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This tutorial will discuss millis()the use of functions in different applications in Arduino. This tutorial will also discuss some examples to better understand millis()the functions.

millis()Checking the elapsed time in Arduino using the

millis()The function returns unsigned longan unsigned variable of type that contains the number of milliseconds that have passed since the Arduino board started running the code. Since the variable returned is of type unsigned long, the number will overflow and reset to zero after 49 days.

unsigned long currentTime;

void setup() { Serial.begin(19200); }

void loop() {
  Serial.print("Time Stamp: ");
  currentTime = millis();
  Serial.println(currentTime);
  delay(1000);
}

In the above code, currentTimeis unsigned longa variable of type which is used to store the time. Check out this link for millis()more information about the function.

millis()Blinking LED in Arduino using function

In this example, we will millis()blink an LED using the delay() function. Consider that you have to blink the LED for a specific time, say 1 second. In this case, you can use millis()the delay() function to blink the LED for a specific time. If you use the delay() function to blink the LED, it will also pause your code until the delay time is over. So, millis()instead of using the delay() function delay(), you can use the delay() function and it will not pause your code.

unsigned long startTime;
unsigned long currentTime;
const unsigned long period = 1000;
const byte ledPin = 13;

void setup() {
  pinMode(ledPin, OUTPUT);
  startTime = millis();  // initial start time
}

void loop() {
  currentTime = millis();
  if (currentTime - startTime >= period)  // test whether the period has elapsed
  {
    digitalWrite(ledPin,
                 !digitalRead(ledPin));  // if so, change the state of the LED.
    startTime = currentTime;
  }
}

In this example, the LED will turn on and off for exactly one second. You can change the blinking period by changing the value of the variable period in the code above.

millis()Change the brightness of an LED in Arduino using the

In this example, we will millis()change the brightness of an LED using the function. We will set a period during which the brightness of the LED will increase. To do this, we need to connect the LED with a PWM pin of the Arduino. We can write the brightness to the LED using the analogWrite() function. We can analogWritechange the brightness of the LED between 0 and 255 using the function.

unsigned long startTime;
unsigned long currentTime;
const unsigned long period = 10;
const byte ledPin = 10;  // using an LED on a PWM pin.
byte LedBrightness = 0;  // initial brightness
byte LedIncrement = 1;   // amount to change the brightness

void setup() {
  pinMode(ledPin, OUTPUT);
  startTime = millis();  // initial start time
}

void loop() {
  currentTime = millis();
  if (currentTime - startTime >= period) {
    analogWrite(ledPin, LedBrightness);  // set the brightness
    LedBrightness += LedIncrement;
    startTime = currentTime;
  }
}

In this example, the LED brightness will increase every 10 milliseconds. You can change the increment time by changing the variable period in the code above.