Questions tagged [multiplexer]

A multiplexer selects one of two (or more) inputs based on a control input. It then outputs the selected input.

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95 views

Sharing a USB keyboard between two PCs on a button flip

The PCB for the task would comprise of a USB connector, two sets of 4 PTH for the two USB cables (one set towards PC 1, the other towards PC 2), shared GND and TX and a DPDT switch for separating the ...
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43 views

Can one (or 2 connected) multiplexer control 10 other multiplexers?

I'm in my infancy with electronics. I took a course in college way back before a lot of you were born (30 years ago). So, forgive my ignorance if the question is somewhat trivial. I've got an idea ...
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208 views

How to create 1:4 Demux diagram using 1:2 Demux?

By 2m = n where m is the number of select lines and n equals the number of outputs (4) I found that I will need 2 select lines in total. But, I don't even know how to start drawing the actual circuit ...
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215 views

What is the minimum number of 2-to-1 muxes needed to implement a 129-to-1 mux?

I understand that if the requirement was to implement a mux that was a power of two there is the trick where you can do do x -1, so for instance if I wanted to implement a 8-to-1 mux, I would use 7 ...
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1answer
83 views

How to design a multiplier using only multiplexer?

I am asked to make a multipier that takes a three bits input $$x=(x_1, x_2,x_3)$$ and a control signal \$s\$ so that the results will be a hexadecimal 4 bit number $$z=(z_3,z_2,z_1,z_0)$$ such that \$...
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42 views

Pcf8574ap to to manage the 4 address pins of 4067 multiplexer?

I have a question. I have a 4067 multiplexer connected to my Raspberry Pi, 4 GPIOs turned on or off, control the channel of the multiplexer. My problem is that if no channel is changed, my code is ...
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2answers
147 views

Where are all the multiplexers?

I am trying to implement a circuit where 2 SPI drives (basically two masters) speak to 1 slave. Both operate on a 3 wire SPI. Keeping that in mind I was going to have the CLK and MOSI of both as ...
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1answer
258 views

Logic Design simple door security system with using MUX

I draw the cicuit without using any MUX. But my project says I need to use 4x1 MUXs and I couldn't find where to use 4x1 MUXs. I tried put MUX of each output but this was very pointless, no need to ...
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1answer
745 views

8:1 multiplexer to 6:1 multiplexer

I have 6 inputs that I want to insert in a 8-1 multiplexer. I just want to know how to modify the 8-1 mux to support only 6 inputs. I mean the last two rows on the truth table of the 8-1 won't be ...
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1answer
90 views

Questions About BJTs in My Circuit

I have an LED multiplexer circuit (inspired by https://www.instructables.com/id/Multiplexing-with-Arduino-Transistors-I-made/) in which I have set the resistor values to maximize the current through ...
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2answers
39 views

Multiplexer diagram of \$C = A \cdot B\$

I'm having some trouble figuring out how to illustrate, as a diagram, a multiplexer. I realise that a multiplexer takes in a number of input signals and depending on the control sign, outputs the ...
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2answers
64 views

Is there a demux IC that allows a default signal (not just digital 0) to go to the non enabled outputs?

I am trying to control multiple servos using a Demux and I want the selected output to have one pwm signal and then all of the non selected outputs to receive the same default pwm signal instead of a ...
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1answer
73 views

Matrix “Multiplexing” with electromagnets, interesting behaviour

I have an interesting behaviour with my electronics project. I am trying to do something like a LED array but with electromagnets instead. See the schematic below. I built the magnets myself by ...
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1answer
49 views

How to choose which function to use depending on the parameter value? (MUX and Gates implementation)

Let's say we have A,B,C , which are all representation of decimal numbers. A and C are 4bit, B is 2bit. if A is any of those numbers (eg: 0,5,6,11 ), the function is F(A,B,C) = AB+C If A is the ...
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427 views

Difference between multiplexer and decoder

What is the difference between a multiplexer and a decoder? Lets assume a 2-to-4 decoder and a 4-to-1 multiplexer, what I understand is they both select one input based on the selector's combination. ...
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2answers
208 views

Switching a current source through a MUX

I have a current source of square pulses (0-20 uA) generated by a NI 9265 device. I am trying to build a fast switching circuit using TI CD4051 multiplexer to switch the current signal between ...
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636 views

