Arduino-Time Function

This article details the use of the Arduino Time function.

The Time function can be used to pause the program for the amount of time or to measure the time since running the program.

For other Arduino functions and libraries, please refer to the following article.

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Time Functions

delay()/Pauses the program for the amount of time(ms)

The delay() function pauses the program for the amount of time by setting a wait time (ms: 1/1000 second) as an parameter.

delayMicroseconds()/Pauses the program for the amount of time(us)

The delayMicroseconds() function pauses the program for the amount of time by setting a wait time (us: 1/1000000 second) as an parameter.

millis()/Returns the number of milliseconds(ms) since running the program

The millis() function measures and returns the time (ms: 1/1000 second) since running the program.

micros()/Returns the number of microseconds(us) since running the program

The micros() function measures and returns the time (ms: 1/1000000 second) since running the program.

Sample Programs (Sample Sketches)

delay()/Pauses the program for the amount of time(ms)

void setup() {
  pinMode(13, OUTPUT);//Set pin 13 as OUTPUT
}

void loop() {
  digitalWrite(13, HIGH);//Pin 13 output set to HIGH (5V)
  delay(1000);//Wait 1000msec (1sec)
  digitalWrite(13, LOW);//Pin 13 output set to LOW (0V)
  delay(1000);//Wait 1000msec (1sec)
}

The sample program waits for the LED on the Arduino Uno board to turn on and off every 1000ms, blinking at 1-second intervals.

delayMicroseconds()/Pauses the program for the amount of time(us)

void setup() {
  pinMode(13, OUTPUT);//Set pin 13 as OUTPUT
}

void loop() {
  digitalWrite(13, HIGH);//Pin 13 output set to HIGH (5V)
  delayMicroseconds(25000);//Wait 25000usec (0.025sec)
  delayMicroseconds(25000);//Wait 25000usec (0.025sec)
  delayMicroseconds(25000);//Wait 25000usec (0.025sec)
  delayMicroseconds(25000);//Wait 25000usec (0.025sec), Total 0.1 sec wait
  digitalWrite(13, LOW);//Pin 13 output set to LOW (0V)
  delayMicroseconds(25000);//Wait 25000usec (0.025sec)
  delayMicroseconds(25000);//Wait 25000usec (0.025sec)
  delayMicroseconds(25000);//Wait 25000usec (0.025sec)
  delayMicroseconds(25000);//Wait 25000usec (0.025sec), Total 0.1 sec wait
}

The sample program waits for the LED on the Arduino Uno board to turn on and off every 100000us, blinking at 0.1-second intervals.

millis()/Returns the number of milliseconds(ms) since running the program

void setup() {
  Serial.begin(9600);//Initialize serial communication at 9600bps
}

void loop() {
  unsigned long time;//Declare "time" as a variable with unsigned long
  delay(1000);//Wait 1000msec (1sec)
  time = millis();//Return time (ms) since running the program
  Serial.print(time);//Send time (ms)
  Serial.println("ms");//Send string "ms", New line
}

The sample program repeatedly waits for the program for 1 second, then measures the elapsed time and displays it on the serial monitor.

The numbers displayed on the serial monitor do not add up to exactly every 1000ms because other program execution times are added in addition to delay(1000).

micros()/Returns the number of microseconds(us) since running the program

void setup() {
  Serial.begin(9600);//Initialize serial communication at 9600bps
}

void loop() {
  unsigned long time;//Declare "time" as a variable with unsigned long
  delay(1000);//Wait 1000msec (1sec)
  time = micros();//Return time (us) since running the program
  Serial.print(time);//Send time (us)
  Serial.println("us");//Send string "us", New line
}

The sample program repeatedly waits for the program for 1 second, then measures the elapsed time and displays it on the serial monitor.

The numbers displayed on the serial monitor do not add up to exactly every 1000000us because other program execution times are added in addition to delay(1000).