Interfacing WS8211 RGB LED Strip with Arduino: Step by Step Tutorial

Welcome to our blog post on interfacing the WS2811 (5V) RGB LED strip with Arduino! In this guide, we will walk you through the process of connecting and controlling WS2811 LED strips using an Arduino microcontroller. WS2811 LED strips are popular due to their individually addressable RGB LEDs, allowing for captivating lighting effects in various projects, including home decor, art installations, and DIY electronics. Here is the previous project where we built a fun LED Arcade Game using WS2811 RGB LED strip.

In this blog post, we will cover the essential steps involved in setting up the hardware and software for your WS2811 LED strip. We'll explain the necessary connections between the LED strip, Arduino board, and power supply, along with the software libraries required to control the LEDs. Additionally, we will provide sample code snippets and explanations to help you get started quickly.

What is a WS2811 RGB LED Strip?

The WS2811 LED Strip is an individually addressable RGB LED strip which allows control over each LED independently using a single data line. RGB LED stands for Red, Green, and Blue Light-Emitting Diode. The WS2811 RGB LED consists of three LEDs all in one package, where each LED is capable of emitting red, green, or blue light independently.

WS2811 vs Other LED Strips Comparison

Feature	WS2811	WS2812	Standard RGB Strip
Individual Control	Yes	Yes	No
Voltage	5V	5V	12V/24V
Data Lines Required	1	1	3 (RGB)
Arduino Pins Used	1 Digital Pin	1 Digital Pin	3 PWM Pins

 

Hardware Setup

RGB LED stands for Red, Green, and Blue Light-Emitting Diode. It is a type of LED that contains three individual LEDs in a single package, with each LED capable of emitting red, green, or blue light independently. By combining different intensities of these primary colours, an RGB LED can produce a wide range of colours, including a full spectrum of hues.

RGB LED Pinout

Anode Connection: The longest pin of the common anode RGB LED is the anode (+) pin. It is connected to a positive voltage supply, typically 5V. This anode pin is shared among all three colour LEDs.

Cathode Connection: There are three shorter pins, each representing the cathode (-) connection of the individual colour LEDs (red, green, and blue). These cathode pins are independent and not connected.

 

Types of RGB LED

There are three main types of RGB LEDs

Common Anode RGB LED: In this type, the anode (+) terminal of the red, green, and blue LEDs is connected and shared as the common pin. Each cathode (-) terminal of the individual LEDs is connected to a separate pin. To light up a specific colour, the common pin is connected to a positive voltage, and the desired LED cathodes are connected to ground (GND) through appropriate resistors.

Common Cathode RGB LED: In this type, the cathode (-) terminal of the red, green, and blue LEDs is connected and shared as the common pin. Each anode (+) terminal of the individual LEDs is connected to a separate pin. To light up a specific colour, the common pin is connected to ground (GND), and the desired LED anodes are connected to a positive voltage through appropriate resistors.

Addressable RGB LED: Also known as individually addressable or digital RGB LED, this type incorporates built-in ICs (Integrated Circuits) within each LED package. These ICs allow each LED to be controlled independently, making it possible to create complex lighting effects and patterns. Addressable RGB LEDs are typically controlled via a data line, such as the WS2811, WS2812, or APA102 protocols.

RGB LED Working

Controlling Colours: To light up a specific colour, you need to create a current path from the common anode (+) to the desired cathode pins (R, G, B). By connecting the cathode pins to the ground (GND) through appropriate current-limiting resistors, you can control the intensity of each colour LED.

To turn on the red LED, you would connect the cathode of the red LED (R) to ground (GND) by activating the corresponding GPIO pin of your microcontroller or Arduino.

Similarly, you can control the green LED (G) and blue LED (B) by connecting their respective cathode pins to ground (GND) through GPIO pins.

Colour Mixing: By adjusting the intensity of each colour LED, you can create different colour combinations. Varying the current flowing through each cathode pin allows you to mix different levels of red, green, and blue light, resulting in a wide range of colours.

For example, if you want to create a purple colour, you would activate the red (R) and blue (B) LEDs by connecting their cathodes to ground (GND) while keeping the green (G) LED inactive.

By controlling the on/off state and intensity of each cathode connection, you can achieve different colours, including white (all three LEDs on), different shades of red, green, and blue, and various combinations in between.

Arduino WS2811 Interfacing Wiring Diagram

GND This pin connects to the ground (GND) or 0V reference of the power supply.

