LIVE MINI ESP32开发板教程系列(四)NeoPixel + ws2812b实现炫彩显示
- 实验材料
- WS2812b简介
- LIVE MINI ESP32开发板引脚图
- 硬件连接
- 测试时连线图
- 独立使用时的连线图
- 库安装
- 方式一:直接用`管理库`进行安装
- 方式二:安装`ZIP`包
- 源代码
- 单纯彩虹效果显示源代码
- 带按键可进行显示效果切换的源代码
- 原理图
- 源代码
- 实物图
实验材料
LIVE MINI ESP32 *1
WS2812b灯带 (其实不限款式~)
四脚按键 *1 (可选)
杜邦线若干
5V电源(本文用的是一个充电宝拆的~,因为笔者的灯带是5v的,如果你的是12V款,换成12V电源即可)
WS2812b简介
WS2812B是一款常用的RGB灯珠。市面上占有率很高。一米30灯珠的灯带某宝可能也就7、8元左右。其内部是自带芯片的。驱动器来比以前单纯的led灯珠要方便很多。
LIVE MINI ESP32开发板引脚图
硬件连接
- WS2812b灯带是有方向的,以8位的灯带为例,可以发现灯带两端都是有外接的导线的。但是仔细观察会发现标注略有不同,一侧为GND、VCC、
DIN
、GND,而另一侧为GND、VCC、DOUT
、GND。其中DIN
和DOUT
标识了灯带的使用方向。多条灯带串联使用的时候务必注意连接的方向。每一级的out
都要和in
端相连。 - 调试和独立使用的时候供电会有所不同,所以硬件连接稍有区别。请根据自己的实际情况选择相应的硬件连接方式。
测试时连线图
测试时一般都需要将ESP32芯片通过安卓线接到电脑的USB口,此时芯片可以通过安卓供电。
独立使用时的连线图
独立使用的时候注意要把5V的电源接入ESP32芯片的VCC
端
库安装
方式一:直接用管理库
进行安装
- 在菜单栏选择
项目
->加载库
->管理库
。 - 在搜索栏键入
neopixel
回车后稍等即可见到Adafruit NeoPixel
,点击install
进行安装。
方式二:安装ZIP
包
有的时候方式一的安装会受到网络状态影响,进而导致安装失败。所以可以下载ZIP
包。这样安装成功率高些,但是比方法一稍微复杂丢丢。
- 在菜单栏选择
项目
->加载库
->添加.ZIP库...
。
源代码
该源代码是在Neopixel的buttoncycler示例的基础上进行更改的。分为两个测试例程:第一个为没有按键的单纯彩虹色显示效果测试;第二个为通过按键进行显示效果的切换。
单纯彩虹效果显示源代码
// Simple demonstration on using an input device to trigger changes on your
// NeoPixels. Wire a momentary push button to connect from ground to a
// digital IO pin. When the button is pressed it will change to a new pixel
// animation. Initial state has all pixels off -- press the button once to
// start the first animation. As written, the button does not interrupt an
// animation in-progress, it works only when idle.
#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
#include <avr/power.h> // Required for 16 MHz Adafruit Trinket
#endif
// Digital IO pin connected to the button. This will be driven with a
// pull-up resistor so the switch pulls the pin to ground momentarily.
// On a high -> low transition the button press logic will execute.
