Digital Input

Digital Sensors

• Digital sensors are (more) straight forward (than Analog)

• No matter what the sensor there are only two states: On and Off

• Signal is always either HIGH (On) or LOW (Off)

• Voltage signal for HIGH will be 5V (more or less) on Arduino Uno. Other Arduinos could use different voltages!

• Voltage signal for LOW will be 0V on most systems

Digital Input – Switch (single throw)

Digital Input – Switch (double throw)

NO = normally open C = common NC = normally closed.

Note : The limit switch provided in EG1311 has a different order for NO, C, and NC. The connections in the picture above need to be adapted accordingly.

Using Digital Input

• Connect digital input to your Arduino using Pins # 0 – 13 (Avoid pins # 0 & 1 though as they are used for Serial later, and pin #11 and 13 as we are already using it)

• Digital Input needs a pinMode function

pinMode (pinNumber, INPUT);

Make sure to use ALL CAPS for INPUT

• To get a digital reading:

int buttonState = digitalRead (pinNumber);

• Digital Input values are only HIGH (On) or LOW (Off)

http://opensourcehardwarejunkies.com/tutorial-03-digitalread-and-serial-port-communication/

void setup()
{
  pinMode (pinNumber, INPUT);
}
 
void loop()
{
  int buttonState = digitalRead(2);
 
  if(buttonState == HIGH)
  {  // do something
 
  }
 
  else
  {  // do something else
 
  }
 
}