const byte btn1 = 2 ;
const byte btn2 = 3 ;

void setup() {
pinMode(btn1, INPUT);
pinMode(btn2, INPUT);

}

void loop() {
int btn1State = digitalRead(btn1);
int btn2State = digitalRead(btn2);
delay (100) ;

Serial.begin(9600);
Serial.print ("btn1 : ") ;
Serial.print (btn1State) ;
Serial.print (" ") ;
Serial.print ("btn2 : ") ;
Serial.print (btn2State) ;

}