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.
242 questions
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Driving a LED matrix with TPIC6B595 as sink and UDN2981A as current source
I am working with an 8x6 RGB LED matrix with common cathode LEDs on a PCB. I can select one column at a time by grounding its common cathode, and I source the current through the rows. The whole setup ...
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Identification of pinout on LED matrix display
First thing first. I'm a beginner at electronics, but I have an LED panel I want to use for a esp32 project. The last couple of days I have been researching for at way to connect to this panel but ...
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How to stop ghosting while multiplexing LED matrix?
I tried to make a 4*4 LED matrix and controlling it with an Arduino. With certain LED patterns ghosting occurs. On each row, the LED anodes are connected together and each row goes (from top to bottom)...
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Why there is only few multi channel high side drivers (like 8 and more) (example. TD62783AP)
I'm Currently working on a LED matrix project(5 row x 15 column) using some AVR with shift register (74HC595 to multiplexing outputs) and some low-side drivers (ULN2003A as switch to GND) and hight-...
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Why are bipolar power supplies preferred for use with OLED?
Does anyone know what are the reasons that bipolar power supplies are preferred for use with OLED?
(ELVDD is a positive voltage and ELVSS is a negative voltage)
Image source: https://eureka.patsnap....
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How can I avoid current excursion in P-channel MOSFET (high side) and BJT (low side) led matrix driver?
How can I avoid current excursion in combination of P-channel MOSFET (high side) and BJT (low side) led matrix driver? I have poor understanding of what causes the excursion and how to address it.
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Voltage drop due to traces on LED matrix PCB
Basically, does the LED matrix PCB board below have a chance to work? If not, how can it be modified to have a chance to work?
The concern is the voltage drop along the row traces. Each row must carry ...
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How to apply a thermistor to my LED driver (TLC59116 PW package)
I currently use a TLC 59116 16-channel I2C LED driver in a 4 x 4 LED array driven by Arduino and would like to add a thermistor to the circuit design. I'm unsure where to add it or what supporting ...
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What is the point of two enable signals in PT6957 LED driver?
I have a 48 x 16 matrix LED display E-MOTIVE Q-B-069B (no datasheet), and during reverse engineering I found 4 off PT6957 there.
PT6957 is 16-bit shift register, latched with constant current drives. ...
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Why am I measuring 1e6 ohm forward resistance on a functioning LED? [duplicate]
I have an LED board with a busted driver, so I thought I'd probe the LEDs to determine a good replacement driver. If I probe the LEDs I don't get a readout on the voltage drop but the LEDs light up ...
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Troubleshooting a HT16K33 + 14 segment LED showing segments when not addressed
I'm working with a board that has multiple 14 & 7 segment displays all being addressed using an HT16K33 where various segments are either not displaying or are being lit when they shouldn't.
In ...
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PWM vs mutiplexing, why one can control the apparent brightness and other saves power?
In an LED grid where we are using multiplexing to control a ton of LEDs, where we are scanning each row quickly and using persistence of vision to enjoy the full picture at once; let's say that there ...
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RGB LEDs indvidual brightness control [closed]
i want to make RGB LEDs panel using https://www.lcsc.com/product-detail/Light-Emitting-Diodes-LED_TCWIN-TC5050RGBF08-3CJH-P35C_C784539.html RGB LEDs. I will put 100 LEDs in tha panel and want to ...
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Trying to overdrive LEDs my power supply amperage mysteriously "backs off"
I have a 48 parallel matrix of 3v LEDs. I'm trying to overdrive it. I set my supply to 3v and 0.5amps and the display glows. Up the amperage to say 1amp it gets brighter. So far so good. I keep ...
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Eliminating Noise from Audio Amp Board Input
I made this project by shajeeb (linked below), and I am having trouble with noisy ground lines. The circuit I made is the same as the diagram below except for where I connect the speaker and amplifier ...
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MAX7221 with multiple LEDs per point
I am using a MAX7219/MAX7221 chip in a keyboard design in order to light up the individual keys. The keyboard is going to have exactly 64 keys so with the 8x8 matrix the chip handles I will be able to ...
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LEDs in parallel with low voltage input source [closed]
Could you please help me understand below circuit in detail. What could be the voltage at testpointA if LED forward voltage drop is 2V?
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Replica Board of Samsung Horticulture Gen2 Module
I want to make Replica board of Samsung Horticulture Gen2 Module but with smaller form factor.
I am using 42× LM301H (Full spectrum) and 8× LM351H LEDs.
IF of LM301H is 65 mA and IF of LH351H is 350 ...
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How do pixels conserve their state? [closed]
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 ...
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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 ...
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Determining Power Supply Requirements for an 8x4 Grid Display of Chained 32x64 Pixel LED Matrices
I am planning to build an 8x4 grid display using chained 32x64 pixel LED matrices driven by a Raspberry Pi, and I've found mixed information online about the power supply required for such a setup. ...
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Control of 5*5 LED individually with 10 pins
I would like to embroider with electroconductive yarn and I need to light up 25 LEDs but they should work individually (not light up at the same time) and I can use only 10 pins. I cannot use any ...
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Design using 64 SK6812 LEDs - Matrix vs 8x8 matrix
I am designing a 64 LED ring and am curious about the advantages of a matrix design for addressable LEDs.
For example, if I want to use 64 SK6812s, what is the difference between connecting all of ...
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Who is the manufacturer of this LED array?
This is from a Cat6 tracer. It's an LED array and 3 of them have died.
I am looking to identify first who the manufacturer is and then who might be selling it.
When I google it, there are too many ...
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Understand the circuit LED
Help me to understand the circuit
If I power up this circuit, what will happen? Will the LEDs glow or will they be damaged?
