uno用两个按键分别控制led灯亮度增加和减少

以下是Uno的代码：

int ledPin = 9; //定义LED引脚

int brightness = 0; //初始亮度为0

int buttonUp = 2; //定义增加亮度按钮

int buttonDown = 3; //定义减少亮度按钮

void setup() {

pinMode(ledPin, OUTPUT);

pinMode(buttonUp, INPUT_PULLUP);

pinMode(buttonDown, INPUT_PULLUP);

}

void loop() {

//检测增加亮度按钮是否按下

if (digitalRead(buttonUp) == LOW) {

brightness++;

if (brightness > 255) {

brightness = 255;

}

}

//检测减少亮度按钮是否按下

if (digitalRead(buttonDown) == LOW) {

brightness--;

if (brightness < 0) {

brightness = 0;

}

}

analogWrite(ledPin, brightness); //设置LED亮度

delay(10);

}