TimedEvents

An Arduino/non-arduino-AVR library to keep track of when events occured, like when an input changed, when an output/variable was written...etc. The point of this library is that the time is counted with millis and not delay/_delay_ms, so several events can be timed easily without blocking each other.

How it works

The library is divided into 3 entities :

The IoItem :

• is an encapsulation of variable, a pin or port (for non-arduino)
• it offers an interface for functions to read/write/toggle/change IO direction/get current value (last read/written value)
• it stores information of the real target in case of pin/port, and the current value (in memory)

The Controller :

• is used to store the last time IoItem was changed either by read or write
• has functions to read/write/toggle the IoItem
• has functions to check for changes and how long ago the change was done
• implements a software debounce (when an input changes, its value is not updated during the debounce time)

The Timer :

• a sort of Controller but doesn't depend on IoItem
• it has functions to Start, to Reset and to detect if time is reached
• the time span is initialized with the constructor
• the point of it is to measure time for other events that can't be caught by the Controller (ex : commands from Serial, value read by a sensor)

How to use :

• Create an instance of the IoItem you want to control
• Create an instance of a controller for that IoItem
• use the controller to read/write/toggle
• you can also use the class Timer if you wan't to measure time for different events

#include <TimedEvents.h>

// IoItems
ControlledArduinoPin led(LED_BUILTIN,OUTPUT);
ControlledArduinoPin btn(2,INPUT_PULLUP);

// Controllers
PinController ledController(led); // PinController is ValueController<uint8_t>
PinController btnController(btn); // 

// Timer
Timer tmr(1000);

void setup()
{
   Serial.begin(9600);
   delay(5); // to avoid millis returning 0 (not necessary anymore)
   btnController.Debounce = 50; // set debounce
}

void loop()
{
   if (ledController.TimeReached(500)) // toggles LED every 500ms
       ledController.Toggle();
       
   btnController.Read(); // should read periodically to detect change and save when happened
   
   if (btnController.Changed()) // detects all variations
                                // in order to detect for example rising edge only include btnController.Read in the condition 
                                // or check btn.Value()
   {
       Serial.print("Value state ");
       Serial.println(btn.Value() ? "ON" : "OFF");
   }

   if (Serial.available())
   {
       Serial.read();
       tmr.Start(true); // start timer with force restart, so it starts counting when the last characeter of the message is received
   }

   if (tmr.Reached()) // checking a timer will either reset it or restart it, so in order to use this information further it should be saved
       Serial.println("1 second since message received");
} 

Notes:

• In order to check for an input change it must be read periodically
• Any read/write/toggle done directly to IoItem are ignored by the controller, so whether it changed and when it changed are both not updated
• The non-arduino version needs to include an implementation of millis and initialize it (a modified copy from the Arduino repo is provided)
• Since the library detects that a changed occured by having its timestamp no null, it's advised to use a delay at the beginning of the program to avoid millis returning 0