LCD 1602 I2C背光无按键输入自动关闭

 

#include <Bounce2.h>

Bounce btn =Bounce(2,50);//宣告按键

int LCDbacklight=LOW; //存储LCD背光状态

long previousMillis = 0;

long interval = 15000;   

void setup() {
pinMode(2,INPUT);


}

void loop()

 {
   unsigned long currentMillis = millis(); //系统运行时间

 if(LCDbacklight==HIGH);
   {
    if(currentMillis - previousMillis > interval)
    {

     lcd.noBacklight();  //LCD背光关闭
     LCDbacklight=LOW;
   }
   }

  if(btn.update()==true && btn.read()==HIGH)
  {
previousMillis = currentMillis;
  LCDbacklight=HIGH; //存储LCD背光状态

  lcd.backlight();//打开LCD背光

}