A shift register is a cascade of flip flops, sharing the same clock, in which the output of each flip-flop is connected to the "data" input of the next flip-flop in the chain, resulting in a circuit that shifts by one position the "bit array" stored in it

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22 views

Shift register 5V VCC and data while 3v3 serial?

I want to use 5V for VCC and data pins for shift registers (HC595 and HC165) with a common GND while using 3V3 clock, I haven't tested yet. But is it okay to do that ? or it will reduce IC life span ? ...
3
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3answers
427 views

Can I debounce after a shift register?

I am rewiring a cheap old organ for digital and want to use shift registers to read all the keys. Is it possible to debounce the keys after the shift registers, or do I need to do it before? Either ...
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1answer
85 views

74HC595 Shift register - output pin polarity

Most shift register tutorials I've seen have the output pins connected to ground (for instance: http://www.arduino.cc/en/Tutorial/ShiftOut), however I've seen at least one circuit that connects them ...
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2answers
82 views

Can a computer use shift registers as memory?

An 8 bit shift register stores a byte of information. Would it be possible (in principle) to create a computer that uses shift registers for memory instead of HDD technology?
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2answers
200 views

Shift register explanation (parallel in - serial out)

The task is to implement a 4-bit shift register with parallel input and serial output using JK flip-flops and standard logic gates. The solution is below: This is what happens on the output: I ...
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1answer
92 views

Looking for a way to output 100-144 Analog Channels from Arduino

I've been searching for days and found 2 ways that could work, but not sure about implementation: Using shift registers like in: ...
2
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1answer
96 views

How can two separate devices send clock data to a shift register IC?

I'm using a microcontroller to clock a byte into a 74HC595 shift register and latch it. It then sends a signal to the other device which send 8 clock pulses when it is ready to receive the byte. So ...
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1answer
98 views

Generating pseudo-random numbers with restricted hardware

I have a need to generate a 448-bit value that appears random, for use in a test circuit. The "randomness" of the values is not overly important; the size of the generator hardware is. I am using an ...
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2answers
77 views

PN sequence generator using linear feedback shift register in VHDL

I got a code for PN sequence generator using linear feedback shift register in VHDL. I am using 1010 as a initial seed but in the output all the four PN sequences ...
2
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2answers
107 views

Shift Register Programming with 8 and 16 bit drivers

I built up a test circuit using 2 74hc595n shift registers to control a total of 16 leds with success. In the interest of saving space, I designed my circuit board to use one STP16CP05MTR shift ...
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2answers
68 views

Best way to use multiple decoders for an LED matrix

I'm designing a 16 x 32 RGB LED Matrix and its controller / driver board. So I've designed a couple of solution approaches and I'm wondering if there is a better way to drive multiple 4 to 16 line ...
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2answers
114 views

74hc595n shift register error

I want to put in series 2 74hc595N . I made the schematic from here: When I send a value the first register sends it also to the second one. I have same value on both. I change them (master/slave) ...
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0answers
62 views

How to increase number of LED blocks in a moving LED display

I have been working on a project where I have to make an 80x20 sized moving LED display. I'm using a decade counter to shift the characters being displayed. I want to know, in the programming ...
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2answers
132 views

Design a 4-bit PISO shift register with 4 DFFs and 3 AND gates

I want to design a 4-bit PISO shift register with 4 DFFs and 3 AND gates. I have gone so far that these two designs can be implemented, but I can't go further minimizing it so as to use 3 AND gates ...
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1answer
94 views

Emf interference on arduino and breadboard , using 74HC595 shift register, how to prevent it?

I’m using a 74HC595 chip (shift register) NPX semiconductors, connected to and arduino board. Basically the shift register switches on and off 8 leds in sequence. Everything seem to be working, code ...
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2answers
89 views

Building circuit for n-relays using flip flops, is this the best solution?

I'm trying to build a circuit for n relays, each relay should hold it's state (ie latched). My first Idea was to use decoders, but clearly this was a bad option, since the state of the relays won't ...
2
votes
2answers
298 views

Why is shift register very important?

I learned about shift registers a few weeks ago but I don't know why it is very important and everyone said that it is necessary for microcontroller, etc. Please make sense for me.
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1answer
94 views

Increase toggling speed of PNP for PWM

I got a shift register which I use to PWM LEDs. Since I multiplex this toggling I noticed some "afterglowing" if the next LED is not active of the same color. (RGB cathode) Multiplexing by the MOSFET ...
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1answer
243 views

What are Vcc and GND on a shift register?

What are Vcc and GND on a shift register? I thought that I had to provide a positive voltage to the IC via the Vcc, but turns out that I can operate my shift register without powering the Vcc. ...
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1answer
45 views

Help designing a serial adder [closed]

I need to build a circuit that adds two n-bit 2's complement numbers. the two numbers have to be stored in shift registers. The circuit should start with the least significant bits of each number and ...
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1answer
69 views

FSM for predesignated process (How to draw the state diagram)

let me start by saying this involves some homework problems so if you could help guide me a bit I would greatly appreciate it. I have been working with finite state machines for a bit in my course ...
0
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0answers
59 views

Parallel-in, parallel-out, universal shift register

I am trying build circuit of parallel-in/parallel-out universal shift register. I have found circuit in the Internet. Here it is I have tried to do this using MicroCap , but it doesn't work as ...
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4answers
155 views

Shift Register Counter

I am working on a project with my MBED microcontroller and I'm running into some snags, because I'm new to it and getting myself confused with how exactly everything works. I have my MBED hooked up ...
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1answer
38 views

Parallel-In-Serial-Out with Parity?

