int t = 0 ;
int BUP = 2 ;
int BDN = 3 ;

void setup() { 
  pinMode(BUP, INPUT); 
  pinMode(BDN, INPUT); 
}

void loop() {
if (digitalRead(BUP)==HIGH){t += 1; if (t > 3) { t = 3;} delay(1000);Serial.println(t);}
if (digitalRead(BDN)==HIGH){t -= 1; if (t < 0) { t = 0;} delay(1000);Serial.println(t);}

}