Arduino Development Cookbook

Code basics – Arduino pins

The most important feature of the Arduino is its control over digital input/output (I/O) pins. On each pin, we can set a voltage value of 5 V, representing logic HIGH, or 0 V, representing logic LOW. Also, we can read whether a value of 5 V or 0 V is applied externally. Here we will learn how.

Getting ready

For this recipe, ensure that you have the Arduino IDE running on a computer.

How to do it…

The following code turns a pin HIGH and LOW repeatedly while reading the external voltage applied to another:

void setup() {
  // Set pin 2 as a digital Output
  pinMode(2, OUTPUT);
  // Set pin 3 as a digital Input
  pinMode(3, INPUT);
}

void loop(){
    // Set pin 2 HIGH
  digitalWrite(2, HIGH);
  // Wait 100 milliseconds
  delay(100); // Set ...