Can someone recommend a shift register IC with integrated parity or CRC generator? Is there such a thing anyway?
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1answer
33 views

HCF4021BE usage w/ uC

http://www.datasheetarchive.com/dlmain/Datasheets-30/DSA-599035.pdf The above datasheet is useless to me. (I do know my way around a datasheet somewhat, though) 1) Can someone explain how the heck ...
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1answer
98 views

Pull up does not work

I got a breadboard with some logic on it. Including it's own power suppply. It is connected to my Arduino Mega 2560 to fill a shiftregister with some bits. Whenevery my arduino is in a undefind state ...
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1answer
33 views

There is no 'latch pin' on MC74HC164A shift register

Unlike a 74HC595, this shift register (http://www.onsemi.com/pub_link/Collateral/MC74HC164A-D.PDF) doesn't have a latch pin. How then do I output the data stored in the registers (to something like an ...
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1answer
103 views

Toggle transistors with an shiftregister to light up an LED

First of all I'm quit new to electrical engineering. I had it 3 years in class but I didn't do well. So here is what I plan. I got some shift-registers (74HC595) Which I'll set with an arduino mega ...
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1answer
101 views

Unable to keep 2nd shift register in chain of 3 from “leaking”

I am working on a word clock, and I am using 3 shift regsiters (CD4094BE) and 3 darlington transistor arrays (ULN2003A) to control whether or not 21 different words are on or off. The words consist of ...
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1answer
91 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 ...
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1answer
53 views

Issue driving a shift register

I am trying to drive a 74ACT299 shift register with a Microcontroller. Looking at the datasheet I thought it was pretty simple. Set the data bit then pulse the clock, repeat. After I wrote the code, I ...
0
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2answers
158 views

binary number is parallel-loaded into a shift register

A binary number is parallel-loaded into a shift register. The shift register is then commanded to shift right" for one clock pulse. How does the value of the shifted binary number compare to the ...
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3answers
102 views

how can i get parallel data entered into a shift register circuit

If i want to use a shift register circuit to input several binary bits at once (parallel data transfer), and then output the bits one at a time over a single line (serial data transfer). describe how ...
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3answers
405 views

Will 74HC595 as LED sink damage LED when pin goes high?

If used as a LED sink, what happens if a 74HC595 pin goes high? Might the LED blow? I expect that when a pin is low, current will sink and the LED will light. What about the opposite condition? ...
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1answer
198 views

Simple high side driver for multiplexed 7-segment displays?

How can I best drive and switch high side power (for multiplexing) between the 7 displays with as few components as possible, for under $2. I am trying to simplify a design. I have a custom board ...
3
votes
2answers
732 views

Sharing Clock and Data for 74HC595 and CD4021B Shift Registers?

Can output shift registers (74HC595) and input shift registers (CD4021B) share the same clock and data lines on Arduino using SPI, with different latch pins "activating" either chain for input or ...
0
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2answers
115 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
votes
1answer
155 views

problem with LED Matrix circuit

I want to create a LED Matrix circuit with 74HC595 shift register and 2n7000 mosfet. The schematic is as follows. I have mentioned voltage levels at various points. All the control signals of ...
0
votes
1answer
67 views

Generating a desired pulse train in Xilinx ISE software

Need some help with VHDL and FPGA since I am new to it. I have a Virtex-4 FPGA and I wish to generate a binary pulse train of 16 pulses from FPGA using VHDL programming. My desired pulse train will ...
3
votes
2answers
327 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 ...
3
votes
3answers
165 views

Can several CS pins be multiplexed with a shift register?

When sharing a SPI data line between several ICs and an Arduino, what exactly are the frequency constrains of the CS pin? Can I use a shift register to multiplex the CS pins (thus only requiring one ...
1
vote
1answer
187 views

communicating to shift register with ATmega32 without using given SPI pins

I'm trying to use an ATmega32 to communicate to a MAX7219 chip for multiplexing with an led matrix. However, I do have multiple different devices that I want to communicate with. I am trying to ...
1
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2answers
114 views

Displaying character OSL641501-ARA dot matrix LED

I am learning to control this dot matrix LED (OSL641501-ARA datasheet). I have seen some tutorials on how to control it with 2 shift registers. The problem is I am totally confused with the concept of ...
1
vote
3answers
175 views

Lower power version of ULN2803?

I want to drive around 80 LEDs from an Arduino with 10 8-bit shift registers. (Some will be RGB LEDs; I count those as 3.) I know of the TPIC6B595 high power shift register but it's expensive: 1.75 ...
1
vote
1answer
443 views

CD4094BE Arduino problems

I'm trying to build a circuit which uses three 4094's to give me enough outputs to drive a number of LED's. I've built a few similar circuits before in the past using the same code and schematic, but ...
1
vote
1answer
1k views

PWM driven LED array over a shift register

I am trying to drive 8 LEDs connected to a 74HC595 shift register with PWM. I want to be able to set each LED to a different brightness. The PWM signal is connected ...
0
votes
1answer
611 views

What are the functions of the ULN2003A and HCF4094 within this circuit?

We are building a wordclock and want to know what the following components do within the circuit: ULN2003A driver IC HCF4094 shift register This is the schematic:
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2answers
728 views

LED driver on 74HC164 - need explanation

I'm building thermometer with long led bargraph (is that correct word?). It will be 60x 0805 LEDs. I want to use low-cost PIC16F1503 microcontroller with just 12 I/O pins. I have few spare 74HC164 ...
0
votes
2answers
93 views

Driving an electromagnet through a shift register? [closed]

I want to know if it is reasonable to use a shift register to control electromagnets. We want to drive electromagnets with about 400-500mA. The TPIC6B595 data sheet claims "Each output provides a ...
1
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1answer
303 views

Help me understand this shift register timing diagram

My basic understanding of using a shift register to convert serial to parallel data is this: On every clock pulse, the state of the serial data pin is read As data is read, it gets shifted in to the ...