int speakerPin = 9;//Control horn pin int button_up=A0 ; int button_down=A1 ; float time_limit=0.5; void setup() { pinMode(speakerPin, OUTPUT); pinMode(button_up, INPUT_PULLUP); pinMode(button_down, INPUT_PULLUP); } void loop() { if(digitalRead(button_up) == HIGH) time_limit = time_limit + 5.0; if(digitalRead(button_down) == HIGH) time_limit = time_limit - 5.5; if(time_limit < 0.5) time_limit = 0.5; if(time_limit > 10000.0) time_limit = 10000.0; digitalWrite(speakerPin, HIGH); delay(time_limit); digitalWrite(speakerPin, LOW); delay(time_limit); }