DATA This pin is the data input for the WS2811 driver. It receives the control data from the microcontroller or Arduino, usually through a digital output pin.

VCC This pin connects to the positive supply voltage (VCC) of the power source. The WS2811 typically operates at 5V, so this pin is usually connected to the +5V power supply.

R-OUT This pin is the output for the red colour channel of the addressable RGB LED. It is connected to the anode (+) of the red LED within the RGB LED package.

G-OUT This pin is the output for the green colour channel of the addressable RGB LED. It is connected to the anode (+) of the green LED within the RGB LED package.

B-OUT This pin is the output for the blue colour channel of the addressable RGB LED. It is connected to the anode (+) of the blue LED within the RGB LED package.

DOUT This pin is the data output for daisy-chaining multiple WS2811 ICs. It allows the control data to be passed on to the next WS2811 IC in the chain.

WS2811 Driver IC Pinout Explanation

Pin Name	Function	Arduino Connection
VCC	Power Supply (+5V)	External 5V Supply
GND	Ground (0V)	Arduino GND + Power Supply GND
DATA	Data Input	Digital Pin (Pin 5 recommended)
DOUT	Data Output (for chaining)	Next LED Strip DATA pin
R-OUT, G-OUT, B-OUT	RGB LED Outputs	Connected to RGB LED

Each WS2811 RGB LED draws about 60mA at full brightness (20mA per colour channel). If you are using an Arduino WS2811 with strips longer than 10 LEDs, you will need to use an external 5V power supply to prevent damage to your Arduino board.

Circuit Diagram of WS2811 Driver

In this circuit, a 5V power supply is used to provide a constant current output of approximately 18.5mA per output pin of the WS2811 driver. This ensures consistent luminescence and colour temperature of the RGB LED. A 104 (0.1µF) non-polarised capacitor acts as a bypass capacitor to filter AC components in the power rail. Two optional 33-ohm resistors match impedance at the data port. The circuit shows a common anode RGB LED configuration.

Working of WS2811 LED Driver

The WS2811 driver receives data in a specific format that represents the desired colour and intensity for each LED. The control data is sent serially, and each LED along the chain interprets its respective data segment to determine its colour output.

Each bit of data sent to the WS2811 driver consists of a high or low signal level that represents the colour intensity for a specific LED. The timing of these high and low levels is critical. The WS2811 uses specific durations to differentiate between a "0" and a "1" bit. For example, a short high pulse followed by a long low pulse might represent a "0" bit, while a long high pulse followed by a short low pulse might represent a "1" bit.

The WS2811 driver expects data to be transmitted in frames, where each frame consists of a series of bits representing the desired colours for all the connected LEDs. The timing between frames is important to separate one frame from the next and ensure proper synchronisation. Typically, a short low signal is used to indicate the end of one frame and the beginning of the next.

The WS2811 driver requires a reset pulse to initialise the data reception process. This reset pulse should have a duration longer than 50µs to ensure the WS2811 IC is in the proper state to start receiving the data.

The timing requirements of the WS2811 driver are quite stringent, and the signal timings need to be within specific tolerances for reliable operation. Timing deviations beyond these tolerances can lead to data corruption and inaccurate colour representation.

Colour Mixing: The WS2811 driver controls RGB (red, green, blue) addressable LEDs. To achieve different colours, the intensity of each colour channel is adjusted by adjusting the duty cycle of the PWM signal. By combining different levels of red, green, and blue, the driver can create a wide range of colours. For example, mixing full intensity of red and green results in yellow, while mixing full intensity of red and blue produces magenta.

PWM Control: PWM is a technique that modulates the width of pulses in a digital signal to control the average power or intensity of a corresponding output. The WS2811 driver uses PWM to control the brightness of each LED. It rapidly turns the LED on and off at a specific frequency, adjusting the duration of the "on" state (duty cycle) to control the perceived brightness. By varying the duty cycle of the PWM signal for each colour channel, the WS2811 driver can create different levels of intensity for red, green, and blue, allowing for precise colour control.

Parts of WS2811 LED

The basic circuit for WS2811 consists of the following components:

• WS2811 IC: The WS2811 chip itself is the heart of the circuit. It integrates the control circuitry and drive circuitry required to control the RGB LEDs.

• RGB LEDs: The WS2811 is designed to control RGB LEDs, which contain three separate LED elements: one for red, one for green, and one for blue. Each LED can be independently controlled to produce a wide range of colours.