Implementing analog multiplexers in LTSpice and Cadence Virtuoso

Is there any model for Analog Multiplexer compatible with LTSpice or Cadence Virtuoso? A simple 2:1 multiplexer is implemented in LTSpice as a SPDT switch. So how to implement a 4:1, 8:1 or 16:1 ...
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1answer
72 views

Is Multiplexing Fast Charger Safe? [closed]

I got a original Samsung 2A output phone charger. If I open inside and add some wires and USB port to the circuit board and try to charge 2 devices in same time, what happens? Is it safe? Can I get ...
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1answer
110 views

Flashing multi chips with JTAG using openocd

I'm newbie in this field. My task is I have to flash 6 devices with JTAG like the picture below. I'm currently success with flashing one device. Can someone give me advice how to flash all 6 devices? ...
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1answer
111 views

Make a circuit that indicates an odd number of ones using a 3-8 Demux and two logic gates

Using 3-8 Demux and two logic gates, make a circuit that received 4 bits and returns 1 if the number of 1's is odd and else returns 0. My try: Using truth table, we get that the desired function is: ...
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400 views

Variable input MUX in Verilog

What's the best way to make an N:1 multiplexer in Verilog (NOT SystemVerilog), where the maximum N is 64? Each input is 32-bits wide and there are N such inputs. Verilog doesn't allow two-dimensional ...
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1answer
187 views

Why can't I implement a frequency divider using a mux in this way?

I found an interesting interview question for FPGA engineer online - Implement a counter with Mux, so I decided to try to do that. I tried to keep it simple and so implement a counter with two bits, ...
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52 views

Question on output of an FPGA

I have been trying to solve this basic FPGA problem with multiplexers, but I cannot garner the meaning of the notation 0/1. Can someone throw some light in this regard? What do notations like 0/1 mean?...
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1answer
103 views

Anode scanning Nixie circuit

I'm looking into driving nixies and i came across this multiplexing circuit I am a little bit confused about the chosen voltages. The 200v line I would assume is to meet the required strike voltage, ...
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1answer
35 views

utilize a single channel to transmit data generated from 16 users (using mux)

I have found this question in a book and find it confusing. The question is, For a communication system, it is required to utilize a single channel to transmit the data generated from 16 users. ...
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3answers
748 views

Multiplexing vs shift registers (input)

I'm going to use a microcontroller to read 80 digital inputs (push button switches). I'm wondering (just to understand, I don't have any critical time constraint) if it would take less time using ...
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1answer
40 views

Upto how much voltage can be multiplexed by 4051B 8X1 IC?

I want to control a 9 volt pump with my arduino, and my arduino is giving around 2V as output through its gio pins ( I don't know exactly the reason why, maybe cause I have lots of other sensors ...
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2answers
93 views

What is this kind of “Multiplexer” called?

First of all I am new to electronics so i might use wrong terms. What is this electronic component called or is it even a thing (Can it be bought)? I have 10 input wires/channels for example. Only ...
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3answers
323 views

Not enough pins, looking for a “demultiplexer” that keeps state [closed]

I want to control a simple display with a microcontroller. The display has 8 input pins, the microcontroller only 6. Is there an IC that I can interpose that lets me set the state of each of its ...
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1answer
73 views

circuit that disconnects a connection

I'm designing a circuit that will disconnect a connection when 5 consecutive square wave pulses are missing. If less than 5 consecutive pulses are missing then I want to reset the counting process. <...
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1answer
171 views

How to use multiplexor 74HC4067

I am using 74hc4067 IC(Multiplexer 4:16) for the extend the gpio pins can i use that gpio pins same time or not? and any one suggest about the ic how it is used?
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116 views

What is the best way to step my signal from 5V to 3V3? [duplicate]

I have some analogue signals between 0 and 5 Volts being fed from a multiplexer into another board that only accepts signals up to 3v3. What is the best way to step down the voltage? The signal ...
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3answers
288 views

Creating a two input two way digital switch [closed]

I'm very much a beginner here, so bear with me. I'm looking to create a digitally controlled switch that has two inputs and two outputs. (Update: The signals are 0V-1V analog.) Here are the two ...
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3answers
99 views

Decade voltage divider switching

I have a decade voltage divider used for range switching in my project. I need a way to switch the multiple different voltages that the divider creates into one output, sort of like a multiplexer ...
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2answers
64 views

Can a MOSFET generated high voltage (315v) pulse train be measured using a DMM in AC mode?

