40 votes
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Addressable RGB strip works fine individually but cannot set all LEDs to full white

I would suspect that it is a voltage drop in the power rails caused by the current draw. Probably cheap construction with copper tracks that are just too thin and so have too high a resistance. To ...
Majenko's user avatar
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8 votes
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How does an LED in an LED-strip like WS2811 know when it should be on or off

The WS2811 is the driver chip, that is embedded into the strip. In principle it is some kind of shift register, that outputs PWM values, and on the strip they are daisy-chained (data output of one is ...
chrisl's user avatar
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6 votes
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How do I control the onboard LEDs of my Arduino Nano 33 BLE Sense?

There are 3 LEDS on the Nano 33 BLE: A power LED on pin 25 (yes, you can turn off the power LED programmatically); A built-in LED on pin 13; An RGB LED with red on pin 22, green on pin 23, and blue ...
ocrdu's user avatar
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5 votes
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Adafruit Neopixel Library- only the first 16 LEDs respond

When something works, but not completely, it's often due to power issues. Embedded things, microcontrollers/Arduino are fairly robust and "logical". Hence, if your Arduino program works today, it'll ...
aaa's user avatar
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5 votes
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How to connect a 12V power supply to an RGB LED strip receiving RGB values via Arduino Uno PWM pins?

01) Is the above diagram safe and sound? It looks to be OK, except one thing: The current you can draw from the Arduino's VIN pin is limited to about 1A. That is a sixth of what your power supply ...
Majenko's user avatar
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5 votes
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RGB LED Resistance

The problem with one resistor in common anode/cathode is that when you activate more than one colour of the RGB LED, you will have additional current flowing through the one resistor which will cause ...
BartmanEH's user avatar
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5 votes
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How to use a common anode 7-segment, 4-digit display?

Just as a complement to Paul's answer, I wrote a short program to show how to drive the 7-segment 4-digit display of his figure: This is actually a common cathode display, so the program assumes that,...
Edgar Bonet's user avatar
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5 votes

How to use a common anode 7-segment, 4-digit display?

I'll try and take you through the complete basics of LED's etc. As 4-digit 7-segment displays are a combination of multiple "LED techniques". Wiring LED's LED's, or Light Emitting Diodes, are one of ...
aaa's user avatar
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5 votes

RGBW LED strip: which components are required?

NeoPixels The strips based on the WS2812 / SK6812 and similar chips, known by some as NeoPixels, are clever ways of implementing fully-addressable 24-bit colour LEDs. One of the clever things is ...
Nick Gammon's user avatar
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How do I turn off a 12V 3A RGB LED strip?

That's pretty simple: when you turn off all the colours you are actually turning off the entire strip with very minimum leakage current in each of the three FETs.
Roberto Lo Giacco's user avatar
5 votes
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Setting 10 RGB Strips Independently from Single Arduino

You could use chainable RGB drivers like these: They are based on the P9813 chip and can be used with the FastLED library. You can find them on Aliexpress or eBay, if you search for "STM32 rgb". ...
gre_gor's user avatar
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5 votes

How does an LED in an LED-strip like WS2811 know when it should be on or off

The LED units don't have any unique addresses of their own, instead they are indexed by their position in the string of LEDs. When you feed data into the first LED, you put the entire sequence of ...
vurp0's user avatar
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5 votes
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FastLED: Can't address led individually

The description in the link of where you bought the strip says: Description: LED Type: 5050SMD with External IC WS2811 (1 IC control 3leds) So, this is probably as intended. Note the ...
jose can u c's user avatar
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5 votes

Addressable RGB strip works fine individually but cannot set all LEDs to full white

Majenko's answer is correct, and you could also verify it with the test performed. Since it is an issue I encountered myself in the past in a similar case, I want to share some measurements I took on ...
frarugi87's user avatar
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4 votes
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Controlling a digital 12V addressable RGB led strip with Arduino?