//#define BUTTON_PIN 2 //这个简单彩虹显示的例子里没有用到按键所以注释掉
#define PIXEL_PIN 16 // 连接灯带Din的引脚时LIVE MINI ESP32的GPIO16
#define PIXEL_COUNT 8 // 测试时使用的是8颗灯珠的ws2812b灯带盘。你可以根
//据你手头的灯带上的灯珠数量进行修改:比如16颗就
//改成16。32颗就改成32
// Declare our NeoPixel strip object:
Adafruit_NeoPixel strip(PIXEL_COUNT, PIXEL_PIN, NEO_GRB + NEO_KHZ800);
// Argument 1 = Number of pixels in NeoPixel strip
// Argument 2 = Arduino pin number (most are valid)
// Argument 3 = Pixel type flags, add together as needed:
// NEO_KHZ800 800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
// NEO_KHZ400 400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
// NEO_GRB Pixels are wired for GRB bitstream (most NeoPixel products)
// NEO_RGB Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
// NEO_RGBW Pixels are wired for RGBW bitstream (NeoPixel RGBW products)
void setup() {
pinMode(BUTTON_PIN, INPUT_PULLUP);
strip.begin(); // Initialize NeoPixel strip object (REQUIRED)
strip.show(); // Initialize all pixels to 'off'
rainbow(10);//彩虹显示效果
// theaterChaseRainbow(10);//可以切换成其他效果
}
void loop() {
}
// Fill strip pixels one after another with a color. Strip is NOT cleared
// first; anything there will be covered pixel by pixel. Pass in color
// (as a single 'packed' 32-bit value, which you can get by calling
// strip.Color(red, green, blue) as shown in the loop() function above),
// and a delay time (in milliseconds) between pixels.
void colorWipe(uint32_t color, int wait) {
for(int i=0; i<strip.numPixels(); i++) { // For each pixel in strip...
strip.setPixelColor(i, color); // Set pixel's color (in RAM)
strip.show(); // Update strip to match
delay(wait); // Pause for a moment
}
}
// Theater-marquee-style chasing lights. Pass in a color (32-bit value,
// a la strip.Color(r,g,b) as mentioned above), and a delay time (in ms)
// between frames.
void theaterChase(uint32_t color, int wait) {
for(int a=0; a<10; a++) { // Repeat 10 times...
for(int b=0; b<3; b++) { // 'b' counts from 0 to 2...
strip.clear(); // Set all pixels in RAM to 0 (off)
// 'c' counts up from 'b' to end of strip in steps of 3...
for(int c=b; c<strip.numPixels(); c += 3) {
strip.setPixelColor(c, color); // Set pixel 'c' to value 'color'
}
strip.show(); // Update strip with new contents
delay(wait); // Pause for a moment
}
}
}
// Rainbow cycle along whole strip. Pass delay time (in ms) between frames.
void rainbow(int wait) {
// Hue of first pixel runs 3 complete loops through the color wheel.
// Color wheel has a range of 65536 but it's OK if we roll over, so
// just count from 0 to 3*65536. Adding 256 to firstPixelHue each time
// means we'll make 3*65536/256 = 768 passes through this outer loop:
for(long firstPixelHue = 0; firstPixelHue < 3*65536; firstPixelHue += 256) {
for(int i=0; i<strip.numPixels(); i++) { // For each pixel in strip...
// Offset pixel hue by an amount to make one full revolution of the
// color wheel (range of 65536) along the length of the strip
// (strip.numPixels() steps):
int pixelHue = firstPixelHue + (i * 65536L / strip.numPixels());
// strip.ColorHSV() can take 1 or 3 arguments: a hue (0 to 65535) or
// optionally add saturation and value (brightness) (each 0 to 255).
// Here we're using just the single-argument hue variant. The result
// is passed through strip.gamma32() to provide 'truer' colors
// before assigning to each pixel:
strip.setPixelColor(i, strip.gamma32(strip.ColorHSV(pixelHue)));
}
strip.show(); // Update strip with new contents
delay(wait); // Pause for a moment
}
}
// Rainbow-enhanced theater marquee. Pass delay time (in ms) between frames.
void theaterChaseRainbow(int wait) {
int firstPixelHue = 0; // First pixel starts at red (hue 0)
for(int a=0; a<30; a++) { // Repeat 30 times...
for(int b=0; b<3; b++) { // 'b' counts from 0 to 2...
strip.clear(); // Set all pixels in RAM to 0 (off)
// 'c' counts up from 'b' to end of strip in increments of 3...
