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

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2
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1answer
55 views

A circuit that outputs one input voltage by default, or another if it is present

I'm trying to come up with a simple design that will take two analog inputs voltages (~0.2-1.6 V each). One is an "internal" voltage and should always be present. The second "external" input can be ...
0
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1answer
38 views

i2C multiplexer to use multiple sensor of the same type

I would like to hook up multiple sensor of the same type (temperature, pressure and so on). The problem is that each sensor can only have 2 different unique values for the register, so can't put more ...
1
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2answers
80 views

How does one implement the following function with these tools provided?

Suppose I have a function defined as follows, such that it is expressed in POS form, with the product of the following max terms of 4 variables (A,B,C,D): 0,3,4,7,9,10,12,15 and I only have a 4 to 1 ...
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1answer
29 views

Can avrdude address individual usbtiny programmers?

I'm envisioning a panel programming jig. In my mind, it consists of a Raspberry Pi, a powered USB hub, and a collection of usbtiny clones each connected to a pogo jig and a target on a panel. The ...
0
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1answer
97 views

Custom built 16x32 (40) LED Matrix controlled by Arduino

I am planning to build a clock / thermometer / info display. I have ordered 10 pieces of 8x8 LED matrixes from ebay (http://www.ebay.co.uk/itm/331064583297). As this is not a pre-built one I have got ...
0
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0answers
18 views

MAR /MBR / MUX Device

How can I modify this circuit to permit loading of the MBR from either the hex keyboard or from memory. As it is, the circuit can only load the MBR from user input.
0
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1answer
50 views

3 State Shift Register with 2-to-1 multiplexers

For a homework assignment I need to Redesign the right-shift register circuit of Figure 12-10 using four D flip-flops with clock enable, four 2-to-1 MUXes, and a single OR gate. The figure ...
0
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1answer
53 views

Strategy for up to 40 ADC inputs using alert feature

I'm working on a project where I want to monitor 40 phototransistors (IR breaker beams), but without having to constantly poll the ADCs. Ideally I'd want a digital pin pulled when one of the beams is ...
2
votes
2answers
95 views

Is it possible to drive a 4x4 RGB common-cathode LED matrix with a MAX7219?

The MAX7219 (datasheet) is a LED matrix driver that's designed to drive an 8X8 single-colour LED array. tronixstuff has an intro on how to use it with an arduino that has some relevant diagrams. I'm ...
0
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1answer
64 views

Transistor Isn't Forming the Connection

I have wired the following diagram. simulate this circuit – Schematic created using CircuitLab My understanding of transistors is relatively poor, and thus I am assuming it has to do ...
-1
votes
1answer
88 views

How to increase current output of a multiplexer for activating a relay

I want to make a multiplexer for my project which needs 24v dc to operate. I am using an OR Gate IC for generating an output. My 4 gate inputs are connected to 6V battery power and I am getting a 6V ...
0
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2answers
99 views

Shift registers(?) failing after being left on a while

Resolved: SLCLR on SN74HC595 was not tied to VCC, so behavior was inconsistent. I have a custom built board that is running seven 7-segment displays, multiplexed using SPI from an 5v Arduino Pro ...
0
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2answers
42 views

How are the Intersymbol Interference and Symbol Time (duration) related to each other?

In a lecture slide I noticed that OFDM(Orthogonal frequency-division multiplexing) mitigates the problem of Intersymbol Intereference over wireless systems because the symbol time is increased, in ...
0
votes
1answer
71 views

Circuit design for short-circuting outputs when needed

I am working with two sensors with 4 pin as output. My question is simple: I want to make circuit that allows me to short circuit the output of either one of the sensors individually when needed. ...
1
vote
3answers
146 views

Driving 60 signals one at a time, in constant sequence

I have an application where I need to turn on/off one of 60 signals one after another in a constant order, ever repeating. (1, 2, 3, ... 59, 60, 1, 2, ...) Only one signal is on at any given time. The ...
6
votes
6answers
835 views

What's the maximum number of outputs you can control from a microcontroller with n outputs?

Been pondering this for a while, and I think it's \$2^{(n-1)}\$ outputs. If I have 5 outputs, I'll use 1 as the signal, and the other 4 as control lines to cascaded decoders, which gets me 16 ...
2
votes
2answers
157 views

Using the raspberry pi to measure multiple electrical circuits

I am looking to use the raspberry pi to measure the power consumption of multiple household electronics and record the information to analyze later on. However, I'm not sure if it's possible to ...
2
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0answers
152 views

What's up with my 74HC4052?

