A multiplexer selects one of two (or more) inputs based on a control input. It then outputs the selected input.
2
votes
1answer
41 views
What would the firmware to control Shift1 system (for 1-pin shift register operation) look like?
This is a follow on question from this answer by Spehro Pefhany, in which he explains to us how to use 74HC595 serial shift registers with only one digital output pin. Below's the picture he posted.
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3
votes
2answers
113 views
How to “deserialize” a digital output to 4 digital outputs
I am working on a small test project for my Arduino and as part of it, I want to display a number on a 7-segment LED system. My first setup involved just direct links to the 7-segment display and ...
4
votes
1answer
166 views
Why two inverters cascaded in multiplexer control signal terminals?
Why cascaded inverters are used in the multiplexer when it is possible to realize the circuit using a single inverter.
-3
votes
0answers
27 views
Mux has (n) inputs and (n sel.) line
I need to implement with vhdl a mux that has (n) inputs and (n) sel. line.
So lets say my numbers are A, B, C and D. When the index number is (0) I would like to have A as an output, when the index ...
0
votes
2answers
61 views
Select channel from multiplexer to show temperature values in c programming
I have question regarding selecting channel from multiplexer. I'm trying to receive some temperature reading from the two sensors which shared the same address and while I'm using one sensor, it can ...
3
votes
1answer
162 views
How do “beyond the rails” analog switches work?
I'm familiar with using CMOS switches ("transmission gates") for switching analog signals, but you can't use them for switching voltages beyond their supply rails. (So if you have a single supply ...
3
votes
2answers
99 views
How can I multiplex my oscilloscope probes?
Let's say that I'm tasked with the job of measuring the propagation delay of each inverter in a 7404 hex inverter. I've got a pulse generator, a power supply, and an oscilloscope with two probes, so ...
2
votes
4answers
156 views
250 LED control
I am in the process of designing an automated rock climbing wall that will have 250 monocolor LEDs lit in a predetermined pattern that will be changing every 10 seconds. My controller (actually a PLC) ...
0
votes
1answer
48 views
Multiplexing and electric capacitance
I'm working on a project, it's basically a hand-drawn paper keyboard based on capacitance.
I was thinking I can multiplex the different lines with shift register (74HC595) and switch (4066), and as ...
0
votes
1answer
95 views
How does a HCF4051BE multiplexer work, at a very simple level?
I'm a totally noob, so please, take this in consideration when replying :)
I want to understand how this multiplexer works. I tried to Google it, but all the answers was too advanced for me.
I mean, ...
3
votes
1answer
214 views
Capacitive touch sensor grid to the Arduino?
I am trying to build 8x8 grid that consists of capacitive sensors which we have successfully made by using a high resistors and copper sheets. I used Arduino's library to control it, but my problem is ...
1
vote
1answer
102 views
Switching 100 different LM35 with one uC [closed]
I want to read the temperature of about 100 different LM35 with only one ATmega16 or ATmega32.
I want to read 8 LM35 at one time and switch to the next 8 and so on.
what kind of multiplexer or switch ...
0
votes
1answer
108 views
MCP23017 in series
I have a hand full of MCP23017 (16 bit multiplexers/ I/O Expander) but I can only get 8 IC on the bus due to the limit of address but I need 200 pins (about 13 ICs) for a 8*8*8 RGB cube
and was ...
5
votes
2answers
115 views
Slow PNP turn-off time, how to optimize it
I'm multiplexing a pair of Nixie tubes. The high-side control is done with two pairs of transistors, MPSA92 high-voltage PNP to switch the 160V to the tubes, and a BS108 to control the base of the ...
0
votes
2answers
106 views
Is it possible to monitor analog multiplexer inputs without changing the selector signal?
If you have 8 analog input sensors (or 2 or 9 or 738479) is there a chip / is it possible with microprocessor programming to actively monitor all of the channels? Say you had 8 rotary potentiometers ...
0
votes
0answers
36 views
Is my interpretation of this problem regarding a 7-word mux correct?
I have a problem on an assignment which states to draw a block diagram for a 7-word MUX and determine how many control switches it should have. I'm not exactly sure what the problem means by "7-Word." ...
1
vote
0answers
134 views
Counters VHDL multiplexer 7 segment
I am new to vhdl and my code may seem stupid but i am still struggling i am trying to make a bcd counter using spartan 3 kit i have a problem multiplexing the 7 segment and i know i should use ...