I am using a 5V pulse train generated from a UC3845 PWM controller to trigger a MOSFET (K2645) which is biased with 317VDC in series with Rd= 120ohms, Rs=20ohms and primary of the PWM transformer. I ...
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2answers
256 views

Controlling Power LEDs through multiplexer

I'm working on a circuit to control some number of 1W Power LEDs with Arduino. I used the constant current driver with MOSFET from here: http://www.pcbheaven.com/userpages/...
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133 views

Switch a differential I²C bus section, controlled via I²C

I want to separate a section of an I²C bus, controlled via an I²C message. (Similar to an I²C bus switch/multiplexer like e.g. PCA9540.) Indeed the I²C bus to switch isn't a plain vanilla I²C bus, ...
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1k views

Switching RS-485 bus

As shown in the graph, I'm trying to use mcu-controlled switches to turn a segment of rs-485 bus on or off (so that only one segment is on at a time). I was considering analog switches but I'm not ...
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1answer
67 views

the minimum size of the multiplexer needed?

Suppose only one multiplexer and one inverter are allowed to be used to implement any Boolean function of n variables. What is the minimum size of the multiplexer needed? answer is- 2^(n−1) to 1 ====...
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1answer
73 views

Is it Possible to control LED with arudino pins combined with PWM from IC?

What I'm looking to make is a multiplexed 16x16 LED grid with with 2-bits of brightness (aka 4 levels of brightness). There might be a better way to do this. I've built a prototype 8x8 grid with an ...
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3answers
251 views

Multiple I²C slaves with different addresses VS. using a multiplexer

I'd like to interface a lot of identical I²C sensors, let's say 32, with a MCU that has only 2 I²C busses. I can configure each sensor to have up to 8 different addresses. Hence I can have 8 sensors ...
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1answer
94 views

IVPort raspberry pi camera module

Im trying to design multiplex camera system for my raspberry pi something like this https://www.tindie.com/products/canerdurmusoglu/ivport-dual-v2-raspberry-pi-camera-multiplexer/#product-description ...
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2answers
335 views

Pulldown to prevent floating input pins for multiplexer

I'm designing a multiplexer shield for Arduino, by which it will (hopefully be possible to read up to 64 analog inputs such as potentiometers etc.. Schematics of rev.0.1 can be found here. I'm using ...
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1answer
74 views

Digital Logic Question involving Muxs

I'm having trouble understanding the solution to this digital circuit problem involving muxes. Could anybody explain how they got to this answer.
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1answer
244 views

Channel Bleeding with ADG732

I'm building a circuit that uses a 32:1 mux (ADG732) to feed the selected channel into an amplifying stage so I only need one amplifying circuit. The input signals are from pressure sensors which have ...
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1answer
21 views

SHorting MIPI Mux lines

I am currenty using the TS5MP646 http://www.ti.com/product/TS5MP646 . I need to build a 4:1 mux. I was wondering if I need to use 3 muxes, or can i just short the MIPI traces together and control it ...
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202 views

Multiplexing battery voltages with high precision

I would like to multiplex battery voltages used for impedance measurements. The battery cells are not connected. My idea is to have one multiplexer chip for the positive poles, and one chip for the ...
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83 views

Power mux (TPS2115A) has a huge voltage loss?

I have a MCU which I need to be powered up after a power failure for a few seconds - super capacitors are too large for this application - I wanted to use a power mux (TPS2115A) to switch to a battery ...
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2answers
54 views

Connecting mixed-speed multiple serial devices to two microcontrollers

I'm trying to figure out the best way to integrate all devices flawlessly on the 8051 based microcontrollers. If each device was the same low speed, then I could multiplex each and every one of them ...
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2answers
340 views

ESP8266 I2C Multiplexer

EDIT: I ran an i2c bus scanning program and it detected a device at 0x70 (the mux). I connected the device I am trying to interface with directly to the i2c bus and ran this code and it worked ...