The WS2811 ICs are daisy-chained, meaning the data output of one IC connects to the data input of the next IC, allowing for control of multiple LEDs in a sequential manner.

WS2811 LED Strip Pinout 

As you can see in the image, there is a male end and a female end. The female end can be connected to another male end, thus elongating the wire.

As much as you would like to elongate the wires to infinity by using only the Arduino, the Arduino’s voltage regulator will only allow a maximum current of 1A. So, we suggest using an external 5V power supply.

Circuit Diagram of Interfacing Arduino with WS2811 LED Strip

Connect the 5V power supply's positive terminal to the +5V pin of the WS2811 LED strip.

Connect the 5V power supply's negative terminal to the GND pin of the LED strip.

Connect the data pin of the LED strip to the digital pin 5 on the Arduino. Note the PIN for later use.

Software Setup & FastLED Library Installation

Installing FastLED Library for WS2811 Arduino Code:

Open the Arduino IDE and Install the FastLED library in the Arduino IDE (Sketch -> Include Library -> Manage Libraries -> Search for "FastLED" -> Install).

Copy and paste any Code from the ones given below and upload it to the Arduino Nano.

5 Amazing WS2811 Arduino Code Examples with FastLED

⇢ Code Example 1: LED Chaser Effect

This Arduino WS2811 interfacing programming example creates a beautiful chaser effect with bidirectional movement.

#include <FastLED.h>
#define LED_PIN 5    // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50  // Replace with the number of LEDs in your strip
#define DELAY_TIME 20  // Delay between LED movements (in milliseconds)
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  // Turn off all LEDs
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB::Black;
  }
  // Move the LED chaser
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB::Blue;  // Set the current LED to blue
    FastLED.show();  // Update the LED strip
    delay(DELAY_TIME);  // Delay between LED movements
  }
  // Move the LED chaser in reverse
  for (int i = NUM_LEDS - 1; i >= 0; i--) {
    leds[i] = CRGB::Green;  // Set the current LED to green
    FastLED.show();  // Update the LED strip
    delay(DELAY_TIME);  // Delay between LED movements
  }
}

⇢ Code Example 2: Rainbow Colour Cycle

Create stunning rainbow effects with this WS2811 Arduino code FastLED example.

#include <FastLED.h>
#define LED_PIN 5    // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50  // Replace with the number of LEDs in your strip
#define DELAY_TIME 50  // Delay between color changes (in milliseconds)
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  static uint8_t hue = 0;  // Hue value for color shifting
  // Set all LEDs to the current hue
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CHSV(hue, 255, 255);
  }
  FastLED.show();  // Update the LED strip
  delay(DELAY_TIME);  // Delay between color changes
  // Shift the hue for the next frame
  hue++;
}

⇢ Code Example 3: Breathing Effect

Create stunning rainbow effects with this WS2811 Arduino code FastLED example.

#include <FastLED.h>
#define LED_PIN 5       // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50      // Replace with the number of LEDs in your strip
#define FADE_DELAY 1   // Delay between brightness changes (in milliseconds)
#define MAX_BRIGHTNESS 255 // Maximum brightness value
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  // Increase brightness
  for (int brightness = 0; brightness <= MAX_BRIGHTNESS; brightness++) {
    setBrightness(brightness);
    delay(FADE_DELAY);
  }
  // Decrease brightness
  for (int brightness = MAX_BRIGHTNESS; brightness >= 0; brightness--) {
    setBrightness(brightness);
    delay(FADE_DELAY);
  }
}
void setBrightness(int brightness) {
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB(brightness, brightness, brightness);
  }
  FastLED.show();  // Update the LED strip
}

⇢ Code Example 4: Moving Gradient

Advanced Arduino WS2811 interfacing programming with smooth colour gradients.

