A numeric display consisting of seven segments per digit, allowing characters 0 to 9 to be displayed by selecting which segment is on or off. Can have each digit independently controlled, or can be multiplexed to reduce pin count. An 8th segment can be included for a decimal point.
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0answers
33 views
Design a synchronous up/down counter using a JK flip flop [on hold]
I need to design a synchronous up/down counter using a JK flip flop, that must be able to work on a range varying from 0 to 99. It also has to be able to count by 1, by 2 and by 3.
A 7-segment ...
0
votes
2answers
48 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 ...
-2
votes
0answers
24 views
dimensions of a seven segment display [on hold]
I want to purchase a smallest 4 digit seven segment display. I want to know what is the smallest dimension of that 7 segment display and where I can puchase it?
25
votes
5answers
2k views
Why do 7 segment LED displays break apart when I brush my teeth?
This question might sound silly, but it is very serious (although geeky, I must admit).
When I use my electric toothbrush in front of my alarm clock (one of those with a big red LED display), the ...
1
vote
4answers
65 views
Outputting a clock signal from an FPGA
Referring to question here: Click here, I'd like to use the 16 channel LED driver to run my 7-segment displays. I'm using a Spartan 6 LX9 FPGA to implement a 16-bit microprocessor that will take care ...
0
votes
1answer
85 views
Driving 7-Segment Displays using a microcontroller
Before I start out, let me just point out that I'm new to hardware design. In fact, this is just hobby for now, but might turn into something later. Because of this, I don't follow any standards per ...
0
votes
1answer
61 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 ...
0
votes
2answers
87 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 ...
2
votes
5answers
2k views
How do I exchange LCD display with 7-segment LED's?
I have bought a cheap radio controlled clock, and I want to make a hack that replaces the existing LCD display with 7-segment LED's.
With my voltmeter in AC mode, I can measure voltages(with respect ...
2
votes
4answers
2k views
How to connect multidigit 7seg common anode/cathode display to cascading shift register?
How can I connect this type of 7 segment display to cascading register like 74HC595? I know I can use 7219, but at the moment I have those cheap registers and would like to see if it's possible.
Not ...
0
votes
2answers
100 views
Possible to use 7447 to drive common-cathode 7 segment display?
I know that the 74(LS)47 is designed to drive common-anode displays. However, is it possible to make it drive a common-cathode display? What is the simplest (in terms of components) way of doing this?
...
1
vote
2answers
101 views
How to drive a single 7 segment display with I2C?
I am looking for a solution to drive a single 7 segment display with I2C. I found some websites that shows 2 or 4 digits with I2C but I didn't find a solution for driving a single digit. I'm making a ...
0
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2answers
63 views
Difference between 7446,47 etc
I have looked in the data sheets, as well as the TI article, but I am still unsure of the answer to this question:
What is the practical difference between a 7446 ("BCD to 7 segment decoder/driver ...
0
votes
1answer
67 views
7 Segment display binary to decimal
I have a few questions about 7-segment LED displays.
When we build a circuit using 7 segment (common-anode) and decoder (7447), we also use 4 tactile switches to make combinations. Should I directly ...
1
vote
2answers
96 views
7-segment display driver IC [closed]
Which IC can I use to control 7-segment display? I want to make simple projects like a reaction timer but I don't have an Arduino or some other microcontroller available. What ICs can I use instead?
1
vote
4answers
2k views
Binary to BCD converison
I have an 8-bit number that the values ranges from 0 to 99. I need to convert that to a proper 8-bit BCD representation of the number using digital circuits.
In case you need to know, the original ...
3
votes
1answer
74 views
How to read SAA1064 7-segment values
I have a central heating system that displays it's info and error codes on 4 7-segment displays. These displays are driven by a SAA1064, like so:
This SAA1064 (datasheet here) receives it's ...
1
vote
1answer
88 views
Display for outside (sun)
I am currently working on a little project where I would like to have a display which would have to support this format:
00 00:00:00
This would have to be used outside on a motorcycle ...
0
votes
2answers
80 views
Driving three large 7.5v common anode 7-segment displays with Arduino
I'd like to drive three common anode 7.5v 10ma 7-segment displays using my arduino uno and a few 74HC595N shift registers. The problem is the uno only outputs 5v 40ma on the digital pins.
I am ...
2
votes
2answers
143 views
BCD to 7 Segment Decoder Schematic: Need help fitting in page
I am working on the schematic for a BCD to 7 segment decoder right now. I understand the logic, but it is the design of the schematic that I need help with.
Here is my schematic so far:
As you can ...
2
votes
2answers
76 views
low power displays
What kind of displays can I use effectively with a coin cell battery (CR2450)? The backlight or the entire display would be on only when necessary. From previous answers I know that a liquid crystal ...
0
votes
1answer
94 views
7-segment driving circuit not working as expected
I have designed and built the following 7-segment driving circuit utilising an Arduino Micro in order to try and further understand electronic circuit design:
simulate this circuit – ...
1
vote
2answers
2k views
How to drive a 12V common cathode 7-segment display with 5V signals and BJT transistors?
I'm having trouble designing a driver for a large (5") 12V common cathode 7 segments display using a 74HC595 shift register and BJT transistors. Below are the schematics for the component (display) I ...
2
votes
2answers
2k views
Arduino + Max7221 + Common anode 4-digit 7-seg LED array?
I'm trying to hookup a common anode 4-digit 7-segment LED array to my Arduino via a Max7221 IC.
Here's a hard-to-see (sorry!) pinout for my LED array (my LED array is the bottom common anode one, ...
