Individually addressing LEDs strip via ws2811 on arduino uno with FastLED lib

Other Hardware LEDs and Multiplexing
1

Hi there, i want to light one of three LEDs in my led-strip, while keeping the others turned off. Right now i can only get the same color for each of the LEDs.

The ledstrip is a worldsemi RGB led strip with GND, DIN and 12v.
I am using the library fastLed for arduino and i am running the code from their own example, as seen below.

As said, i CAN light all of the LEDs in one color, however I CANNOT light them individually.

Thanks!

// Use if you want to force the software SPI subsystem to be used for some reason (generally, you don't)
// #define FASTLED_FORCE_SOFTWARE_SPI
// Use if you want to force non-accelerated pin access (hint: you really don't, it breaks lots of things)
// #define FASTLED_FORCE_SOFTWARE_SPI
// #define FASTLED_FORCE_SOFTWARE_PINS
#include "FastLED.h"

///////////////////////////////////////////////////////////////////////////////////////////
//
// Move a white dot along the strip of leds.  This program simply shows how to configure the leds,
// and then how to turn a single pixel white and then off, moving down the line of pixels.
// 

// How many leds are in the strip?
#define NUM_LEDS 3

// Data pin that led data will be written out over
#define DATA_PIN 6

// Clock pin only needed for SPI based chipsets when not using hardware SPI
//#define CLOCK_PIN 8

// This is an array of leds.  One item for each led in your strip.
CRGB leds[NUM_LEDS];

void setup() {
	// sanity check delay - allows reprogramming if accidently blowing power w/leds
   	delay(2000);
      // FastLED.addLeds<WS2811, DATA_PIN, RGB>(leds, NUM_LEDS);

}

// your leds.
void loop() {
      leds[0] = CRGB::Red;
      leds[1] = CRGB::Black;
      leds[2] = CRGB::Black;
      FastLED.show();

}
2

On this line

      // FastLED.addLeds<WS2811, DATA_PIN, RGB>(leds, NUM_LEDS);

The two slashes indicate that the line is "commented out" and ignored/not executed. That line is essential for the FastLED library to work.

3

Hm, i just uncommented the line (which i have done before, just forgot this time)
Im still having the same problem.

4

Dang, thought I had it there!

So using the above sketch with the addLeds line included, all three leds light up red?

5

Have you wired everything up correctly? How we know you know what 'correctly' means unless you actually show us what you've done?
Try putting a:

FastLED.clear();

as the last line in your setup().

And don't bother with
leds[1] = CRGB::Black;
leds[2] = CRGB::Black;

just work 1 led at a time until you know it's working as you think it does

6

I am having the same issue. I have modified the FastLED code for the correct color and pin and the suggestion above for the FastLED.Clear(); command, otherwise it is the same example code that came in the library, RGBCalibrate. My library is version 3.1.3. Here is what it is doing:

#include "FastLED.h"


////////////////////////////////////////////////////////////////////////////////////////////////////
//
// RGB Calibration code
//
// Use this sketch to determine what the RGB ordering for your chipset should be.  Steps for setting up to use:

// * Uncomment the line in setup that corresponds to the LED chipset that you are using.  (Note that they
//   all explicitly specify the RGB order as RGB)
// * Define DATA_PIN to the pin that data is connected to.
// * (Optional) if using software SPI for chipsets that are SPI based, define CLOCK_PIN to the clock pin
// * Compile/upload/run the sketch 

// You should see six leds on.  If the RGB ordering is correct, you should see 1 red led, 2 green 
// leds, and 3 blue leds.  If you see different colors, the count of each color tells you what the 
// position for that color in the rgb orering should be.  So, for example, if you see 1 Blue, and 2
// Red, and 3 Green leds then the rgb ordering should be BRG (Blue, Red, Green).  

// You can then test this ordering by setting the RGB ordering in the addLeds line below to the new ordering
// and it should come out correctly, 1 red, 2 green, and 3 blue.
//
//////////////////////////////////////////////////

#define NUM_LEDS 6

// Data pin that led data will be written out over
#define DATA_PIN 10
// Clock pin only needed for SPI based chipsets when not using hardware SPI
//#define CLOCK_PIN 8

CRGB leds[NUM_LEDS];

void setup() {
	// sanity check delay - allows reprogramming if accidently blowing power w/leds
   	delay(2000);

      // Uncomment one of the following lines for your leds arrangement.
      // FastLED.addLeds<TM1803, DATA_PIN, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<TM1804, DATA_PIN, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<TM1809, DATA_PIN, RGB>(leds, NUM_LEDS);
       FastLED.addLeds<WS2811, DATA_PIN, BRG>(leds, NUM_LEDS);
      // FastLED.addLeds<WS2812, DATA_PIN, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<WS2812B, DATA_PIN, GRB>(leds, NUM_LEDS);
      // FastLED.setBrightness(CRGB(255,255,255));
      // FastLED.addLeds<GW6205, DATA_PIN, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<GW6205_400, DATA_PIN, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<UCS1903, DATA_PIN, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<UCS1903B, DATA_PIN, RGB>(leds, NUM_LEDS);

      // FastLED.addLeds<WS2801, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<SM16716, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<LPD8806, 9, 10, RGB>(leds, NUM_LEDS);

      // FastLED.addLeds<WS2801, DATA_PIN, CLOCK_PIN, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<SM16716, DATA_PIN, CLOCK_PIN, RGB>(leds, NUM_LEDS);
      // FastLED.addLeds<LPD8806, DATA_PIN, CLOCK_PIN, RGB>(leds, NUM_LEDS);

      FastLED.clear();
}

void loop() {
   leds[0] = CRGB(255,0,0); 
   leds[1] = CRGB(0,255,0);
   leds[2] = CRGB(0,255,0);
   leds[3] = CRGB(0,0,255);
   leds[4] = CRGB(0,0,255);
   leds[5] = CRGB(0,0,255);
   FastLED.show();
   delay(1000);
}
7

I just realized that there is one WS2811 IC for every 3 leds which is why I am seeing this effect. Perhaps the OP had the same issue. Watch out when you are buying these strips!