for(int c=b; c<strip.numPixels(); c += 3) {
// hue of pixel 'c' is offset by an amount to make one full
// revolution of the color wheel (range 65536) along the length
// of the strip (strip.numPixels() steps):
int hue = firstPixelHue + c * 65536L / strip.numPixels();
uint32_t color = strip.gamma32(strip.ColorHSV(hue)); // hue -> RGB
strip.setPixelColor(c, color); // Set pixel 'c' to value 'color'
}
strip.show(); // Update strip with new contents
delay(wait); // Pause for a moment
firstPixelHue += 65536 / 90; // One cycle of color wheel over 90 frames
}
}
}
带按键可进行显示效果切换的源代码
这个源代码添加了一个按键。按键一端接在GPIO17,一端接地。
原理图
源代码
// Simple demonstration on using an input device to trigger changes on your
// NeoPixels. Wire a momentary push button to connect from ground to a
// digital IO pin. When the button is pressed it will change to a new pixel
// animation. Initial state has all pixels off -- press the button once to
// start the first animation. As written, the button does not interrupt an
// animation in-progress, it works only when idle.
#include <Adafruit_NeoPixel.h>
#ifdef __AVR__
#include <avr/power.h> // Required for 16 MHz Adafruit Trinket
#endif
// Digital IO pin connected to the button. This will be driven with a
// pull-up resistor so the switch pulls the pin to ground momentarily.
// On a high -> low transition the button press logic will execute.
#define BUTTON_PIN 17//按键接在17引脚
#define PIXEL_PIN 16 //16引脚接ws2816b的DIN
#define PIXEL_COUNT 8 // 灯珠的数量
// Declare our NeoPixel strip object:
Adafruit_NeoPixel strip(PIXEL_COUNT, PIXEL_PIN, NEO_GRB + NEO_KHZ800);
// Argument 1 = Number of pixels in NeoPixel strip
// Argument 2 = Arduino pin number (most are valid)
// Argument 3 = Pixel type flags, add together as needed:
// NEO_KHZ800 800 KHz bitstream (most NeoPixel products w/WS2812 LEDs)
// NEO_KHZ400 400 KHz (classic 'v1' (not v2) FLORA pixels, WS2811 drivers)
// NEO_GRB Pixels are wired for GRB bitstream (most NeoPixel products)
// NEO_RGB Pixels are wired for RGB bitstream (v1 FLORA pixels, not v2)
// NEO_RGBW Pixels are wired for RGBW bitstream (NeoPixel RGBW products)
boolean oldState = HIGH;
int mode = 0; // Currently-active animation mode, 0-9
void setup() {
pinMode(BUTTON_PIN, INPUT_PULLUP);
strip.begin(); // Initialize NeoPixel strip object (REQUIRED)
strip.show(); // Initialize all pixels to 'off'
}
void loop() {
// Get current button state.
boolean newState = digitalRead(BUTTON_PIN);
// Check if state changed from high to low (button press).
if((newState == LOW) && (oldState == HIGH)) {
// Short delay to debounce button.
delay(20);
// Check if button is still low after debounce.
newState = digitalRead(BUTTON_PIN);
if(newState == LOW) { // Yes, still low
if(++mode > 8) mode = 0; // Advance to next mode, wrap around after #8
switch(mode) { // Start the new animation...
case 0:
colorWipe(strip.Color( 0, 0, 0), 50); // Black/off
break;
case 1:
colorWipe(strip.Color(255, 0, 0), 50); // Red
break;
case 2:
colorWipe(strip.Color( 0, 255, 0), 50); // Green
break;
case 3:
colorWipe(strip.Color( 0, 0, 255), 50); // Blue
break;
case 4:
theaterChase(strip.Color(127, 127, 127), 50); // White
break;
case 5:
theaterChase(strip.Color(127, 0, 0), 50); // Red
break;
case 6:
theaterChase(strip.Color( 0, 0, 127), 50); // Blue
break;
case 7:
rainbow(10);
break;
case 8:
theaterChaseRainbow(50);
break;
}
}
}
// Set the last-read button state to the old state.
