led

1、 LED示例一：开关LED 示例功能：使用选择3个LED模块中的一个，例程用来驱动LED亮灭1秒钟，循环交替 硬件接线：使用3P连接线，连接在扩展板上的3号PH2.0防呆口上。

const int ledPin = 3;  // 控制LED的GPIO引脚

void setup() {
  pinMode(ledPin, OUTPUT);  // 设置引脚为输出模式
}

void loop() {
  digitalWrite(ledPin, HIGH);  // 点亮LED
  delay(1000);                 // 保持1秒
  digitalWrite(ledPin, LOW);   // 熄灭LED
  delay(1000);                 // 保持1秒
}

2、 LED示例二：呼吸灯 示例功能：以下程序将使用GPIO9号口连接LED模块，使用ESP32的LEDC PWM功能实现渐变效果。 硬件接线：使用3P连接线，连接在扩展板上的9号PH2.0防呆口上。

int led = 9;         // the PWM pin the LED is attached to
int brightness = 0;  // how bright the LED is
int fadeAmount = 5;  // how many points to fade the LED by

// the setup routine runs once when you press reset:
void setup() {
  // declare pin 9 to be an output:
  pinMode(led, OUTPUT);
}

// the loop routine runs over and over again forever:
void loop() {
  // set the brightness of pin 9:
  analogWrite(led, brightness);

  // change the brightness for next time through the loop:
  brightness = brightness + fadeAmount;

  // reverse the direction of the fading at the ends of the fade:
  if (brightness <= 0 || brightness >= 255) {
    fadeAmount = -fadeAmount;
  }
  // wait for 30 milliseconds to see the dimming effect
  delay(30);
}

Arduino IDE内置示例

/*
  Blink
*/
// the setup function runs once when you press reset or power the board
const int ledPins[] = {3, 6, 7, 8, 9, 10, 13, 15, 16, 17, 35,36,37,45};
const int numLeds = sizeof(ledPins) / sizeof(ledPins[0]);

void setup() 
{
  //初始化所有LED引脚为输出模式
  for (int i = 0; i < numLeds; i++) 
  {
    pinMode(ledPins[i], OUTPUT);
    digitalWrite(ledPins[i], LOW); // 确保所有LED初始状态为关闭
  }
}

void loop() 
{
  //依次点亮每个LED
  for (int i = 0; i < numLeds; i++) 
  {
    digitalWrite(ledPins[i], HIGH); // 点亮LED
    delay(10); // 延迟200毫秒
    digitalWrite(ledPins[i], LOW); // 关闭LED
  }
}