0
votes
4answers
123 views
In CMOS, can I assume the delay of a multiplexer is negligible compared to the delay of an inverter?
Let say I have a ring oscillator, and I modify the ring so that the output of an inverter is connected to an input of a 2-to-1 MUX, and the output of the MUX is connected to the input of the next ...
1
vote
0answers
111 views
MCP4131 resistor on SDI/SDO multiplexed pin?
I'm using the MCP4131 digital potentiometer to control the brightness of a LED using an Arduino Uno. The MCP4131's interface is SPI and it has a multiplexed SDI/SDO pin (pin #3).
The datasheet ...
1
vote
3answers
67 views
Multiplexing RF Sources to a Single Output
I have two wide-band VCOs, one 800-1600 MHz and the other 1600-2700 MHz which I would like to multiplex so that they can share the same output (SMA jack). (They are both configured to produce ~5 dBm ...
0
votes
0answers
52 views
Making a 2-bit 8x1 source selector from 2 1-bit 8x1 Multiplexer
I am working on a prelab for my Digital Logic Design course and this is the question I have been given. I have to use WinLogiLab DigitalSim utility at first to create this, but due to limitations must ...
2
votes
2answers
145 views
ATtiny/ATmega programmer board - need a 6 x 1:3 Mux solution
Hey so I'm trying to create a circuit on perf board that allows me to program three different types of chips using an Arduino Duemilanove as ISP. Those chips are the ATtiny85, ATtiny84, and ...
1
vote
1answer
273 views
Is there an easy way to multiplex the state of multiple switches in an AC circuit?
If I had a circuit like this...
*Blurple boxes represent unknown devices/circuitry
What would be the simplest way to transmit the states of the switches, using only a single wire?
In essence I'm ...
1
vote
1answer
756 views
Control 4 digit 7-segment (2 digits number each) using Verilog
How to program using verilog, where i want to control 4 digit 7-segment display, that will show 2 digits number for first and second 7-segment display, and the others with 2 digits number too. I know ...
2
votes
1answer
50 views
Multiplexing a phase shift keyed signal
There are a number of great tutorials online explaining phase shift keying as a means of digital wireless communication, but none of them seem to cover the topic of multiplexing. At first glance, it ...
-4
votes
1answer
95 views
implementing palindrome using 2:1 multiplexer
A 4 bit number , ABCD is a palindrome when A is equal to D and B is equal to C . Draw a circuit to check whether a given 4 bit number is a palindrome or not. Use only 2:1 multiplexers.Do not use any ...
1
vote
1answer
58 views
What is maximum frequency of ADG506 Multiplexer?
I want to use AD506 as a multiplexer in a high frequency design (50MHz).
It receives 1.2 Vpp sine wave signal from AD9850 and sends the signal for amplification.
According to page 2 of its ...
3
votes
1answer
148 views
Multiplexers used as a switch seem to “leak” when power is cut
Description
Attempting to build a device using the Arduino that will allow me to remotely restart a cluster of desktop computers that I have. The device works by momentarily connecting the RESET ...
0
votes
1answer
96 views
Drawing circuit to compute mux
Ok so I've been working on this problem for a while now. I've been given
mux(\$p_{11}, p_{10}, p_{01}, p_{00}, x_1, x_0) = p_{x_1x_0}.\$
I found the boolean formula to be:
\$(!(x_1x_0))p_{11} + ...
-1
votes
1answer
2k views
How can I construct an 8 x 1 multiplexer from an 4 x 1 multiplexer and 2 x 1 multiplexer? [closed]
How to design an 8x1 MUX from 4x1 MUX and 2x1 MUX ?
1
vote
2answers
185 views
Can I simplify this to a 2-to-1 multiplexer?
I have the following 4-to-1 multiplexer circuit:
simulate this circuit – Schematic created using CircuitLab
With this truth table:
...
2
votes
2answers
133 views
Proper use of analog mux HEF4051B
I'm having problems using HEF4051 as an analog mux. I'm using it to switch between different audio toslink signals. Right now I'm only testing it with one signal and it works for 1-2 seconds when I ...
