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.

Currently, the largest value that will produce an accurate delay is 16383. This could change in future Arduino releases. For delays longer than a few thousand microseconds, you should use delay() instead.

delayMicroseconds(us)

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

None

int outPin = 8;                 // digital pin 8
 
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      
}

configures pin number 8 to work as an output pin. It sends a train of pulses with 100 microseconds period.

This function works very accurately in the range 3 microseconds and up. We cannot assure that delayMicroseconds will perform precisely for smaller delay-times.

As of Arduino 0018, delayMicroseconds() no longer disables interrupts.

* millis() * micros() * delay()

Source: arduino.cc