Chrono

Chronometer/stopwatch library that counts the time passed since started.

Get It!

• Download the source
• Chrono on Github

Adding Chrono

Copy the Chrono folder to your Arduino or Wiring libraries folder or download it with the Arduino library manager.

Basic Example

// INCLUDE CHRONO LIBRARY
// Documentation : https://github.com/SofaPirate/Chrono-Arduino-Wiring/blob/master/README.md
// Download : https://github.com/SofaPirate/Chrono-Arduino-Wiring/archive/master.zip
#include  <Chrono.h>

// Instanciate a Chrono object.
Chrono myChrono; 

void setup() {

}

void loop() {
  // Check whether the chronometer has reached 1000 time units.
  if (myChrono.hasPassed(1000)) {
    myChrono.restart(); // Restart the chronometer.

    // Do something here...
  }
}

Basic Usage

Include the library

// INCLUDE CHRONO LIBRARY : http://github.com/SofaPirate/Chrono
#include <Chrono.h>

Create an instance

Once a Chrono is created, it starts counting (in milliseconds by default).

// CREATE A CHRONO INSTANCE :
Chrono myChrono;

Basic Methods

elapsed()	unsigned long	Returns the elapsed time
restart()	void	Sets the elapsed time to 0 and starts the chronometer
hasPassed( timeout )	bool	Returns true if the chronometer passed the timeout

Example: Blinking the debug LED

/*
 This code will toggle pin 13 on and off every second (1000 ms).
 This should be the debug LED's pin. So the debug LED should
 blink every second.
 */

// INCLUDE CHRONO LIBRARY : http://github.com/SofaPirate/Chrono
#include  

// Set the led's pin
int ledPin =  13; 

//Create a variable to hold the led's state
int ledState = HIGH;

// Instanciate a Chrono object.
Chrono ledChrono; 

void setup()
{
  pinMode(ledPin,OUTPUT);
  digitalWrite(ledPin,ledState);
}

void loop()
{

  if (ledChrono.hasPassed(1000) ) { // returns true if it passed 1000 ms since it was started
    ledChrono.restart();  // restart the crono so that it triggers again later
    
    // toggle the stored state
    if (ledState==HIGH)  ledState=LOW;
    else ledState=HIGH;
    
    // write the state to the pin
    digitalWrite(ledPin,ledState);
  }
}

Example: Blinking 2 LEDS

// This code will toggle output 13 every 250 ms
// and will toggle output 9 every 125 ms


// INCLUDE CHRONO LIBRARY : http://github.com/SofaPirate/Chrono
#include  

// Create variables for the LED pins
int ledPinA =  13;
int ledPinB =  9;

// Create variables to hold the LED states
int ledStateA = HIGH;
int ledStateB = HIGH;

// Instantiate two Chronos
Chrono chronoA; 
Chrono chronoB; 

void setup()
{
  pinMode(ledPinA,OUTPUT);
  digitalWrite(ledPinA,ledStateA);
  
   pinMode(ledPinB,OUTPUT);
  digitalWrite(ledPinB,ledStateB);
  
}

void loop()
{
  // Use Chrono as a metronome with an interval of 250 ms: 
  if ( chronoA.hasPassed(250) ) { // returns true if it passed 250 ms since it was started
    chronoA.restart(); // restart the crono so that it triggers again later
    ledStateA = !ledStateA; // !: toggle the state from 0 to 1 or from 1 to 0
    digitalWrite(ledPinA,ledStateA);
  }
  
  // Use Chrono as a metronome with an interval of 125 ms: 
   if ( chronoB.hasPassed(125) ) { // returns true if it passed 125 ms since it was started
    chronoB.restart(); // restart the crono so that it triggers again later
    ledStateB = !ledStateB; // !: toggle the state from 0 to 1 or from 1 to 0
    digitalWrite(ledPinB,ledStateB);
  }
  
  
}

Advanced Usage

Time units

You can create a Chrono that counts in microseconds or seconds:

Chrono myChronoMicros(Chrono::MICROS);

Chrono myChronoSeconds(Chrono::SECONDS);

Custom time function

Alternatively you can create a Chrono with a custom time function:

unsigned long mySpecialTimeFunction();

Chrono myChronoMicros(mySpecialTimeFunction);

Advanced Methods

restart( offset )	void	You can alternatively start(restart) the chronometer with a time offset
stop()	void	Stops/pauses the chronometer
resume( )	void	Resumes the chronometer
hasPassed( timeout,restartIfPassed )	bool	If the chronometer passed the timeout, returns true and restarts the chronometer
add( time )	void	Immediately adds some time to the chronometer
isRunning( )	bool	Returns true if the chronometer is currently running
delay( time )	void	Waits for some time (in the time unit of the chronometer)