Questions tagged [charlieplexing]
Charlieplexing is a multiplexing technique allowing to control N \$\times\$ (N-1) LEDs or buttons with N I/Os.
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2answers
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Is Multiplexing ever superior to Charlieplexing?
I've reviewed the two methods, and multiplexing really only appears to have one advantage, that it would be easier to track down a failed LED than in a Charlieplex array.
Can someone more ...
10
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7answers
34k views
How do I control several hundred individual leds with Arduino(s)?
I am working on an electronics project which involves hundreds of LEDs. (Talking upwards of six to seven hundred LEDs...a lot, I know.) Is there any way to control this many LEDs with one or a couple ...
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4answers
1k views
Control 16 motors with 8 relays
I build a project using 8 relays in a matrix (charlieplexing) to control 16 motors (actuators), plus one relay to control two DPDT relays to reverse the power for the motor to turn reverse. I only ...
6
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2answers
3k views
7-segment LED display with multiple digits
I was looking at the datasheet for the LTC-4627JR, and it looks like each digit shares a common anode, and each segment shares a common cathode.
My question is given this configuration, I don't ...
4
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1answer
539 views
Charlieplexing different LEDs
I have four LEDS (Red,Green,Blue,Yellow) and want to use charlieplexing to light them up.
I'll use an Attiny13V which needs 1.8 to 5.5V. I think one CR2032 with 3V will be suffice for the µC.
The ...
3
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2answers
3k 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 ...
2
votes
3answers
1k views
CharliePlexing on a breadboard
I was making a breadboard demo for a Microcontroller class. Basically my project is to make a score keeping device. I want to drive 4 seven segment displays using an atmega8. I read about charlie ...
2
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4answers
475 views
Charlieplexing Topology Question
I'm sitting here with a pencil and paper trying to arrange a charlieplexed 5x8 LED matrix. I'm trying to arrange this in such a manner that no two lines cross each other. Without a guiding theorem of ...
2
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1answer
466 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 ...
2
votes
1answer
2k views
Chaining limit for shift registers in large led matrix
I am thinking of trying to build a large led matrix in a way that is both modular and scalable (maybe up to around 100x100, or 500x16).
My thought is to make a single 8x8 module that I can make a few ...
2
votes
1answer
501 views
How to debug a circuit that uses Charlieplexing and PWM with LEDs under ISIS?
Using mikroC and Proteus ISIS, I have built a circuit that uses a PIC12F629 (link to datasheet PDF). It controls several LEDs using Charlieplexing technique (and additionally PWM them to change their ...
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2answers
698 views
Charlieplexing 7-segment display segments vs segment
I understand the principle of charlieplex and the use of tri-state. What I don't understand is, can I light all segments on a display at once or do I have to light one segment at a time?
Say I have 8 ...
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vote
1answer
2k views
How to increase current drive of Charlieplexed LED array?
I am driving 15 LED's with a Charlieplexed circuit (using an Atmel ATTiny13). I've reached the current limit per I/O pin of 40mA and would like to drive the LED's higher (they're rated at 50mA).
Is ...
1
vote
1answer
206 views
How to connect a large number of multi-throw switches efficiently?
I have a number of 7 pole single throw switches that I need to connect together in some sort of grid configuration to a microcontroller, while minimizing the number of pins on the micro and the number ...
0
votes
5answers
842 views
How can I use Charlieplexing with common anode RGB LEDs?
I've an ESP32-based dev board (LoLin32) which has 26 digital I/O pins. I want to connect 25 common anode RGB LEDs to it. Connecting them in the 'normal' way would require 75 I/O pins, which I don't ...
0
votes
1answer
2k views
Building a 3x3x3 LED cube?
I need to built a 3x3x3 LED cube. I need to be able to turn every LED on (not at the same time) in different patterns. I need to use Charlieplexing (note that any other method is not a viable option),...
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2answers
55 views
Trouble understanding Charlieplexing problem
I am trying to make a circuit that uses 3 pins to drive 6 LEDs using charlieplexing. The cicuit im using is this:
What I don't understand though, is that when I want to turn D1 on, PB0=1, PB1=0, and ...
0
votes
1answer
182 views
For 12X8 LED array with any 1 LED glowing at a time, should we charlieplex or use 74HC595n?
Apologies in advance for probably missing a lot of things. I'm pretty new to electronics.
I'm building a 96(12X8) led (monochrome ultra bright, white) multiplexed array, driven by an Arduino nano. ...
0
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2answers
957 views
Arduino - Controlling 8 RGB LEDs (beginner question)
First time poster here.
I have an Arduino Uno project that will require 8 RGB LEDs to be controlled. They will be turned on and off with pushbuttons, cycling through red, then green, then blue, then ...
0
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0answers
553 views
Reading an LDR array with a Raspberry Pi
I am trying to repurpose a replica GPO 746 using a Raspberry Pi, however the rotary mechanism is rather different to that in an original 746. The circuit has 12 LDRs arranged in an array (3 columns, 4 ...
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2answers
1k views
200 LED through arduino via SN74HC595N shift register
I'm very new to any forms of multiplexing let alone electronics itself. From what I have researched, I can add more inputs/outputs to an Arduino via a shift register. I bought 10 SN74HC595N shift ...
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2answers
229 views
Charlieplexing ledstrips together
I know there is a lot of charlieplexing tutorials out there but non of them are very suitable for my case. I want to charlieplex 4 ledstrips together and control them by an arduino. This means that i ...