I am using a TI 74HC4052E to multiplex a TTL UART on a Microchip PIC32MX695F512 microcontroller. The expected behavior is for the TX and RX signals to pass through the switches unaffected; sadly ...
0
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0answers
72 views

8 IR sensors and 74HC4051 multiplexer where to place low pass RC filter?

So I've got 8 IR sensors like these Then I connect them to multiplexer. And arduino will run mux's selectors through the loop.. Something about 5-10 times per second(read every sensor 5-10 times ...
0
votes
1answer
83 views

Multiplexer CD74HC4051, always giving a true out

I'm testing a multiplexer from Texas Instruments (CD74HC4051). Both +5V and Ground rails are connected to the Arduino Duemilanove board. I've got a +5V signal in the channel A7 (pin4) and A0 (pin ...
0
votes
2answers
57 views

Multiplexer CD74HC4051, connections and parameters

I'm testing a multiplexer from texas Intsruments, this is the cabling I've done, but varing the selecting pins(9,10,11) nothing happens. The led always stays on. vcc is 5v connected to arduino board. ...
0
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1answer
144 views

Arduino HC-SR04 sensor through CD74HC4051E multiplexer using single wire

I'm trying to get distance using HC-SR04 sensor and arduino. I've connected together Trig and Echo pins on the sensor, then it goes to port A7(pin 4) of multiplexer(selectors configured as follows: S0 ...
0
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0answers
40 views

Multiplex error

I am trying to do basic multiplexing to see if I can get the basics down. When I apply my pins 7,6,5,4 the LED's go on, but if I remove the pins wires the LED's go off. I make sure to apply no power ...
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2answers
70 views

Need an extra pin to control my driver board

I've been searching for a way to add an extra pin to a driver board. The MCU board that i'm using only has 8 pins on the left side and i'm already using all of them. 2 are for powering the driver and ...
1
vote
3answers
75 views

Dimension RGB LED for peak current

I would like to drive a 3x3 RGB LED matrix multiplexed. This means each RGB LED has 1/9 duty cycle and that means it consumes 1/9 of total current. The RGB LED I am using is designed for max 35 mA ...
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2answers
69 views

Mulitplexer to read analog values

simulate this circuit – Schematic created using CircuitLab I have a hall sensor that can measure current up to 25 A with analog output 0~5V. I am using Arduino mega board for programming. ...
0
votes
3answers
53 views

Understanding Digital Multiplexing

As I understand it, digital multiplexers contain multiple inputs (2^N), one output, and N selector lines. The selector lines are used to select which input is mapped to the output line. I then ...
0
votes
2answers
133 views

Multiplexing signals of two wires of a BNC cable and transmitting over a single wire

Background: I have a normal CCTV camera (650 TVL) . It requires a BNC cable in order to feed video signal from camera to DVR. Problem The problem is I have only a single copper wire from CCTV to DVR. ...
0
votes
1answer
201 views

XY table using motorized potentiometers

I'm trying to implement a XY table using 4 units of these motorized potentiometer, controlled by an Arduino. Since I have other uses in mind, I'd like to use as few pins as possible, wich would imply ...
0
votes
1answer
123 views

Multiplexing 4 DC motors with arduino

I'm aiming to control 4 motorized faders with an Arduino. However, I'm still trying to figure out how to best multiplex all the inputs/outputs. Each fader has two potentionmeters and one touch ...
0
votes
3answers
134 views

Can I get away with multiplexing an array mechanical Relays via Mosfets?

I want to use an Ardiuno to drive a Matrix of TO-220 Mosfets triggering mechanical relays instead of LEDS. I am making an array of glow-tubes (read: flickery, purple lightbulbs) as a dramatic screen ...
2
votes
0answers
229 views

Driving multiple stepper motors

During the last days I've been working on driving multiple stepper motors (28BYJ-48 – 5V) with SparkCore and Stepper.h arduino library. I'm trying to drive some stepper motors, but without having to ...
0
votes
1answer
71 views

{Multiplexors} combine 2:1 to from 8:1

I have a question of combining 2:1 to form single 8:1 multiplexor This is acheivable by using 7 2:1, with 4 of it at the first level, 3 of it at the second level, and 1 of it at the third level. ...
1
vote
1answer
63 views

Regarding OFDM (Orthogonal Frequency Division multiplexing)

Could you please briefly explain the IEEE 802.11a OFDM packet structure? In particular, What is meant by "symbol" here? What is the purpose of the packet preamble? What is a "short training symbol" ...
0
votes
1answer
75 views

What is the distortion introduced by a multiplexer?

Question in short: If I have a multiplexer, and my selected input is X volts, I suppose that the multiplexer's output will be X+-ΔX volts. How can I calculate ΔX ? Question with more details: I ...
0
votes
1answer
76 views

How much is the noise of a multiplexer for analog inputs?

I have 4 sensors, each have with two differential output (S- and S+) that I need to use in a differential amplifier (with a gain equals to 1000 in my case). The difference between S- and S+ is ...
2
votes
1answer
70 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. ...
3
votes
2answers
170 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 ...
6
votes
1answer
232 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.
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votes
2answers
157 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
225 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
155 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
241 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
62 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
222 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
696 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
118 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
139 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
200 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
167 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 ...