1
vote
1answer
278 views
Display digits on 7 segment 3 digit LED display with Launchpad
I have a 7 segment led display with 3 digits (BT-M512RD-DR1
) and Valueline Launchpad MSP-EXP430G2
I connected LED display according to this answer and here is my version of the sketch
But I am ...
0
votes
0answers
88 views
Help with ICs, 2-digit 7-segment displays, 74HC4515
Can someone show me how to connect two DC56-11YWA 2-digit 7-segment LED displays to an Arduino Uno or Mega2560 using two 74HC4515s? Is there another IC that I will need in addition? I want to display ...
2
votes
1answer
262 views
Constructing Excess 3 BCD to 7 segment decoder - circuit hints needed
I am currently trying to construct a circut for an Excess 3 BCD to 7 Segment decoder. Therefore the input range ranges from 0011 to 1100 in binary inclusive with the rest of the inputs being don't ...
0
votes
1answer
128 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?
...
3
votes
2answers
156 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 ...
2
votes
2answers
298 views
How to filter out the mains power supply spikes?
I'm purposely dropping AC from its normal levels (230VAC @50Hz) just to analyse the behaviour of a DC motor drive board that I have.
When the AC mains voltage falls below 180V, the 7 segment display ...
1
vote
2answers
129 views
Reducing power consumption in controlling 40 7-segments [closed]
Following that post here: Designing a large 7-Segment display
To give you the basic approach I did that:
form the uC to shift register followed by ULN2003, then connected 8 7-segments together
Put ...
1
vote
3answers
111 views
Seven Segment problems,voltage and current
I want to ask a question about a project I am making, I am using a seven segment.
Here is Information about the seven segment: http://www.4project.co.il/documents/doc_188_54.pdf
I want to use this ...
0
votes
2answers
89 views
How to cycle through bits of information for a hex display?
I am doing some work with a Hex Seven Segment Digital Display with a built in decoder that takes in 4 bits of information. Controlling it I have 4 cascading T-FlipFlops whose outputs are inverted so I ...
2
votes
2answers
413 views
Weird ULN2003 to 7-segment behaviour in Proteus
I'm trying to drive a 7-segment common anode, in the following connection, however there is no output the comes from the ULN2003 at all, its like when it gets a 0 in the input, it gives a tri state ...
1
vote
3answers
481 views
Driving 12 Seven Segment Displays from an Arduino
I will be using the 14 input/output Arduino. My goal is to create a plane radio console for use with a flight simulator. I am very competent at writing code, but have little knowledge of electrical ...
1
vote
1answer
241 views
Designing a large 7-Segment display
I'm trying to design a product that have the following features for mass production, and I'm asking from your experience, how to get the lowest price for the components, quality of the chips in terms ...
0
votes
2answers
172 views
What seven segment display do I have? [closed]
I'm having a surprisingly hard time figuring out which seven segment display I have on a board I'm looking at.
It is common anode, as there is one pin tied directly to Vcc.
It's like this, except ...
3
votes
1answer
254 views
Why is my LCD stop to work correctly when my pump is running? [duplicate]
I have a 8x8x8 lcd/led/button module (tm1638 chip) connected to my Arduino r3. When I attach a pump (GPH350, 1.5A, 12V to the same power supply (12V, 5A) - my display stops working correctly (only ...
6
votes
1answer
5k views
Using 4 digit 7 segment LED
I have a 7 segment display that has 4 digits. What will I need to make use of this? Can a single microcontroller handle the operation? I mean PIC16F690...I saw also a MAXIM chip that drives these kind ...
1
vote
0answers
252 views
MAX7219 interfaced with ATmega128 producing strange results on 7 segment display
I have built a circuit using an ATmega128 interfacing a MAX7219 decoder to control a 7-segment display. I would appreciate if anyone could help me figure out a problem I'm having with my setup. I am ...
2
votes
3answers
665 views
Cheap 4 digit 7 segment display driver
Can anyone recommend a cheap ( less than $4 ) driver chip capable of driving a 4 digit, 7 segment display with the center colon? I'm very familiar with the likes of the MAX7219 and similar but they ...
5
votes
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?
-5
votes
1answer
139 views
How to change colour of a 7-segment display using the Arduino [closed]
Is it possible to change colour of a 7-segment display using an Arduino Uno?
1
vote
0answers
228 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 ...
3
votes
2answers
182 views
Shift Registers Controlling Seven-Segment Display without a Latch?
I'm restoring a Model H Skee-Ball machine, and these old models have a bunch of hardcoded settings and unreliable switch detection, so I want to replace the main control circuitry with something ...
1
vote
4answers
5k views
Is it possible to drive 4 seven segment display with MSP430G2231?
I'm trying to teach myself electronics and my goal is to create a digital clock with 4 digits.
I have an MSP430G2231 which has only 8 available ports as far as I can tell.
I saw some methods for ...
0
votes
2answers
266 views
Multiplex two I2C ICs into four 7 Segment displays
I currently have two PCF8574AN I2C 8-bit IO expander ICs. Is there a way I could have two seven segments be driven off one IC (So i could run four seven segments displays off the two ICs that I have). ...
9
votes
3answers
405 views
Low power, seven segment display
I want to display a 4 digit number on a small device that fits in a hand.
I have a CR2032 3V battery at around 230mA, my microprocessor is a 8051 (in a BLE112) usually uses about 0.9µA and I want the ...
2
votes
1answer
246 views
How to use Darlington arrays to source current in a 7-segment display driver
I'm building a driver for a large common-cathode 7-segment display using a shift register and BJT transistors (more details in this question).
I wanted to make it more compact by replacing the ...
3
votes
2answers
383 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:
...
