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0answers
36 views

Implementing a boolean function using decoder and or gates

I am trying to implement the negation of a set of minterms. As a result my function looks something like: \$(A+\bar{B}+C)(\bar{A}+\bar{B}+C)(\bar{A}+\bar{B}+\bar{C})\$ I know how to implement it if ...
0
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3answers
99 views

How to make 7-segment display count up ?

I've connect 7447 decoder and 74193 counter as shown in the picture but I have not used 555 timer yet. Is there any way to test the circuit before using 555 ? I've connected the pins (up and down) ...
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3answers
70 views

Switch between two digital signals with no microcontroller

I'd like to use an Arduino to send wirelessy (RF 433MHz, probably) two different digital signals to pilot two different relays (later they will be much more). I know probably this is something very ...
0
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2answers
85 views

How to connect 7447 decoder to 7-segment display?

I've connected a 7447 decoder to 7-segment display as shown in figure. When I connect an input, the LEDs doesn't form numbers but they light up randomly. I just want to know the right way to ...
0
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2answers
53 views

Signal-driven 3 output logic gate decoder or switch?

I need to build a simple logic gate circuit such that when a single input signal or switch goes low it alternately activates one of three outputs as high. That is, every time it goes low the currently ...
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3answers
91 views

State Machine w/ Decoder

I'm trying to design a State Machine that acts as a synchronous lock. There is only 1 input (X) and one output (Lock= 0, Unlock = 5v). The machine will only unlock if the following order is put in: 0* ...
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1answer
51 views

G.711 for dummies

I am in midst of some online telephony course, and there are questions regarding which I have no one to ask but this community. G.711 volume encoding. I have some difficulty to understand how ...
0
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1answer
46 views

Finding the minimum switching expression for this output

Did I do this correctly? ...
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3answers
213 views

74154 4 to 16 decoder logic diagram

Will someone please explain the purpose of inverting the outputs (0 through 15) as well as the use the NAND gates here? 2nd, less important question: why are there two input G1 and G2 if the ...
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2answers
126 views

An exercise on decoders

I have the following exercise: Design a circuit that takes a 2 bit binary and makes it x^3 (x cubed), using a decoder of your choice. I thought to do it with a ...
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3answers
102 views

Why almost all decoder zero selected output?

I have decoder IC 74138 and I found almost all decoder make selected output low (0) and I want it high (1) and I don't want to connect NOT gate to all of the outputs (it is illogical). What should I ...
0
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0answers
50 views

How to create a 4 to 16 rom with basic (AND,OR,NOT,log 1/0) gates

I want to create a read only memory with the basic (and, or not) gates. The 4 to 16 decoder will be used to tell the rom which line / adress should be used. Normaly a ROM is programed by setting ...
0
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0answers
156 views

How to design a 6-64 bit decoder using two 3x8 line decoders and AND gate?

gate? please help me in constructing this circuit. I dont know how to use and gate for constructing this circuit.
0
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1answer
137 views

Decode an infrared signal with an IR demodulator inside a microphone jack

I was looking at this tutorial about how to decode an infrared signal. One of the posts says For the scoped challenged (like me), a PC microphone jack works great for reverse engineering IR ...
0
votes
1answer
66 views

Is it feasible to decode an 15 kHz RGB (SCART) signal using a sound card?

Do you know whether it would be feasible to decode an 15 kHz RGB signal (from a video game console) using a sound card ? Providing such input can be captured finely enough by a 192 kHz sound card, ...
0
votes
1answer
78 views

Implementing a function with 4 inputs with 2x4 decoders

I'm a bit confused on how it is done. In the pdf we were given it only showed the solution, no explanation whatsoever. My guess is in order to implement 4 inputs with 2 input decoders, the decoder ...
0
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1answer
134 views

How to connect 3-digit display and suppress leading zeroes?

I searched a little and it told me to use with more than one display, connect (Ripple Blanking Output) from most significant 7447 to the of the next 7447. Which number would be most significant? ...
5
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1answer
74 views

7-Segment Decoder outputs/LED display

What would be the difference in using a 7-segment decoder with active-high outputs vs active-low outputs, to driver an LED display?
3
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3answers
206 views

Increase GPIO outputs

I'm working on a project in which I need 32 outputs from an MCU that only has 8 free outputs. To accomplish my goal I have the following requirements: I must be able to toggle more than one output ...
0
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0answers
68 views

How to decode the hall-effect sequence from a motor?

