boolean pushButton1;
boolean pushButton2;
int ledpin=9;
int brightness=128;
void setup() {
  // put your setup code here, to run once:
  pinMode(2,INPUT_PULLUP);
  pinMode(8,INPUT_PULLUP);
  pinMode(ledpin,OUTPUT);
  Serial.begin(9600);
}

void loop() {
  // put your main code here, to run repeatedly:
  pushButton1=digitalRead(2);//变暗按键
  pushButton2=digitalRead(8);//变亮按键
  if(!pushButton1 && brightness > 0)
  {
    brightness--;
  }
  if(!pushButton2 && brightness < 255)
  {
    brightness++;
  }
  analogWrite(ledpin,brightness);
  Serial.println(brightness);
  delay(10);
  
}