3
votes
3answers
257 views
Advice… Shift registers, multiplexing, or both
I'm doing a project that has a lot of displays, in the form of single leds or 7-segment displays. So the question is in the title. Using 8 bit registers, if I used them for all the leds, it would take ...
2
votes
2answers
377 views
Multiplexing a big 7-seg display with MAX7219
I've a problem with this circuit, it should drive 2 (or more) big 7-segment display using a MAX7219 and the relative Arduino's library. It uses ULN2003 and UDN2981 to use +12V and a series of 5 led ...
3
votes
2answers
352 views
Driving 7 segment displays through Raspberry Pi's GPIO
So I was thinking of wiring up four 7-Segment displays through the Raspberry PI.
I'd do that by multiplexing each of them, and came across this:
...
0
votes
2answers
88 views
Select Bits in 4-to -1 MUX
Can there be 3 select bits in a 4to1 MUX?
I needed it for a particular application and have no alternative.
3
votes
2answers
183 views
In search of a component or device that switches multiple lines based on input selection
Okay so the foundation for my curiosity is that in dealing with Arduinos, I found they can be used to program the similar but smaller ATtiny chips. This is the main hookup configuration that some of ...
5
votes
1answer
453 views
Controlling MOSFET with microcontroller
I'm trying to use a P channel MOSFET (FQP27P06) to  multiplex 4 large common anode seven segment displays. I'm using a TPIC6B595 high voltage high current shift register to sink the segments for each ...
0
votes
2answers
3k views
Design a full subtractor using 4 to 1 MUX and an inverter
I can't wrap my head around it. Any tips?
I need to draw a circuit diagram of a Full Subtractor using 4-to-1 Multiplexers and an Inverter.
FS diagram:
MUX diagram:
Do I need to combine them ...
0
votes
1answer
81 views
Shift register clocking and latching delay from microcontroller
When latching or clocking a shift register from a microcontroller, should there be a delay in between setting the clock or latch pin to high and then resetting it to low? How long is this delay ...
1
vote
1answer
66 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 ...
0
votes
1answer
137 views
Current and power-on time in LED multiplexing
Supposing to multiplex a LED matrix, after a certain number of columns the LEDs power-on time becomes too low in order to ensure a good LEDs brightness so you need to increase the current in order to ...
1
vote
1answer
90 views
Need help understanding charlieplex circuit
I understand the principle behind charlieplexing, however I don't understand how the circuit below works. Say I wanted to illuminate LED5, wouldn't I set Pin1 to OUTPUT-LOW, Pin2 to INPUT, and Pin3 to ...
1
vote
2answers
317 views
Single and Double Click on Arduino Multiplexed Buttons
On my arduino project i have 8 buttons connected to a 4051 Multiplexer.
I would however like to add single and double click funcionalities to each of these buttons, but i can't find a way to do it.
...
2
votes
1answer
259 views
Why I am getting Unexpected EOF? What's wrong?
I am learning VHDL and I am trying to do a simple Generic MUX. It is my code:
GenericMUX.vhd
...
0
votes
2answers
143 views
How to multiplex a two-way data line?
I have a use-case where I need to control 4+ sonar sensors with a pic 628A microcontroller. The pic is also responsible for controlling a GPS and LCD so pins are scarce. The sonar sensors each have a ...
2
votes
1answer
303 views
Multiplex 125kHz RFID antenna
I'm looking to follow up on a question (asked by another) that wasn't answered to my satisfaction in another question.
RFID Antenna Array
I am successfully using the ID Innovations ID-2 chip to read ...
0
votes
1answer
154 views
8:1 Multiplexer With 5 Parameters of F(A,B,C,D,E) = ABCD +B'CDE+BC'D'
I am trying to create a multiplexer 8:1 with 5 parameters of the function $$F(A,B,C,D,E) = ABCD +B'CDE+BC'D'$$
what I did its to right it as minterms so what I get is:
$$ F = ABCDE + ABCDE' + AB'CDE + ...
0
votes
2answers
114 views
LEDs in the audio path - linearity? [closed]
I'm repairing an ancient stereo multiplex decoder which has diodes in the signal path for mono/stereo switching.
For headroom reasons, I need plenty of Vf on these diodes, which are pulled up by a DC ...
0
votes
5answers
149 views
Programmable IO
I have three bit input and would like to have a three bit output programmed for the input combinations.
...