I have a motor running in open loop (voltage controlled PWM/ freq.) and am reading the values of the 3 hall-effect sensors via UART. Ideally, I thought the data would show 6 commutation states with 6 ...
2
votes
1answer
766 views

RF Module Not Working

I'm working on RF Module(433MHz ) for Communication between Robot and controller. So I want to test this first. Here is the thing I've used two Encoders Named HT12E and HT12D which are WORKING Fine ...
0
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1answer
88 views

Building memory system adresses with decoders

Well I got the following (multiple choice) question. Even with the result given I have 0 idea how they could come to the conclusion.. With 64 memory elements of size 1Mx4 and several 2-input ...
0
votes
1answer
334 views

Implement a Function using 3x8 decoder (74LS138)

I need to implement the function below using 3x8 decoder (74LS138) and a minimum number of gates but I did not see 74LS138 before. F = (A.B)' I implement the function using a normal 3x8 decoder but ...
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1answer
541 views

Can I use this rf module with HT12E and HT12D?

I have recently made RC car using HT12E and HT12D connected to a cheap ASK RF module of 433 MHz frequency,but it's range is not good only a few meters and also so prone to electrical noise generated ...
1
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1answer
86 views

Using a Line Decoder (Multiplexer) to set multiple outputs high

When using a 3-to-8 Line Decoder / Multiplexer such as the 74HC238, can I set multiple outputs (1-8) as high at the same time? As opposed to only one output high at any given time, and the rest are ...
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2answers
250 views

Pin Arrangement which one should i follow?

I have 2 different arrangement of 7448 IC's pins, and I'm not sure which one I should follow. The two different pin arrangements I found for the IC are: ...
1
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1answer
1k views

Finding the no. of decoders required in cascading

I am trying to solve the following question. How many 3 to 8 decoders with an enable input are needed to construct a 6 to 64 line decoder without using any other logic gate. I have a Digital ...
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1answer
2k views

Design a 4:1 MUX by three 2:1 MUX or by 2:4 decoder? [closed]

A 4:1 MUX can be built by using three 2:1 MUX. But I've not done it this way: I've used a 2:4 decoder to make a 4:1 MUX. Does it matter?
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3answers
368 views

How can I store audio files in the uC ROM so as to serially transmit it to a decoder chip?

I am using an NXP micro controller (P89V51RD2) with on board flash of 64kB. I want to interface it with an audio decoder IC, probably VS1011 (if I can get the IC). What should I do to use on board ROM ...
4
votes
1answer
175 views

How large is the address decoder to select an address in RAM? Is the address decoder just a bunch of multiplexers?

I have recently started building simple computing devices using logic gates inside of Minecraft. What I'm trying to build right now is some RAM, and an address decoder for this RAM. I want to build a ...
1
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0answers
282 views

Forward Error Correction code, Reed Solomon, Turbo Code, Low-density parity-check

I am new to FEC (Forward Error Correction). Pointers highly appreciated. I am experimenting software with configurable "error protections". Result improving as setting raise to 40%. Still not ...
0
votes
2answers
8k views

How to build a 4 to 16 decoder using ONLY TWO 2 to 4 decoders?

Help please, I am new to circuits and decoders and I need some serious help. How to build a 4x16 decoder using ONLY two 2x4 decoders? Following the steps we took in the lecture, we are supposed to ...
2
votes
1answer
377 views

DVI-D Single Link to FPGA

I'm using LatticeXP2 family FPGA. DVI-D Single link operating at 720p is connected to FPGA. I somehow need to read RGB and XY coordinates of pixels. I know I need TMDS decoder, but I'm not sure how to ...
2
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1answer
477 views

IN-12A Nixie Tubes and K155ID1 (74141 clone) Power

I'm working on a design with some Nixie tubes (a clock, specifically to start, but I'm gonna have a ton left over for other things), and due to the rather expensive nature of the K155ID1/74141 ICs, ...
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2answers
4k views

Implementing 4-to-16 decoder using 3-to-8 and 2-to-4

This is digital logic question. I think it's alright to post it here. I'm trying to implement a 4 to 16 decoder using 2 to 4 decoder and 3 to 8 decoder. What I did, I used 2x of 2-to-4 decoder and ...
1
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2answers
2k views

Manchester Decoding

Is a Phase Locked Loop compulsory for decoding Manchester encoded data? Is the PLL used so that Manchester encoding supports different data rates? useful links: ...
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4answers
1k views

How to decode morse code with digital logic

I have been curious as to how one might implement a morse code decoder with basic digital logic (no microcontroller), mostly as an exercise. I could decode individual letters with a state machine, if ...
3
votes
1answer
232 views

An IC that would combine a counter and a decoder

I have a circuit that makes uses of a decoder to command the latch line of 8 latches. To avoid spurious latching that could occur in transitions, I disable the decoder output while I change the input ...