108个传感器之-三色LED（15）

介绍

该LED模块包含通过公共阴极连接的红色，蓝色和绿色LED。红色LED的正向电压为1.8 V，而绿色和蓝色LED则需要2.8V。所有LED的正向电流为20 mA。使用此模块，您可以通过调整单个LED的亮度来创建不同的颜色。它是需要视觉信号或彩色显示器的应用。通用阴极使连接并集成到各种项目中，无论是用于装饰照明，状态显示还是其他创意应用程序。

Technical Data
Forward voltage [Red]	1.8 V
Forward voltage [Green, Blue]	2.8 V
Forward current	20 mA

引脚连接

pin 引脚连接开发板的 gpio 接口即可：

Arduino	Sensor
Pin 2	LED Red
Pin 3	LED Green
Pin 4	LED Blue
GND	GND

代码示例

1. 普通版

int led_red = A2; // Pin for red
int led_green = A3; // Pin for green
int led_blue = A4; // Pin for blue
  
void setup() {
  pinMode(led_red, OUTPUT); 
  pinMode(led_green, OUTPUT);
  pinMode(led_blue, OUTPUT); 
}

void loop () {
  digitalWrite(led_red, HIGH); // red LED is switched on
  digitalWrite(led_green, LOW); // green LED is switched off
  digitalWrite(led_blue, LOW); // blue LED is switched off
  delay(3000); 
  
  digitalWrite(led_red, LOW); // red LED is switched off
  digitalWrite(led_green, HIGH); // green LED is switched on
  digitalWrite(led_blue, LOW); // blue LED is switched off
  delay(3000);
   
  digitalWrite(led_red, LOW); // red LED is switched off
  digitalWrite(led_green, LOW); // green LED is switched off
  digitalWrite(led_blue, HIGH); // blue LED is switched on
  delay(3000); 
}

2. 渐变版

#include <Arduino.h>

// led pin 定义
const int redPin = A2;
const int greenPin = A3;
const int bluePin = A4;
const int freq = 5000; // PWM 信号频率（单位 Hz）
const int redChannel = 0; // PWM 通道
const int greenChannel = 1; // PWM 通道
const int blueChannel = 2; // PWM 通道
const int resolution = 8; // PWM 分辨率，8位代表 0-255 的范围

void setup()
{
  Serial.begin(9600);
  ledcSetup(redChannel, freq, resolution);
  ledcAttachPin(redPin, redChannel);
  ledcSetup(greenChannel, freq, resolution);
  ledcAttachPin(greenPin, greenChannel);
  ledcSetup(blueChannel, freq, resolution);
  ledcAttachPin(bluePin, blueChannel);
}

void loop()
{
  // 让 PWM 渐变从 0 到 255（亮度从暗到亮）
  for (int dutyCycle = 0; dutyCycle <= 255; dutyCycle++) {
    ledcWrite(redChannel, dutyCycle); // 设置 PWM 占空比
    ledcWrite(greenChannel, 255 - dutyCycle); // 设置 PWM 占空比
    ledcWrite(blueChannel, 128 - dutyCycle); // 设置 PWM 占空比
    delay(10); // 延迟 10 毫秒，实现渐变效果
  }

  // 让 PWM 渐变从 255 到 0（亮度从亮到暗）
  for (int dutyCycle = 255; dutyCycle >= 0; dutyCycle--) {
    ledcWrite(redChannel, dutyCycle); // 设置 PWM 占空比
    ledcWrite(greenChannel, 255 - dutyCycle); // 设置 PWM 占空比
    ledcWrite(blueChannel, 128 - dutyCycle); // 设置 PWM 占空比
    delay(10); // 延迟 10 毫秒，实现渐变效果
  }

小结

三色LED模块通过调整单个LED的亮度来创建不同的颜色，非常适合需要视觉信号或彩色显示器的应用。