Category: Elect. & Comm.

VHDL code for D-Flip Flop


1.VHDL code for 2 to 4 binary decoder

2.VHDL code for 4 bit comparator



Here is the VHDL coding of the d-flip flop :

LIBRARY ieee ;

USE ieee.std_logic_1164.all ;

ENTITY flipflop IS
PORT (     D, Resetn, Clock     : IN     STD_LOGIC ;
Q                     : OUT     STD_LOGIC) ;
END flipflop ;

ARCHITECTURE Behavior OF flipflop IS
WAIT UNTIL Clock’EVENT AND Clock = ‘1’ ;
IF Resetn = ‘0’ THEN
Q <= ‘0’ ;
Q <= D ;
END Behavior ;


Well be updated with the overgrowing advanced topics of engineering from all IT,CS,Mech. etc.

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# Green Engines

# Nano Robotics

# Mobile Ad Hoc Network(MANET)

# Common Rail Direct Injection (CRDI) engines

# Microprocessor Based IC Engines

# 5-axes Machining

# Robotics, Dynamics and Control

# Automation in Automobiles

# Software Development ( Application of Software in Renovating India)

# Green IT Strategy (Conserving Energy, Reducing Carbon footprint of a Company, Limiting Waste)

# Astrophysics

# Smart Materials

# Fiber Sensor

# Foreign Direct Investment(FDI)

# Fiscal Policies

# Union Budgets

# SWOT Analysis

# E-Commerce

# Cognitive Radio Design

# 3D photography

# Airbourne Vehicle Communication

# Agent OS

# Latest trends in SuperConductivity

# Cloud Computing

# Hardware and Software for Low Power

# Grid Computing

# Cryptography

# Green Power: Alternate Energy Sources

# Soft Computing Techniques: Microprocessor $ their application, Robotics $ Automation, Fuzzy Control Techniques

# FACTS(Flexible AC Transmission System)

# Quantum Electronics

# Biometric Authentication

# Brain fingerprinting

For more details over any topic please write us here,we will soon try to update over it.

Below is the list of microcontroller based major projects,futher they can be modified too for further enhancement:
1. Artificial intelligent solar power generation

2. A testing method for PIR detectors system

3. A mobile – agent based distributed intelligent control system architecture for
home automation

4. A multi agent multi sensor based security system for intelligent building

5. Industrial energy saver

6. A novel optimum point tracker of the solar cell power supply system

7. Train collision detection

8. Humidity monitoring and pumping system

9. Alcohol detection with vehicle controlling

10. Automated restaurant for efficient maintenance

11. RF based human movement monitoring

12. Smoke alert system for industries

13. Intelligent guard alert system

14. Auto-image monitoring using CCTV camera

15. Path planning system for blind

16. Digital energy meter with auto limiting of load

17. Intelligent fire detection and fighting robot

18. Temperature level monitoring and automatic control in boiler

19. Self guided vehicle

20. Automated conveyor system

21. Modern car parking system

22. Ozone gas generator for water purifier

23. Aeronautical collision prevention system

24. Automated bus-stop alert for passengers

25. Bus identification system for blind

26. Eye blink with more explanation

27. Wireless motor control system

28. Chopper based dc motor controller

29. PWM based solar tracking system with sine wave inverter

30. PWM based single phase ac induction motor with close loop controller

31. PWM based three phase ac induction motor with close loop controller

32. Single axis solar panel tracking system

33. Double axis solar panel tracking system

34. Solar based lighting system

35. Solar agro sprayer

36. Coil winding machine

For further information over any project,write us here,soon we will try to update over it.








Well below is the VHDL coding of a 2 to 4 binary decoder:

LIBRARY ieee ;
USE ieee.std_logic_1164.all ;
ENTITY dec2to4 IS
END dec2to4 ;
ARCHITECTURE Behavior OF dec2to4 IS
Enw <= En & w ;
y <= “1000” WHEN “100”,
“0100” WHEN “101”,
“0010” WHEN “110”,
“0001” WHEN “111”,
“0000” WHEN OTHERS ;
END Behavior ;

VHDL Code for 4 Bit Comparator

4 bit comparator








The vhdl coding for a 4 bit comparator is as follows:-

Its a behavioural type of modelling…..

LIBRARY ieee ;
USE ieee.std_logic_1164.all ;
USE ieee.std_logic_arith.all ;
ENTITY compare IS
AeqB, AgtB, AltB : OUT STD_LOGIC ) ;
END compare ;
ARCHITECTURE Behavior OF compare IS
AeqB <= ‘1’ WHEN A = B ELSE ‘0’ ;
AgtB <= ‘1’ WHEN A > B ELSE ‘0’ ;
AltB <= ‘1’ WHEN A < B ELSE ‘0’ ;
END Behavior ;


Automatic Metering Using 3G Technology

Automatic Metering Using 3GAutomatic Metering Using 3G-a new booming topic to the upcoming technology i.e. 3G.The things which has enhanced its properties over simple metering are:

1.Use of 3g.

2.Wireless connectivity with high security.

3.Automatic,so as to reduce human headache and error cases.


