Time

delayMicroseconds()

Pauses the program for the amount of time (in microseconds) specified as parameter. There are a thousand microseconds in a millisecond, and a million microseconds in a second.

// SYNTAX
delayMicroseconds(us);

us is the number of microseconds to pause (unsigned int)

// EXAMPLE USAGE

int outPin = D1;              // digital pin D1

void setup()
{
  pinMode(outPin, OUTPUT);    // sets the digital pin as output
}

void loop()
{
  digitalWrite(outPin, HIGH); // sets the pin on
  delayMicroseconds(50);      // pauses for 50 microseconds
  digitalWrite(outPin, LOW);  // sets the pin off
  delayMicroseconds(50);      // pauses for 50 microseconds
}

Since 1.5.0:

You can also specify a value using chrono literals, for example: delayMicroseconds(2ms) for 2 milliseconds, but you should generally avoid using long delay values with delayMicroseconds.