So, there are four product terms in total. The circuit diagram of 2 to 4 decoder is shown in the following figure. If enable, E is zero, then all the outputs of decoder will be equal to zero. Implementation of Higher-order Decoders Now, let us implement the following two higher-order decoders using lower-order decoders. We can find the number of lower order decoders required for implementing higher order decoder using the following formula.

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These are frequently used in communication system such as telecommunication, networking, etc.. Similarly, in the digital domain, for easy transmission of data, it is often encrypted or placed within codes, and then transmitted. At the receiver, the coded data is decrypted or gathered from the code and is processed in order to be displayed or given to the load accordingly. It has a number of input lines, but only one of the inputs is activated at a given time and produces an N-bit output code that depends on the activated input.

The encoders and decoders are used in many electronics projects to compress the multiple number of inputs into smaller number of outputs. The encoder allows 2 power N inputs and generates N-number of outputs. For example, in encoder, if we give 4 inputs it produces only 2 outputs. There are different types of encoders and decoders like 4 , 8, and 16 encoders and the truth table of encoder depends upon a particular encoder chosen by the user.

Here, a 4-bit encoder is being explained along with the truth table. The four-bit encoder allows only four inputs such as A0, A1, A2, A3 and generates the two outputs F0, F1, as shown in below diagram.

Simple Encoder Encoder Truth Table Priority Encoder A normal encoder has a number of input lines amongst which only one of which is activated at a given time while a priority encoder has more than one input, which is activated based on priority.

Which means that, the priority encoders are used to control interrupt requests by acting according to the highest priority request? If two or more inputs are equal to one — at the same time, the input having the highest priority will be preferred to take. Internal hardware will check this condition and priority, which is set. Priority Encoder Multiplexer The multiplexers and demultiplexers are digitalelectronic devices that are usedto control applications.

A multiplexer is a device that allows multiple input signals and produces a single output signal. For example, sometimes we need to produce a single output from multiple input lines. Electronic multiplexer can be considered as a multiple input and single output lines.

In this case, the multiplexer used selects the input line to be sent to the output. The digital code is applied to the selected inputs to generate respective output. Each device in succession has a brief time to send and receive the data. This is the special advantage of using this MUX.

Multiplexer Introduction Of Decoder The decoder is an electronic device that is used to convert digital signal to an analogue signal. It allows single input line and produces multiple output lines. The decoders are used in many communication projects that are used to communicate between two devices. The decoder allows N- inputs and generates 2 power N-numbers of outputs. For example, if we give 2 inputs that will produce 4 outputs by using 4 by 2 decoder.

There are different types of decoders like 4, 8, and 16 decoders and the truth table of decoder depends upon a particular decoder chosen by the user. The subsequent description is about a 4-bit decoder and its truth table.

The four bit decoder allows only four outputs such as A0, A1, A2, A3 and generates two outputs F0, F1, as shown in the below diagram. As you can see in the truth table — for each input combination, one output line is activated. Thus, each output of the decoder will be generated to the input combination. As you can see in the truth table, for each input combination, one output line is activated. For example, an input will activate the line A0, A1, A3 as 01 at the input has activated line D1, and so on.

As represented by the truth table, only one output can be equal to zero at any given time, all other outputs being equal to one. The outputs represent minterm selected by the inputs A1 and A0. If the circuit is disabled, then none of the outputs are equal to zero.

This project is applicable to many industries like steel plants, paper plants and textile mills, where the motors are used to design simultaneously. All these motors used on conveyer are designed to be synchronized. Speed Synchronization of Multiple Motors in Industries In this system, one motor output is given as the reference speed for the other motors to follow same speed. The proposed system consists of two blocks: transmitter and receiver blocks, which are built with encoder and decoder.

A particular speed is sent by the transmitter with the help of the decoder. The receiver receives the data and converts the digital format to send the receiver system, and maintains same speed as it has received. Thus, if a particular speed is set by the transmitter, then other motors run with the same speed by utilizing radio-frequency communication.

This kind of robot can be helpful for spying in War fields. War Field Flying Robort with NJight Vision Flying Camera In the transmitting end push buttons are used; commands are sent to the controller for controlling the movement of the robot either in forward, backward, left, right, directions.

The RF transmitter acts as a RF remote control that has the advantage of adequate range up to meters with proper antenna, while the receiver decodes before feeding it to another microcontroller to drive DC motors via motor-driver IC for necessary work. A wireless camera is mounted on the robot body for spying purposes, even in complete darkness by using infrared lighting. The basic schematic diagram is shown above.

The robot is controlled by a remote using RF technology. At the transmitting end, using push buttons, commands are sent to the receiver to control the movement of the robot either in forward, backward and left or right directions. At the receiving end, two motors are interfaced to the microcontroller where they are used for the movement of the vehicle. Robotic Vehicle with Metal Detector The RF transmitter acts as a RF remote control that has the advantage of adequate range up to meters with proper antenna, while the receiver decodes before feeding it to another microcontroller to drive DC motors via motor driver IC for necessary work.

As technology is advancing so houses are also getting smarter. Modern houses are gradually shifting from conventional switches to a centralized control system, involving RF controlled switches.

RF based Home Automation System Presently, conventional wall switches located in different parts of the house make it difficult for the user to approach them for operations. Remote controlled home automation system provides a simpler solution with RF technology. It is a very tedious method. The message is retrieved at the receiver end only upon entering the secret code used by the transmitter.

Thus, complete secrecy is maintained in this communication process. This project has a unique feature of tagging the message with a secret code as selected by the sender. The message is then transmitted through the RF transmitting module. At the receiver end, the signal is received by the RF receiver module.

The message is then retrieved only if the secret code is known to the receiving personnel. In this project, the encoders and decoders are used to transmit and receive the information. Once the secret code is entered, then message is displayed on the receiving unit on the LCD display. Related Posts:.


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