I want to build up a system, when a horn touch a switch. The information can be gotten by Arduino card. But I don't know how many pins the switch should have? All I know is the voltage should be 5V, and since the space is quite limited, the size of the switch should be really small. Could you help with this? give all the limitation to the switch, or suggest some kinds of switches.
I am a green hand of control system.
touch not tough. sorry for that
This is something that does not need an Arduino, what is using one going to do for you?
I think it should be needed. Since the Ardunio will control some valves, AC power input, and so on. I need some kind of switches to give the accuracy time of some movements.
Your switch needs a minimum of two pins. Usually one is wired to the Arduino ground and the other is wired to the desired input pin. Then use the INPUT_PULLUP option of pinMode() to set the internal pull-up resistor in the Arduino.
digitalRead(MyPinNumber) == LOW will tell you that the switch is currently being pressed.