資料型態轉換的問題 - Robofun 機器人論壇

#include <Wire.h>
#include <LiquidCrystal_I2C.h>
int pushButton = 7;
int ledpin = 8;
int x = 0;
int t;

LiquidCrystal_I2C lcd(0x27, 16, 2);

void setup()
{
      pinMode(pushButton, INPUT);
      pinMode(ledpin, OUTPUT);


      lcd.begin();
      lcd.backlight();
      lcd.setCursor(0,0);

char s[] = {'b1','b2'};
int t = atoi(s);

}

void loop()
{
  char a1,a2,b1,b2;
  b1='8';
  b2='1';
  lcd.setCursor(1,1);
  lcd.write(b1);
  lcd.setCursor(0,1);
  lcd.write(b2);
  int i;
  i = digitalRead(pushButton);
  if(i == HIGH)
  {
x++;
a1=x%10;
a2=(x/10)%10;
lcd.setCursor(1,0);
lcd.write(a1+'0');
lcd.setCursor(0,0);
lcd.write(a2+'0');

if (x>=20) x=0;
  }
if( x >= t)
{
digitalWrite(ledpin, HIGH);
}
else
{
digitalWrite(ledpin, LOW);
}
}