LED datasheet link -EAHC2835WD6
LED Lighting - White, Cool 6500K 3.1V 150mA ...
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Mystery LED modules [closed]
I purchased some 50W LED lamps intended for outdoor use. Each module has 70 LED chips, so I suppose they are about 700mW each.
To my surprise they turn out to be pulsed and hence no use for video ...
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HT16K33 alternative for common anode?
I'm trying to drive a common cathode 8x8 bicolor LED matrix (1088AHG) with an HT16K33. However, the seller made a mistake and send me a 1088BHG which is common anode. Later the seller send me a right ...
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RGB matrix 32x16 connected to ESP32 shows only upper half part
I have
32x16 RGB matrix
ESP32 WROOM-32
Power supply for the matrix 5V, 5A
I used this guide to connect them. I just changed some wires. Here is my connection:
In text:
Upper RGB Data
R1 - G25
G1 - ...
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Most efficient and cheapest way to drive a high power and consumption giant dimming LED matrix
I'm building a giant LED matrix for an art project.
Each "pixel" is a 12V RGB LED strip consuming ~23W, and has to be fully dimming controllable.
We're talking about 768 pixels with a total ...
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Best approach to driving custom RGB mechanical keyboard LEDs
I am in the middle of designing a custom mechanical keyboard and have just finished the PCB schematic, but before I spend a few hours placing and routing components, I thought I might ask y'all a few ...
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Ghosting in LED Matrix
Some LEDs light up even if they are not supposed to. The LEDS should spell ECE on the right extreme of the pot, while 3-1 in the left extreme of the pot. So there are two scenarios, either show ECE or ...
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LED Matrix design in Multisim does not work in Tinkercad
We have this design in multisim and it works fine, the intended LEDs works fine in mutisim but when we used tinkercad to simulate, it does not work the same way. It is supposed to spell ECE (right ...
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SN74HC595 multiplexing with MOSFETs
I'd appreciate some advice on a basic circuit. I am using two SN74HC595 ICs to multiplex 64 LED groups, but I need different numbers of LEDs per group, and the total current draw for all the LEDs will ...
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How is this capacitance affecting other parts of the circuit?
I'm attempting to drive a matrix of LEDs. Columns. Rows. It flickers too much for my liking, so I tried smoothing the LEDs with capacitors, but I'm getting very odd behaviour.
Here is a minimal ...
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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 ...
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When do we need 1500 mA current to drive LEDs?
I saw an LED panel on Amazon with 50 LEDs, see picture. In the description they write that 3030 LEDs are used. I found in the datasheet that the maximum current is 250 mA for this type of LED.
I can't ...
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LED matrix 7x10
I am trying to assemble a 7 x 10 LED single-color matrix using 2 74HC595's for the 10 columns and a CD4017 for the 7 rows. Now obviously I am only going to use a total of 10 pins of the 74HC595 ...
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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" ...
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High Bay LED light rebuild
I've got a 200 W High Bay LED light from a friend. Its circuitry is blown up; it was connected to 380 V instead of 220 V, but it also had flickering issues before that.
I would like to build it a ...
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Powering a massive addressable LED project
So a two part question. I've built large scale LED projects in the past, but for the next one it would be massive (a black hole disc with a diameter of 54 ft), and addressable LEDs on the top and ...
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Resistor values for LED matrix
I am designing a binary coded watch with an attiny1616 MCU and an LED watchface. The matrix I designed is displayed below along with the rest of the schematic. The LEDs is 2.1V 30mA and I plan to ...
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Turn an LED on/off LED with a flip-flop counter [closed]
I want to make a 7x7 LED matrix which begins to turn on the first one LED to the last and then turns off the way back (spiral matrix.) I'm trying to turn the LEDs on/off by using signal created by ...
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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 ...
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Should I continue use daisy chaining or use another Chip Select PIN in MAX7219 8×8 LED matrix module to increase height dimension?
Consider I have 4 daised chaining of MX7219 LED Matrix 8×8. Thats mean i have more width than height (32×8) or (width×height)
If i want improve overal width of LED again, thats mean i must continue ...
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LED matrix power and multiplexing
I am trying to build a 7 character LED matrix (so 5x7 x 7 LEDs). I need it to be controllable from an ESP32 with Arduino code. So far what I've learned is that I need shift registers in order to ...
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Multiplex grid of LEDs with microcontroller
I'm trying to multiplex a grid of LEDs directly from a microcontroller but all the schematics I'm seeing online show how to multiplex to some kind of IC chip or board that isn't the main processor. I ...
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LED Matrix to reduce current consumption
I'm trying to control RGB LEDs via USB. All LEDs have the same color, so I'm controlling them with only 3 PWM signals (generated from a PIC).
The problem I'm facing is to reduce the current needed in ...
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How to use GPIO on STM32 (F103VET6) as a kind of of output battery?
After I learnt how to blink LEDs on the board, I came up with the idea of making a LED matrix.
The schematic is like this:
But I could not figure out how to light it!
Every LED can be lighted under 2....
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How many 2N2222 transistors required for 3x3 LED matrix to mutiplex
I have made a 3x3 LED matrix and was able to turn them on/off individually using an Arduino, but now I want to use an external 3 V instead of the Arduino pin voltage.
How many 2N2222 transistors are ...
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Help me identify pin of this LED Matrix PCB
LED Matrix bicolors (Orange/Green)
PCB board of 10 LED Matrix of 4 x 8 (LTP23548AA-NB)
It looks like J3 is regular UART|USB. I'm trying to find what J1 and J2 are about. The goal is to add a ...
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