The only signal you need to worry about is DIN (data in) which is normally 5V from an Arduino. Use that to switch a MOSFET or transistor to convert the digital pulses to 12V. In other words, the ...
Nick Gammon's user avatar
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4 votes
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Fading LED Lights

You could look at this example, which fades an LED using PWM. https://www.arduino.cc/en/Tutorial/Fading Basically you use analogWrite to control the output of the pins with finer resolution, 0-255 ...
Code Gorilla's user avatar
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4 votes

Directly powering a single 32x16 RGB LED matrix (without external PSU)

When powered through USB, the total current consumption is limited to 500mA by the USB interface. If you are using the power connector, the total current is limited by the on board 5V regulator to 1A. ...
Fauzan's user avatar
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4 votes
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RGB LED strip 100m

100 Meters of 5050 SMD strip LEDs will require roughly 120-200 amps. However, you cannot drive a 100 meter strip from a single power supply. The thin copper traces in the LED strip can only handle so ...
AJ_Smoothie's user avatar
4 votes
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What can I do to increase the amount of LEDs I can power with a pro micro?

As Majenko already mention, use a separate power supply. Use that power to power the LED strip(s). Use the MCU to control the data and clock lines. Connect grounds together.
Michel Keijzers's user avatar
4 votes
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WS2812B are only white on custom board

The WS2812B chips are very sensitive to timing. They rely on pulses being just the right length for things to work. It is common if the timing is off that you just end up with white. Since you have a ...
Majenko's user avatar
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3 votes

RGBW LED strip: which components are required?

I like the ws2812 RGB LEDs with integrated controller. They can be found on adafruit.com, e.g. here: Adafruit NeoPixel NeoMatrix 8x8. There are some good tutorials on adafruit.com: https://learn....
bastelflp's user avatar
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3 votes

Adafruit Neopixel Library- only the first 16 LEDs respond

You don't modify the library at all. The page refers to the constructor which is the last line here: #include <Adafruit_NeoPixel.h> #define PIN 6 Adafruit_NeoPixel strip = Adafruit_NeoPixel(...
Nick Gammon's user avatar
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3 votes

Audio Input into A0?

Depending on how loud your audio signal is, you may be able to do it with just one capacitor and two resistors: If your signal is quite quiet, though, you may need to amplify it using an op-amp. For ...
Majenko's user avatar
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3 votes

How many WS2811 LED strips can I control with Arduino?

There are three factors to consider when driving strings of these LEDs from an Arduino: How much memory the Arduino has - each LED takes at least 3 bytes of RAM (possibly more depending on the ...
Majenko's user avatar
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3 votes
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Whats wrong with my code?

The errors are self-explanatory. You just have to read them carefully. ‘B54A3AC5’ was not declared in this scope The compiler doesn't know what "B54A3AC5" means. Nor do I, but I gess you may mean ...
Edgar Bonet's user avatar
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3 votes
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Is there a way to put multiple integers in a method?

Check your spelling Intensity instead of Intesity. Consider using switch instead of if-then-else. Define left, right and middle as [integer] constants somewhere (and probably something more ...
AJD's user avatar
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3 votes

Wearable GPS LED help

I think others have addressed the need for you to modify the strip colors based on distance or bearing or... whatever you want to show. Here's a NeoGPS version of that sketch. I think it may be ...
slash-dev's user avatar
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3 votes

TLC5917 Electrical Characteristics

The concepts of HIGH and LOW, and thus the voltages associated with those concepts, apply only to logic signals. LED drivers are not logic signals - they are constant current sinks. The voltages you ...
Majenko's user avatar
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3 votes

for() loop doesn't seem to break?

Consider the sequence of values of "fadeIn". It starts at 8 and in incremented by 16. So: 8, 24, ... 248, 264, ... . It is never exactly 255. So you never break out of your "for" loop. There is ...
st2000's user avatar
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3 votes
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Unexplainable int behavior in encoder/LED project

Here: CRGB leds[NUM_LEDS]; you are defining an array of NUM_LEDS objects of the CRGB type. Valid indices for this array range from 0 to NUM_LEDS-1. Here: for (int i = 0; i <= NUM_LEDS; i++) { ...
Edgar Bonet's user avatar
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