#include <FastLED.h>
#define LED_PIN 5        // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50       // Replace with the number of LEDs in your strip
#define GRADIENT_DELAY 50 // Delay between gradient color changes (in milliseconds)
#define MOVEMENT_DELAY 20 // Delay between LED movements (in milliseconds)
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  // Set the initial color gradient
  CRGB startColor = CRGB::Red;
  CRGB endColor = CRGB::Blue;
  // Calculate color step values
  int colorStepsR = (endColor.r - startColor.r) / NUM_LEDS;
  int colorStepsG = (endColor.g - startColor.g) / NUM_LEDS;
  int colorStepsB = (endColor.b - startColor.b) / NUM_LEDS;
  // Move the gradient effect across the LED strip
  for (int i = 0; i < NUM_LEDS; i++) {
    CRGB gradientColor = CRGB(startColor.r + (colorStepsR * i),
                             startColor.g + (colorStepsG * i),
                             startColor.b + (colorStepsB * i));
    // Shift the gradient by moving the LEDs
    for (int j = 0; j < NUM_LEDS; j++) {
      int index = (i + j) % NUM_LEDS;
      leds[index] = gradientColor;
    }
    FastLED.show();  // Update the LED strip
    delay(MOVEMENT_DELAY);  // Delay between LED movements
  }
  // Shift the colors for the next frame
  startColor = endColor;
  endColor = CRGB::Green;
} 

⇢ Code Example 5: Fire Simulation

Realistic fire effect using advanced WS2811 Arduino code, FastLED techniques.

#include <FastLED.h>
#define LED_PIN 5         // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50       // Replace with the number of LEDs in your strip
#define FLICKER_DELAY 20  // Delay between flicker changes (in milliseconds)
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  // Set the initial color for the candle flame
  CRGB flameColor = CRGB::Red;
  // Create a flickering effect
  for (int i = 0; i < NUM_LEDS; i++) {
    // Randomly flicker the LEDs
    if (random(10) < 5) {
      leds[i] = flameColor;
    } else {
      leds[i] = CRGB::Black;
    }
  }
  FastLED.show();  // Update the LED strip
  delay(FLICKER_DELAY);  // Delay between flicker changes
}

 

Troubleshooting WS2811 Arduino Projects

Problem	Possible Cause	Solution
LEDs not lighting up	Power supply insufficient	Use an external 5V power supply
Colours are wrong	Wrong colour order in code	Try RGB, GRB, or BGR in FastLED.addLeds()
Only the first LED works	Data line issue	Check wiring, add 470Ω resistor
Random flickering	Power supply noise	Add capacitors, check ground connections

Technical Summary And GitHub Repository 

The Technical Summary and GitHub Repository provide detailed insights and resources for WS8211 RGB LED Strip with Arduino, showcasing innovative applications and control techniques. 

 

Frequently Asked Questions WS2811 LED Strip

⇥ 1. What is the primary distinction between WS2811 and WS2812 LED strip systems? 
WS2811 has the driver in an external chip from the light itself.  WS2812 has an internal driver on the discrete LED itself.  Both can be interfaced and run on Arduino with the same interface and wiring, and also the FastLED library.

⇥ 2. How many WS2811 LEDs can I use on an Arduino at the same time?  
In theory, an Arduino Uno should run 1000+ WS2811 LEDs.  In practice, however, you realistically have to limit it to approximately 300-500 LEDs for memory and refresh rate purposes, so the animation stays acceptable.

⇥ 3. Can I run the WS2811 LED strip from the 5V pin on the Arduino?
Yes, for fewer than about 10 LEDs, the LED strip can be powered from the 5V pin of the Arduino. Beyond that length, always power the LED strip from an external 5V supply source. Also, note that the voltage regulator on the Arduino will only support a maximum current of 500mA, and this is mostly not enough for any long LED strip.

⇥ 4. Which Arduino pin is recommended for the WS2811 data channel?
Technically, it can be any digital pin to drive the data channel; however, the recommended and common pins are 5, 6, or 7. It is important to avoid pins 0-1 (Serial) (these pins are used for USB communication), pin 13 (onboard LED) and any pins that are already wired somewhere else in your sensor gadget.

⇥ 5. Why Do My LEDs Display Incorrect Colours Or Flash?
Possible causes could be a dud power supply, the colour order in the program set incorrectly (GRB and not RGB), loose connections, or maybe an absence of common ground between the power supply and the Arduino.

⇥ 6. Are WS2811 LED Strips cuttable and extendable?
Yes, but only trim down in the marked positions (generally every 3 LEDs). During wiring back, keep polarity: +5V (red), GND (black), DATA (green/white).

⇥ 7. What is the maximum distance between the Arduino and the WS2811 strip?
Keep the data line at < 3 meters for normal functioning. For longer cable runs, use level shifters (5V to 3.3V) or use a 120ω termination resistor at the strip end.

Explore Innovative LED-Based Projects

In our past work, LEDs have been featured in various creative projects; you can find the details in the links below.

