Questions tagged [charlieplexing]
Charlieplexing is a multiplexing technique allowing to control N \$\times\$ (N-1) LEDs or buttons with N I/Os.
21
questions
17
votes
2answers
7k views
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
votes
7answers
33k 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 ...
6
votes
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
votes
1answer
534 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
votes
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
votes
4answers
473 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
votes
1answer
444 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
496 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 ...
1
vote
2answers
648 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 ...
1
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
203 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
4answers
682 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),...
0
votes
2answers
52 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
169 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
votes
2answers
920 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
votes
0answers
525 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 ...
0
votes
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 ...
-1
votes
2answers
220 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 ...
