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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.

232 questions
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Multiplexed LED matrix resistors

I'm trying to build this multiplexed LED matrix with 216 LEDs, NPN transistors, a PIC microcontroller and several shift registers (74hc595) , however I don't know how to calculate the value of the resistors that are connected to the anodes, and also…
Jaime Centeno
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How do pixels conserve their state?

How do LEDs conserve their state? I'm pretty sure each LED is powered thanks to decoders, but decoders cannot keep a steady power flow through each; every cycle can only light one LED. But once the cycle moves on, how does this led preserve it's…
qkasriel
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LED matrix display - outdoor

In my application the user needs to read a few simple shapes and characters under the bright sunlight. In terms of visibility, what would be the ideal solution? I am basically looking for experience of previous implementors or some research on the…
Ktc
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How will current divide in a LED matrix in one select line when there are 8 data lines?

simulate this circuit – Schematic created using CircuitLab Let's say I have a select line that is connected to 8 data lines in an LED matrix. The current at the drain of the MOSFET is 800mA. Will the current divide among the 8 LEDs into 100mA for…
NaP
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LED Matrix Design

I have a LED arrays designed on Aluminium heatsink PCB. I have SMD White LEDs whose specs are as follows and differ from already existing LEDs mounted on PCB :- Forward Current : 60mA and Max. 90mA Wattage : 0.2W Link to Datasheet of LED :-…
MICRO
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Does anyone have the datasheet for this display?

Does anyone have the datasheet for this display there is no serial number or Ebay link. A student came to me with this 4 digit 7 segment LED, there are 12 pins in one side, and nothing on the other side. Model number is, WP02841MGA.
narzan
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LEDs in parallel with low voltage input source

Could you please help me understand below circuit in detail. What could be the voltage at testpointA if LED forward voltage drop is 2V?
Micro
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Looking for a simple LED direction-type of circuit using leds and resistors--or other?

I'm looking for a very simple circuit, but for the life of me (and my old age!) I cannot find something that I'm able to make work for this project and would like some input from you folks. I'm looking to build an antenna rotator direction circuit,…
Chris Clement
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Do I need a resistor to connect this LED lamp?

I purchased this LED lamp on Aliexpress, the spec says it's 36V, 20W. I want to know how to connect it to my ebike 36V battery, in particular can I connect it directly or I need a resistor? I tried connecting it with a 2K resistor and it works,…
exebook
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Incorrect wiring for a DIY LED matrix?

I'm trying to get a home made LED matrix to show a rainbow pattern coming from the bottom up but it's playing this bizarre, dancing pattern. The matrix is in series, with 4X WS2811 addressable LED strips and is 600 LEDs total. 12 horizontal, 51…
lakerice
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LED panel refresh rate and scan rate (multiplexing) relationship

Considering high-end panel as ROE Ruby 2.3 https://www.roevisual.nl/uploads/bestanden/ruby-r2.3-brochure-lr-v12020.pdf the scan rate (multiplexing) is \$s=1/12\$ and refresh rate is \$f=1920\$ Hz. What does the refresh rate mean? Does it mean how…
Filip
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LED Christmas lights without limiting resistor

My LED Christmas light strings do not have a series limiting resistor, how is this achieved? They are 70 LED strings with two 35 bulb sections. I have carefully checked and there are no provisions in the plug or inline with the wire. I measured…
D. Elttub
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Level translator for led matrix

What is the best way to make a level translator for a led matrix? I have an mcu port 3,3V 5mA and I want to replace the leds with higher voltage and current, 24V 50mA for example This is my led array simulate this circuit – Schematic created using…
MrBit
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Can two MAX7219 chips drive a 10x11 LED matrix?

I want to drive a 11x10 LED matrix. Can two MAX7219 do this? Is there a way to have on MAX7219 handle a core of 8x8 LEDs and the other would drive the remaining 3 cols and 2 rows?
BlueSky
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Commond anode led driver

I need to drive a bunch of 7-segments and 14-segments led display (in total, 105 LEDs with common anode). I bought an HT16K33 to drive them, but did not take into account the common cathode requirement... I can't manage to find any chip that could…
Nicolas Appriou
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