Electrical Engineering Stack Exchange
Electrical Engineering Stack Exchange

Questions tagged [charlieplexing]

Charlieplexing is a multiplexing technique allowing to control N \$\times\$ (N-1) LEDs or buttons with N I/Os.

Further reading
Charlieplexing explained at pcbheaven

26 questions
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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 knowledgeable explain any other trade-offs?
Chris B. Behrens
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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 Arduinos? I would like to be able to…
kaffolder
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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 need to run one motor at a time. When testing it i…
Kim HJ
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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 understand how to drive each digit separately. For…
helloworld922
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Charlieplexing different LEDs

I have four LEDS (red, green, blue, and 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 forward voltages and current of the LEDs are: …
WeaslB
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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 wondering if it's possible to use the chip to…
naught101
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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 brightness over the time). Example: LED1…
tigrou
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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 OUTPUT-HIGH? Current will then flow through…
Stephen Melvin
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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 some sort, I keep isolating lines, that is, the…
Chris B. Behrens
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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 plexing and understand that it will enable me to…
Rick_2047
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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 at a time as budget allows. Each module will…
captncraig
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How can this MOSFET steer the current of this LED driver?

I am powering a Charlieplexed LED array with this current source as shown in the first picture attached: One requirement was to be able to control the current so I decided to insert an array of MOSFETS that allowed me to control the current through…
Smart_Celery
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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 there a way to incorporate transistors into a…
JYelton
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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 of diodes/other elements I need. The controller…
AJMansfield
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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 displays in a charlieplex configuration with 8…
NotoriousDonkey
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