Electrical Engineering Stack Exchange
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Questions tagged [led-matrix]

Anything related to LED matrices. A LED matrix is a rectangular arrangement of LEDs where all LEDs in a row have their cathode (or anode) connected to the same line and all LEDs in a column have their anode (or cathode) connected to the same line. In this way a single LED can be lit supplying power to the lines corresponding to its row and column coordinates.

Anything related to LED matrices.

A LED matrix is a rectangular arrangement of LEDs where all LEDs in a row have their cathode (or anode) connected to the same line and all LEDs in a column have their anode (or cathode) connected to the same line. In this way a single LED can be lit supplying power to the lines corresponding to its row and column coordinates.

See also this tutorial on how a LED matrix work.

227 questions
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Reliability problems with an array of 91 high-power LEDs

I have designed and printed a 4-layer PCB that accommodates 91 infrared LEDs in a 7x13 rectangular layout. This will be used as a backlight for a machine vision project. I am having a problem where individual LEDs are burning out or perhaps becoming…
cxrodgers
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How to connect LED Matrix into Arduino using MAX 7219?

I have: 2 8x8 LED Matrix, and a MAX7219 Chip. Q: I just wonder how can I connect that to the Arduino Duemilanove? I have been googling but I couldn't find out how.
Vic
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Grayscale using LED

If I took a regular LED that is either on or off, the brightness of which can be controlled by the amount of voltage it's getting, then at half power I could in theory get a 3rd "shade" which could be used to make some cool effects. Is there a white…
Chadley123
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Why does a 74HC595N work in LED matrices?

I have checked a lot of LED matrices, and mostly a 74HC595N shift register is used. In some cases a TPIC595B like below. Example: Driving LED arrays with Arduino Circuit from above example: I understand that for sinking a TPIC is needed, because…
Michel Keijzers
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Can I replace these many capacitors with just one?

I'm designing a schematic for an addressable RGB LEDs array and I've chosen the WS2812B because of how common and cheap they are. Looking at the typical application circuit, I noticed there is a capacitor for each LED. Can the multiple capacitors…
prenone
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How is the current limited through the LEDs in this LED matrix design?

I was studying some LED matrix designs on the Net and came across the one below: DMD: Dot Matrix Display 32x16 (link to product) (somewhat poorly drawn) schematics of an old version of the product. Its design puzzled me because I couldn't tell…
Ricardo
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Is the there an intended PCB layout for the MAX7219/MAX7221 I'm missing?

The ordering of the segment pins (14-17, 20-23) on the MAX7219/MAX7221 common-cathode LED display driver is unusual, to say the least: The order of these pins is similar, but not identical, to the standard pin layout used by 4-position 7-segment…
user39382
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Reading corresponding pins from a circuit diagram

I am completely new to Arduino tinkering and am trying to make sense on how to wire a 8x8 LED matrix using the following diagram: This chart is supposed to correspond to this 8x8 LED, 12x12pin LED matrix: Now, the question: The physical led…
krystah
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Is it a good idea to refresh a display (8x8 LED matrix in this case) inside an interrupt handler?

Let's say I have an Arduino connected to a 8x8 LED matrix. In my case, the LED matrix is driven using two 74HC595 shift registers (one for the rows and one for the columns). Since it can only set the status of 8 LEDs at a time (one row), idea is to…
tigrou
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Running MAX7219 at 3.3v with ESP8266?

I just got a 4 chained 8x8 LED max7219 displays with a 5 pinout, these are very popular https://www.amazon.com/Wangdd22-MAX7219-Arduino-Microcontroller-Display/dp/B01EJ1AFW8/ref=sr_1_5?s=books&ie=UTF8&qid=1520880134&sr=8-5&keywords=MAX7219 I've…
Dani
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How to separate the schematic of a RGB LED into 3 individual LEDs in Altium?

I'm designing a RGB LED matrix with the following footprint: Which has the following schematic: It's just a combination of three LEDs in one component. In my matrix design, I need to wire the individual LEDs to avoid ghosting. Thus the LEDs on the…
Rix
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Is advisable to drive an LED matrix using a Shift Register+FET on High side and an LED driver on the low side?

Trying to find the most economical way to drive 60 leds (~20mA) for volume production. Our main MCU doesn't have enough pins, so I2C or similar set up is needed and total budget of driving LEDS should be under $1. Best I came up with is a…
MandoMando
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How Many LEDs can be driven with one WS2811

I am starting a project and will be using WS2811 LED drivers to create a large matrix (about 40 to 50 panels) with a micro controller (Arduino compatible). I already purchased and received the RGB LED strips. They are the 5050 Type and have 30 LEDs…
DMilton2004
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Uniformly illuminate an array of LEDs: how to get the most homogeneous output?

Please note: this question refers to the electrical engineering part of the design, optical configuration is not request (advices are however welcome) I'm trying to design a LEDs lamp with an homogeneous output for a radiometric experiment (so I…
G M
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RS232 LED matrix programming

I managed to pick up two 16x64 unbranded LED matrix for next to nothing. My son has autism and absolutely loves LED scrolling signs so I thought it would be a nice project to build for him. They have USB and serial wires. USB only does power I…
d0little
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