oldState = newState;
}
// Fill strip pixels one after another with a color. Strip is NOT cleared
// first; anything there will be covered pixel by pixel. Pass in color
// (as a single 'packed' 32-bit value, which you can get by calling
// strip.Color(red, green, blue) as shown in the loop() function above),
// and a delay time (in milliseconds) between pixels.
void colorWipe(uint32_t color, int wait) {
for(int i=0; i<strip.numPixels(); i++) { // For each pixel in strip...
strip.setPixelColor(i, color); // Set pixel's color (in RAM)
strip.show(); // Update strip to match
delay(wait); // Pause for a moment
}
}
// Theater-marquee-style chasing lights. Pass in a color (32-bit value,
// a la strip.Color(r,g,b) as mentioned above), and a delay time (in ms)
// between frames.
void theaterChase(uint32_t color, int wait) {
for(int a=0; a<10; a++) { // Repeat 10 times...
for(int b=0; b<3; b++) { // 'b' counts from 0 to 2...
strip.clear(); // Set all pixels in RAM to 0 (off)
// 'c' counts up from 'b' to end of strip in steps of 3...
for(int c=b; c<strip.numPixels(); c += 3) {
strip.setPixelColor(c, color); // Set pixel 'c' to value 'color'
}
strip.show(); // Update strip with new contents
delay(wait); // Pause for a moment
}
}
}
// Rainbow cycle along whole strip. Pass delay time (in ms) between frames.
void rainbow(int wait) {
// Hue of first pixel runs 3 complete loops through the color wheel.
// Color wheel has a range of 65536 but it's OK if we roll over, so
// just count from 0 to 3*65536. Adding 256 to firstPixelHue each time
// means we'll make 3*65536/256 = 768 passes through this outer loop:
for(long firstPixelHue = 0; firstPixelHue < 3*65536; firstPixelHue += 256) {
for(int i=0; i<strip.numPixels(); i++) { // For each pixel in strip...
// Offset pixel hue by an amount to make one full revolution of the
// color wheel (range of 65536) along the length of the strip
// (strip.numPixels() steps):
int pixelHue = firstPixelHue + (i * 65536L / strip.numPixels());
// strip.ColorHSV() can take 1 or 3 arguments: a hue (0 to 65535) or
// optionally add saturation and value (brightness) (each 0 to 255).
// Here we're using just the single-argument hue variant. The result
// is passed through strip.gamma32() to provide 'truer' colors
// before assigning to each pixel:
strip.setPixelColor(i, strip.gamma32(strip.ColorHSV(pixelHue)));
}
strip.show(); // Update strip with new contents
delay(wait); // Pause for a moment
}
}
// Rainbow-enhanced theater marquee. Pass delay time (in ms) between frames.
void theaterChaseRainbow(int wait) {
int firstPixelHue = 0; // First pixel starts at red (hue 0)
for(int a=0; a<30; a++) { // Repeat 30 times...
for(int b=0; b<3; b++) { // 'b' counts from 0 to 2...
strip.clear(); // Set all pixels in RAM to 0 (off)
// 'c' counts up from 'b' to end of strip in increments of 3...
for(int c=b; c<strip.numPixels(); c += 3) {
// hue of pixel 'c' is offset by an amount to make one full
// revolution of the color wheel (range 65536) along the length
// of the strip (strip.numPixels() steps):
int hue = firstPixelHue + c * 65536L / strip.numPixels();
uint32_t color = strip.gamma32(strip.ColorHSV(hue)); // hue -> RGB
strip.setPixelColor(c, color); // Set pixel 'c' to value 'color'
}
strip.show(); // Update strip with new contents
delay(wait); // Pause for a moment
firstPixelHue += 65536 / 90; // One cycle of color wheel over 90 frames
}
}
}
实物图
我因为想接下来做个小机器音箱,所以选了两个8灯珠的圆环WS2812B并联在一起了。