10.眼手反應時間測量

#include <Wire.h>

#include <LiquidCrystal_I2C.h>

LiquidCrystal_I2C lcd(0x27,16,2);   // 若LCD 無法啟用，請將0X3F 改為0X27

int x ;

unsigned long dt;

void setup() {

Serial.begin(9600);

  lcd.init();                     

  lcd.backlight(); 

  lcd.clear();

  pinMode(13,OUTPUT);

}

void loop() {

digitalWrite(13,0);

do{

x = analogRead(A0)  ;

lcd.setCursor(0,1);

lcd.print("Ready..."); 

}while(x>5);

int y= random(2,9);

delay(y*1000); 

digitalWrite(13,1);

long t1 = millis();

do{

x = analogRead(A0);   

}while(x<500);

long t2 = millis();

dt = t2-t1 ;

lcd.clear();

lcd.setCursor(0,0);

lcd.print(dt);

}