Code for Pattern 1:
#include <FastLED.h>
#define LED_PIN 5    // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50  // Replace with the number of LEDs in your strip
#define DELAY_TIME 20  // Delay between LED movements (in milliseconds)
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  // Turn off all LEDs
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB::Black;
  }
  // Move the LED chaser
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB::Blue;  // Set the current LED to blue
    FastLED.show();  // Update the LED strip
    delay(DELAY_TIME);  // Delay between LED movements
  }
  // Move the LED chaser in reverse
  for (int i = NUM_LEDS - 1; i >= 0; i--) {
    leds[i] = CRGB::Green;  // Set the current LED to green
    FastLED.show();  // Update the LED strip
    delay(DELAY_TIME);  // Delay between LED movements
  }
}
 
Code for Pattern 2:
#include <FastLED.h>
#define LED_PIN 5    // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50  // Replace with the number of LEDs in your strip
#define DELAY_TIME 50  // Delay between color changes (in milliseconds)
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  static uint8_t hue = 0;  // Hue value for color shifting
  // Set all LEDs to the current hue
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CHSV(hue, 255, 255);
  }
  FastLED.show();  // Update the LED strip
  delay(DELAY_TIME);  // Delay between color changes
  // Shift the hue for the next frame
  hue++;
}
 
Code for Pattern 3:
#include <FastLED.h>
#define LED_PIN 5       // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50      // Replace with the number of LEDs in your strip
#define FADE_DELAY 1   // Delay between brightness changes (in milliseconds)
#define MAX_BRIGHTNESS 255 // Maximum brightness value
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  // Increase brightness
  for (int brightness = 0; brightness <= MAX_BRIGHTNESS; brightness++) {
    setBrightness(brightness);
    delay(FADE_DELAY);
  }
  // Decrease brightness
  for (int brightness = MAX_BRIGHTNESS; brightness >= 0; brightness--) {
    setBrightness(brightness);
    delay(FADE_DELAY);
  }
}
void setBrightness(int brightness) {
  for (int i = 0; i < NUM_LEDS; i++) {
    leds[i] = CRGB(brightness, brightness, brightness);
  }
  FastLED.show();  // Update the LED strip
}
 
Code for Pattern 4:
#include <FastLED.h>
#define LED_PIN 5         // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50       // Replace with the number of LEDs in your strip
#define GRADIENT_DELAY 50 // Delay between gradient color changes (in milliseconds)
#define MOVEMENT_DELAY 20 // Delay between LED movements (in milliseconds)
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  // Set the initial color gradient
  CRGB startColor = CRGB::Red;
  CRGB endColor = CRGB::Blue;
  // Calculate color step values
  int colorStepsR = (endColor.r - startColor.r) / NUM_LEDS;
  int colorStepsG = (endColor.g - startColor.g) / NUM_LEDS;
  int colorStepsB = (endColor.b - startColor.b) / NUM_LEDS;
  // Move the gradient effect across the LED strip
  for (int i = 0; i < NUM_LEDS; i++) {
    CRGB gradientColor = CRGB(startColor.r + (colorStepsR * i),
                             startColor.g + (colorStepsG * i),
                             startColor.b + (colorStepsB * i));
    // Shift the gradient by moving the LEDs
    for (int j = 0; j < NUM_LEDS; j++) {
      int index = (i + j) % NUM_LEDS;
      leds[index] = gradientColor;
    }
    FastLED.show();  // Update the LED strip
    delay(MOVEMENT_DELAY);  // Delay between LED movements
  }
  // Shift the colors for the next frame
  startColor = endColor;
  endColor = CRGB::Green;
}
 
Code for Pattern 5:
#include <FastLED.h>
#define LED_PIN 5         // Replace with the pin number you used for DATA connection
#define NUM_LEDS 50       // Replace with the number of LEDs in your strip
#define FLICKER_DELAY 20  // Delay between flicker changes (in milliseconds)
CRGB leds[NUM_LEDS];
void setup() {
  FastLED.addLeds<WS2811, LED_PIN, RGB>(leds, NUM_LEDS);
}
void loop() {
  // Set the initial color for the candle flame
  CRGB flameColor = CRGB::Red;
  // Create a flickering effect
  for (int i = 0; i < NUM_LEDS; i++) {
    // Randomly flicker the LEDs
    if (random(10) < 5) {
      leds[i] = flameColor;
    } else {
      leds[i] = CRGB::Black;
    }
  }
  FastLED.show();  // Update the LED strip
  delay(FLICKER_DELAY);  // Delay between flicker changes
}