Tagged Questions

1
vote
1answer
54 views

Multiplexing with or without transistors

I'm doing something in where I need to multiplex 6 7-segment displays. About doing it, I found things like this: And things in where the same thing is done without the transistors, just by ...
2
votes
1answer
97 views

Multiplexing large LED matrix

I have a project which involves building a 64 x 48 (3072) LED matrix driven by a Raspberry PI computer. I am a first-year computer engineering student so I am still inexperienced with shift registers ...
1
vote
2answers
64 views

Arduino multiplexing help needed.

Is it possible to use an 8 output demux to switch between seven 16 output demux's in the case that I want to control several LED's with an arduino uno? Is there a better way to do this?
3
votes
2answers
87 views

Is upping the voltage on a multiplexed LED display an appropriate response for dimness?

I have a 10 character x 16 segment display that I'm driving using multiplexing off a PIC. The problem is, however, that with each display only being on 1/10th of the time, the display appears much ...
1
vote
1answer
86 views

Maximum LEDs on a matrix

There are several methods to drive LEDs using a microcontroller. The easiest method is just connecting all LEDs to an own pin on the microcontroller. Say you have \$n\$ pins available, you'll be able ...
1
vote
2answers
299 views

Multiplexing an 8x8 Matrix - Why Transistors?

I'm trying to understand how to properly multiplex an 8x8 matrix (or any large amount of LEDs) http://arduino.cc/en/Tutorial/RowColumnScanning However, I'm getting a bit confused, since I've found ...
8
votes
2answers
412 views

LED Multiplex Anode-Row Driver

I'm helping build this art installation that amounts to a large 16 x 16 pixel display. I settled on using 16 TI TLC5926 constant current driver chips chained together to give me direct drive to each ...
6
votes
3answers
904 views

Miniature Traffic Light with Raspberry Pi: Wiring many LEDs

Background: I am a Civil Engineer specialized in traffic control devices and I have a small hobby project to build a scale model traffic light system. I can manage and control the traffic light ...
6
votes
3answers
569 views

Best way to control 130 - 140 LEDS with Arduino Uno 32/64 bit led drivers?

I am new to electronic prototyping and had a few questions. I need to control 132 LEDs individually. I want to make 3 rows ( 2 rows of 60 and 1 row of 12) I think i can matrix them but i would still ...
2
votes
5answers
984 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 ...
5
votes
2answers
449 views

How can I use one microcontroller to increment/decrement 4 sets of LEDs using 8 push button inputs?

I want to design a very small project for a portable score keeper. It consists of using one microcontroller to control 4 sets/groups of LEDs on a small PCB. It is a very small scale project (3.5in X ...
1
vote
2answers
600 views

Simple solution for driving a large-ish RGB LED array with PWM

I'm working on a small toy-like device that has a 10 x 8 "pixel" array of RGB LEDs at its core; thus there are 10 x 8 x 3 = 240 individual LEDs to be controlled. I'd like to control the intensity of ...
7
votes
6answers
589 views

Controlling 5000 LED

I'm doing a project where it requires to control 10,000 I/O. 5000 output - For 5000 LED, where only 1 LED will be light up at one time 5000 input - For 5000 sensor, where it'll sense the presence of ...
4
votes
3answers
3k views

Multiplexing LEDS and Multiple Output Pins

Ok.....i've been trying to understand something (and trust me, to most people it's a VERY newbish question) So I see people all the time "multiplexing" LEDS. using just a few Pins. Lets say for an ...
6
votes
5answers
5k views

How can I control many LED's with just a few pins on my micro?

I am using an Atmel ATTINY13 which has a 6-pin I/O. I'd like to control about 15 LED's but am unsure how to connect everything. Without multiplexing of any sort, it seems I'd only be able to control 6 ...
1
vote
2answers
250 views

Why is my code running so slow?

Hey guys. I'm building a 9 RGB LED chaser, using an ATTiny2313 to drive it. The cathodes are connected to all of PORTB and pin 6 of PORTD. I wrote some code to drive them all, but for some reason it's ...
7
votes
9answers
1k views

Serial control of 25 LEDs from a single pin

I have a microcontroller with one available digital pin. How can I control 25 LEDs?
14
votes
2answers
2k 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 ...
2
votes
4answers
1k views

What to use for the high-side (anode) drivers of a common anode LED matrix?

I'd like to multiplex rows of LEDs with a constant current sink driver. Should I just use BJTs to switch current into the rows of anodes, or is it better to use FETs, an array of FETs, or the same ...
15
votes
14answers
9k views

Controlling 500 LEDs with PWM

I'm considering taking on a project that would involve individually addressing 500 LEDs, optimally with PWM support for each. I'm planning on using an Arduino since I already have one, but I'm open ...