Switches

Types:

• Two-position
• Momentary
• Foot pedal
• Roller switches
• Mercury switch (binary tilt)
• Burgular alarm switches (optical, magnetic, ...)
• Multi-position switches ... need different approach than described here

Interfacing Switches to the Arduino Board:

• Two-position switches must produce voltages between 0 - 5 Volts, about a threshold of approximately 1.5 Volts.
• Thus, only two values are possible and these can be read via digital input pins.

• Read pin value using digitalRead( pin ) function:

  int ledPin = 13; // LED connected to digital pin 13
  int inPin = 7;   // pushbutton connected to digital pin 7
  int val = 0;     // variable to store the read value
  
  void setup()
  {
    pinMode(ledPin, OUTPUT);    // sets the digital pin 13 as output
    pinMode(inPin, INPUT);      // sets the digital pin 7 as input
  }
  
  void loop()
  {
    val = digitalRead(inPin);     // read the input pin
    digitalWrite(ledPin, val);    // sets the LED to the button's value
  }