ESP32 Tutorial 12/55 - WS2812 RGB Srip 4 Project with SunFounder's ESP32 IoT Learning kit

本课是……的一部分: 基于 SunFounder ESP32 IoT 学习套件的 ESP32 Arduino 课程（55 个教程/视频）

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ESP32 Tutorial 12/55 - WS2812 RGB Srip 4 Project with SunFounder's ESP32 IoT Learning kit

In this tutorial, we will explore how to control a WS2812 LED strip using the ESP32 microcontroller. This project allows you to create a variety of colors and control each LED individually, providing a fun and visually appealing way to learn about programming and electronics. By the end of this tutorial, you will have a fully functional setup that can change colors and patterns dynamically.

SunFounder-ESP32-Lesson-12-LED-Strip.mp4_snapshot_00.02.422

Using the ESP32 microcontroller from SunFounder, which features built-in Wi-Fi and Bluetooth capabilities, we can easily connect and control the WS2812 RGB LED strip. The flexibility of this LED strip allows for creative applications, whether for decorative lighting or educational projects. For a better understanding of the steps involved, you can refer to the video at (in video at 00:00).

Hardware Explained

The main components for this project include the ESP32 microcontroller and the WS2812 LED strip. The ESP32 is a powerful microcontroller that can perform tasks similar to those of an Arduino, but with added connectivity options. It has a rich set of features that enable it to connect to the cloud, allowing for remote control and data logging.

The WS2812 LED strip consists of individually addressable RGB LEDs, which means that each LED can be controlled to display different colors. The strip operates on a single-wire protocol, allowing multiple LEDs to be chained together without losing signal quality. Each LED contains a built-in driver that takes the input signal and amplifies it for the next LED in the chain.

Datasheet Details

Manufacturer	Worldsemi
Part number	WS2812
Logic/IO voltage	3.5–5.3 V
Supply voltage	5 V
Output current (per channel)	20 mA max
Peak current (per channel)	60 mA max
PWM frequency guidance	400 Hz
Input logic thresholds	0.3 x V_DD to 0.7 x V_DD
Voltage drop / R_DS(on) / saturation	0.5 V max
Thermal limits	-25 to 80 °C
Package	5050
Notes / variants	Can be chained for longer strips

Ensure proper power supply (5 V) to avoid LED damage.
Use a capacitor (100 µF) across the power supply terminals to smooth voltage spikes.
Keep data wires short to reduce signal degradation.
Be cautious of the LED temperature; ensure proper heat dissipation.
Observe correct polarity when connecting power and ground.
Utilize a pull-up resistor on the data line if using long strips.

Wiring Instructions

To wire the WS2812 LED strip to the ESP32, start by connecting the power supply. The +5V wire from the LED strip should be connected to the 5V pin on the ESP32, and the ground (GND) wire should be connected to one of the GND pins on the ESP32.

Next, connect the data input wire from the LED strip to pin 14 on the ESP32. Make sure the connections are secure to ensure proper data transmission. If you are using multiple strips or longer distances, consider using a level shifter to ensure signal integrity. This setup will allow you to control the LED strip directly from the ESP32.

Code Examples & Walkthrough

The code uses the Adafruit NeoPixel library to control the WS2812 LED strip. It starts by initializing the LED strip and setting the initial color to black. The key identifiers in the code include LED_PIN, which defines the pin connected to the data line of the LED strip, and NUM_LEDS, which specifies the number of LEDs in the strip.

#include  // Include the Adafruit NeoPixel library

#define LED_PIN 14 // NeoPixel LED strip
#define NUM_LEDS 8 // Number of LEDs

In the setup function, the strip is initialized using strip.begin(), and the initial color is set to black with strip.show(). This prepares the strip for color changes when the program runs.

void setup() {
  strip.begin(); // Initialize the NeoPixel strip
  strip.show(); // Set initial color to black
}

The main loop of the program consists of two for loops. The first loop turns on each LED one by one by setting its color and updating the strip. The second loop turns off each LED in the same manner. This creates a simple but effective light animation.

void loop() {
  // Turn on LEDs one by one
  for (int i = 0; i < NUM_LEDS; i++) {
    strip.setPixelColor(i, 100, 45, 0); // Set the color of the i-th LED to red
    strip.show(); // Update the LED strip with the new colors
    delay(100); // Wait for 100 milliseconds
  }
  
  // Turn off LEDs one by one
  for (int i = 0; i < NUM_LEDS; i++) {
    strip.setPixelColor(i, 0, 0, 0); // Set the color of the i-th LED to black (turn it off)
    strip.show(); // Update the LED strip with the new colors
    delay(100); // Wait for 100 milliseconds
  }
}

Watch the complete code loading below the article for more details on how to implement different color effects and animations.

Demonstration / What to Expect

Once you have completed the wiring and uploaded the code, you should see the LEDs on the strip light up one by one in a specified color, followed by them turning off in the same sequence. This creates a "running light" effect. If the LEDs do not light up as expected, double-check your wiring connections and ensure the power supply is adequate. Also, verify that the correct pin is defined in the code (in video at 12:30).