Timer

Arduino timer library. Perfect for removing delay() functions from your code and to create asynchronous tasks easily.

It supports callbacks with functions and methods, so you can use it inside your classes

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Installation

1. Download the latest release from github
2. Unzip and rename the folder to "Timer" (remove the -master)
3. Paste the modified folder on your Library folder (.../Arduino/libraries)
4. Reopen the Arduino IDE

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Usage

Let's see the basic usage

#include "timer.h"

// Create the timer instance
Timer timer;

void helloCallback() {
  Serial.println("Hello");
}

void setup()
{
  Serial.begin(9600);
  
  // The timer will repeat every 1000 ms
  timer.setInterval(1000); 

  // The function to be called
  timer.setCallback(helloCallback);

  // Start the timer
  timer.start();
}

void loop()
{
  //Update the timer
  timer.update();
}

Using the same code above, you can change it to call the helloCallback a limited number of times

  // The timer will repeat every 1000 ms and will call the callback only 5 times
  timer.setInterval(1000, 5);

If you want to call only once, there is a method for that

  // Will call the callback only once
  timer.setTimeout(1000);

Now imagine I have a class. How would I use the Timer if it works only with functions?

Easy, wrap the method inside a function

  void callMyMethod() {
    instance.myMethod();
  }
  
  timer.setCallback(callMyMethod);

Or, you can use the TimerForMethods class

  MyClass myInstance;
  TimerForMethods<MyClass> timer(&myInstance, &MyClass::myMethod);

Altough it's more verbose, it's very useful if a timer is beeing used inside a class.

What if I have a lot of timers? Do I have to keep calling start, update, stop, ..., for every single timer?

Of course not! I'm here to help. Look at this magic

#include "timer.h"
#include "timerManager.h"

Timer timer1;
Timer timer2;
Timer timer3;
Timer timer4;
Timer timer5;

... // Write your callbacks

void setup() {
  ... // Write your setup logic
  
  //Start all the timers
  TimerManager::instance().start();
}

void loop() {
  ... // Write your loop logic
  
  //Update all the timers at once
  TimerManager::instance().update();

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Library Reference

Timer class

• Timer() - Constructor

• ~Timer() - Destructor

• void start() - Starts the timer

• void stop() - Stops and resets the timer

• void pause() - Pauses the timer. It can continue where it paused after calling start method

• void reset() - Resets the timer elapsed time. If the timer is running, it will continue to do so

• unsigned long getElapsedTime() - Returns the elapsed time in milliseconds

• void setInterval(unsigned long interval, int repeat_count=-1) - Sets the interval time. The callback function will be called every "interval" ms. The repeat count will prevent the callback from being called after a number of repetetions (if it's > 0). WARNING: The timer will stop after that (if repeat count > 0)

• void setTimeout(unsigned long timeout) - Sets the timeout time. The callback function will be called just once. WARNING: The timer will stop after that

• void clearInterval() - Removes the interval, so the timer can be used as a normal timer

• void setCallback(void (*function)(void)) - Sets the callback function

• void update() - Updates the timer. It must be called in a loop in order to make it work

• bool isPaused() - Check if the timer is paused

• bool isStopped() - Check if the timer is stopped

• bool isRunning() - Check if the timer is running

• protected virtual void call() - Calls the callback function

• private unsigned long initial_time - Stores the start time

• private unsigned long current_time - Stores the current time

• private bool is_running - Stores if the timer is running

• private bool is_paused - Stores if the timer is paused

• private unsigned long interval - Stores the interval, if setted

• private unsigned long last_interval_time - Stores the last time the callback was called

• private int repeat_count - Stores the number of times remaining to call the callback function

• private int total_repeat_count - Stores the number of times to call the callback function

• private bool interval_is_setted - Stores if the interval was setted

• private void (*function_callback)(void) - Stores the callback function

TimerForMethods class

• TimerForMethods(Obj *object, void (Obj::*callback)(void)) - Constructor

• virtual void call() - Calls the callback method

• private Obj *object - Stores the object to be used

• private void (Obj::*method)(void) - Stores the method to be called

TimerManager class

• static TimerManager& instance() - Get the TimerManager instance
• void update() - Updates all timers
• void start() - Starts all timers
• void stop() - Stops and resets all timers
• void pause() - Pauses all timers
• void reset() - Resets elapsed time of all timers. If any timer was running, it will continue to do so
• private void add(Timer *timer) - Adds a timer to the TimerManager
• private bool remove(Timer *timer) - Removes a timer from the TimerManager. Return true if the timer was removed, false otherwise
• private TimerManager() - Constructor
• private TimerManager(TimerManager const &) - Constructor
• private void operator=(TimerManager const &) - Copy operator
• private class TimerNode - A node of Timers used to implement a simple linked list
• private TimerNode *first - A pointer to the first TimerNode
• private TimerNode *last - A pointer to the last TimerNode

TimerManager::TimerNode class

• TimerNode *next - A pointer to the next TimerNode
• Timer *value - A pointer to the Timer instance associated with this node

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License

MIT