Below is the further description of each and every part with their figures:

automatic metering by 3g

Theses are the gas ,water and electric meters but specially equipped with 3g systems so as they can convert and then Emmit the units covered into the collectible data packets.


automatic metering by 3gThese are the 3g boosters which will collect all the emitted data packets from meters and also boost its quality as suggested by its name then the collected data will be transferred to the repeaters.






automatic metering by 3gRepeaters are simply the large boosters.All the data packets from various boosters are collected by the repeaters and is sent for data management after its decoding.






automatic metering by 3gFinally data is managed through advanced scheme by graphs and charts for decoding the data packets into the units again and then bills are formed to be posted to consumers.






That”s all about automatic metering by 3g,please give your comments over it and feel free to ask any query in any case.

If you need a presentation over it , please write me,i will surely try to post it here.

Variable Regulated Power Supply:Project

Variable Regulated Power Supply The project “VARIABLE REGULATED POWER SUPPLY” plays a very important role in the laboratory functions and that is mainly to the electronics labs. As in electronics all the instruments, components work on a particular regulated dc supply ,so a project which can provide this supply by converting the alternating current to direct current that too into a great range of regulated power keep its own preference. As it can produce a range of 0-30 v direct current by regulating and converting alternating current is has a vast application too. Such converters are also known as “Switch Mode Power Supply” (SMPS). AC to DC converters generally comprise a rectifier bridge to rectify the AC current of the input line and a regulating device supplying on output of one or more regulated DC voltages.

Just the simple ac current is applied and through potentiometer you get the desired regulated dc power supply.

Variable Regulated power Supply

Following is the list of parts or the components required to design this circuit:

1.      BR1 = Bridge Rectifier, 100V – 3A

2.      C1 = 2200 µF, 63V

3.      IC1 = LM317, adjustable regulator

4.      C2 = 0.1 µF

5.      V = Meter, 30V, Ri = 85 ohm

6.      C3 = 1µF, 40V

7.      TR1 = Transformer, 25V, 2A

8.      Plug = 3-wire plug & cord

9.      R1 = 18K, 5%

10.  S1 = On-Off toggle switch

11.  R2 = 220 ohm, 5%

12.  D1 = 1N4001

13.  R3 = 27K, 5%

14.  Fuse = 110V, 500mA, slow-blow

15.  P1 = 5K, potentiometer

16.  P2 = 10K, 10-turn trim-pot

17.  Fuse Holder, wire, solder, case, knob for P1

18.  Red & Black Banana Jacks


The 110V-AC coming from the powercord is fed to the transformer TR1 via the on-off switch and the 500mA fuse. The 30v ac output (approximately) from the transformer is presented to the BR1, the bridge-rectifier, and here rectified from AC (Alternating Current) to DC (Direct Current). If you don’t want to spend the money for a Bridge Rectifier, you can easily use four general purpose 1N4004 diodes. The pulsating DC output is filtered via the 2200µF capacitor (to make it more manageable for the regulator) and fed to ‘IN’-put of the adjustable LM317 regulator (IC1). The output of this regulator is your adjustable voltage of 1.2 to 30 volts varied via the ‘Adj’ pin and the 5K pot meter P1. The large value of C1 makes for a good, low ripple output voltage.
Why exactly 1.2V and not 0-volt? Very basic, the job of the regulator is two-fold; first, it compares the output voltage to an internal reference and controls the output voltage so that it remains constant, and second, it provides a method for adjusting the output voltage to the level you want by using a potentiometer. Internally the regulator uses a zener diode to provide a fixed reference voltage of 1.2 volt across the external resistor R2. (This resistor is usually around 240 ohms, but 220 ohms will work fine

without any problems). Because of this the voltage at the output can never decrease below 1.2 volts, but as the potentiometer (P1) increases in resistance the voltage across it, due to current from the regulator plus current from R2, its voltage increases. This increases the output voltage.
D1 is a general purpose 1N4001 diode, used as a feedback blocker. It steers any current that might be coming from the device under power around the regulator to prevent the regulator from being damaged. Such reverse currents usually occur when devices are powered down.
The ‘ON’ Led will be lit via the 18K resistor R1. The current through the led will be between 12 – 20mA @ 2V depending on the type and color Led you are using. C2 is a 0.1µF (100nF) decoupler capacitor to filter out the transient noise which can be induced into the supply by stray magnetic fields. Under normal conditions this capacitor is only required if the regulator is far away from the filter cap, but I added it anyway. C3 improves transient response. This means that while the regulator may perform perfectly at DC and at low frequencies, (regulating the voltage regardless of the load current), at higher frequencies it may be less effective. Adding this 1 µF capacitor should improve the response at those frequencies.
R3 and the trimmer pot (P2) allows you to ‘zero’ your meter to a set voltage. The meter is a 30Volt type with an internal resistance of 85 ohms. I you have or obtained a meter with a different Ri (internal resistance) you will have to adjust R3 to keep the current of meter to 1mA. Just another note in regards this meter, use the reading as a guideline. The reading may or may not be off by about 0.75volts at full scale, meaning if your meter indicates 30 volts it may be in reality almost 31 volts or 29 volts. If you need a more precise voltage, then use your multimeter.