodes. With a zener diode, current does not begin to flow through the load circuitry until the voltage exceeds a certain level (called the breakdown voltage). Voltage over this level is then “shunted” through the zener diode, effectively limiting the voltage to the rest of the circuit. Zener diodes are available in a variety of voltages, such as 3.3, 5.1, 6.2 V and others. A zener diode and resistor can make a simple and inexpensive voltage regulator. Be sure to select the proper wattage for the zener and the proper wattage and resistance for the resistor. Zener diodes are also rated by their tolerance (1 percent and 5 percent are common) and their power rating, in watts. Note the resistor in the schematic shown in the figure given alongside.

This resistor (R) limits the current through the zener, and its value (and wattage) is determined by the current draw from the load, as well as the input and output voltages. The process of determining the correct values and ratings for resistor R and the zener diode is fairly simple and uses the basic electricity rules. The zener voltage rating is, quite obviously, the desired regulated voltage—you may find that the available rated voltages are somewhat awkward (such as 5.1 V), but you should be able to find a value within a few percent of the rated value. Once you know the voltage rating for the zener diode that you are going to use, you can then calculate the value and ratings for R. The zener diode regulator shown in the figure alongside is actually a voltage divider, with the lower portion being a set voltage level. To determine the correct resistance of R, you have to know what the input voltage is and the current that is going to be drawn from the regulator. For example, if you wanted 100 mA at 5.1 V from a 12V power supply, the resistance of R can be calculated as:
VImax = 12-5.1100 ×10-3=69Ω
The closest “standard” resistor value you can get is 68 ohms, which will result in 101 mA being available for the load. With this value in hand, you can now calculate the power being dissipated by the resistor, using the basic power formulas:
V×Imax=6.9×100×10-3=0.69W
Standard resistor power ratings (in watts) are 18, 14, 12 , 1, 2, and so on. A 1-W, 68 ohm resistor would be chosen for this application. The zener diode will also be dissipating power. The voltage drop here is something that you need to decide. To be on the safe side, it is recommended that you assume that the zener diode can have 100 percent of the load current passing through it (when the load circuitry is not attached to the power supply). The power rating for the zener diode is calculated
a simple Zener diode voltage regulator exactly the same way as R:
5.1V×0.101A=0.52 W
For this application, you could probably get away with a ½ W rated zener diode along with the 1 W rated 68 ohm resistor. Working with zener diodes to make power supplies is quite easy, but there is a tremendous price to pay in terms of lost power. In this example, the total power dissipated will be 1.2 W, with 58 percent of it being dissipated through the R resistor. This loss may be unacceptable in a battery-powered robot.
7. Linear voltage regulators
The zener diode regulator can be thought of as a tub of water with a hole at the bottom; the maximum pressure of the water squirting out is dependent on the level of water in the tub. Ideally, there should be more water coming into the tub than will be ever drawn to ensure that the pressure of the water coming out of the hole is constant. This means that a fair amount of water will spill over the edge of the tub. As was shown in the previous section, this is an extremely inefficient method of providing a regulated voltage, as the electrical equivalent of the water pouring over the edge is the power dissipated by R.

To improve upon the zener diode regulator’s inefficiency, a voltage regulator that just lets out enough current at the regulated voltage is desired. The linear voltage regulator only allows the required current (at the desired voltage) out and works just like a car’s
carburettor. In a carburettor, fuel is allowed to flow as required by the engine—if less is required than is available; a valve closes and reduces the amount of fuel that is passed to the engine. The linear voltage regulator works in an identical fashion: an output transistor in the regulator circuit only allows the required amount of current to the load circuit. The actual circuitry that implements the linear regulator is quite complex.
One but not least Most important Equipment of Electronic and Robotic and Brain of a Bot-Microcontroller.
8. The Microcontroller
A microcontroller (or a microprocessor) is a device which receives the signal given by the sensors and processes it. A microcontroller has a predefined set of conditions and corresponding actions to be taken for each of them.

If voltage given by sensor is (conditions) Do the following (Instructions)
Less than 3 volts Give 5 volt at the output
equal to 3 volts Give 6 volt at the output
Greater than 3 volts Give 7 volt at the output
Processing a signal essentially means checking that with which condition does the input matches. For example, if the input given by the sensors to the microcontroller is 2 V, the microcontroller will immediately provide 5 volt at its output. Many vendors manufacture microcontrollers.

The most popular products and their vendors are given below:
1. PIc Developed by microchip
PIc16F84 has been a one of the favorites of hobbyists.
2. aVr Developed by atmel.
       3. H8 Developed by Hitachi.
       4. 8051 Developed by Intel (this is the oldest and base of all microcontrollers and I also recommend this for beginners).
All of the above mentioned vendors provide excellent support in terms of software and all the above mentioned devices can be used with ease once you get acquainted with them.