/*SwitchManager skeleton
LarryD
Switch with debounce switch case and Limit Counter
This sketch is to introduce new people to the SwitchManager library written by
Nick Gammon
The library handles switch de-bouncing and provides timing and state
change information in your sketch.
The SwitchManager.h file should be placed in your libraries folder, i.e.
C:\Users\YourName\Documents\Arduino\libraries\SwitchManager\SwitchManager.h
You can download the library at:
http://gammon.com.au/Arduino/SwitchManager.zip Thank you Nick!
In this example we have 2 normally open (N.O.) switches connected to the Arduino
- increment and decrement.
The increment switch will also be used as a "Reset" switch if pressed for more than
two seconds.
The two switches are connected between GND (0 volts) and an Arduino input pin.
The library enables pull-up resistors for your switch inputs.
Pushing a switch makes its pin LOW. Releasing a switch makes its pin HIGH.
The SwitchManager library provides 10ms de-bounce for switches.
i.e. enum { debounceTime = 10, noSwitch = -1 };
If you need more time, edit the SwitchManager.h file
i.e. enum { debounceTime = 50, noSwitch = -1 }; //here it is changed to 50ms
*/
#include <LiquidCrystal_I2C.h>
LiquidCrystal_I2C lcd(0x27, 20, 4);
#include <SwitchManager.h>
//object instantiations
SwitchManager myIncSwitch;
SwitchManager myDecSwitch;
unsigned long currentMillis;
unsigned long heartBeatMillis;
unsigned long heartFlashRate = 500UL; // time the led will change state
unsigned long incShortPress = 500UL; // 1/2 second
unsigned long incLongPress = 2000UL;// 2 seconds
unsigned long decShortPress = 500UL; // 1/2 second
const byte heartBeatLED = 13;
const byte incSwitch = 4; //increment switch is on Arduino pin 4
const byte decSwitch = 5; //decrement switch is on Arduino pin 5
int myCounter;
//======================================================================
void setup()
{
Serial.begin(9600);
lcd.init();
lcd.backlight();
lcd.setCursor(1, 0);
lcd.print("Hello, Wokwi!");
//gives a visual indication if the sketch is blocking
pinMode(heartBeatLED, OUTPUT);
myIncSwitch.begin (incSwitch, handleSwitchPresses);
myDecSwitch.begin (decSwitch, handleSwitchPresses);
//the handleSwitchPresses() function is called when a switch changes state
} // E N D o f s e t u p ( )
//======================================================================
void loop()
{
//leave this line of code at the top of loop()
currentMillis = millis();
//***************************
//some code to see if the sketch is blocking
if (CheckTime(heartBeatMillis, heartFlashRate, true))
{
//toggle the heartBeatLED
digitalWrite(heartBeatLED,!digitalRead(heartBeatLED));
}
//***************************
//check to see what's happening with the switches
//"Do not use delay()s" in your sketch as it will make switch changes unresponsive
//Use BlinkWithoutDelay (BWD) techniques instead.
myIncSwitch.check ();
myDecSwitch.check ();
//*********************************
//put other non-blocking stuff here
//*********************************
} // E N D o f l o o p ( )
//======================================================================
// F U N C T I O N S
//======================================================================
// C h e c k T i m e ( )
//**********************************************************************
//Delay time expired function
//parameters:
//lastMillis = time we started
//wait = delay in ms
//restart = do we start timing again
boolean CheckTime(unsigned long & lastMillis, unsigned long wait, boolean restart)
{
//has time expired for this task?
if (currentMillis - lastMillis >= wait)
{
//should this start again?
if(restart)
{
//yes, get ready for the next iteration
lastMillis += wait;
}
return true; //the timer has timed out
}
return false; //the timer has not timed out
} // E N D o f C h e c k T i m e ( )
// h a n d l e S w i t c h P r e s s e s( )
//**********************************************************************
void handleSwitchPresses(const byte newState, const unsigned long interval, const byte whichPin)
{
//You get here 'ONLY' if there has been a change in a switches state.
//when a switch has changed state, SwitchManager passes this function 3 arguments:
//"newState" this will be HIGH or LOW. This is the state the switch is in now.
//"interval" the number of milliseconds the switch stayed in the previous state
//"whichPin" is the switch pin that we are examining
switch (whichPin)
{
//********************************
//are we dealing with this switch?
case incSwitch:
//has this switch gone from LOW to HIGH (gone from pressed to not pressed)
//this happens with normally open switches wired as mentioned at the top of this sketch
if (newState == HIGH)
{
//The incSwitch was just released
//was this a short press followed by a switch release
if(interval <= incShortPress)
{
Serial.print("My counter value is = ");
myCounter++;
if(myCounter > 1000)
{
//limit the counter to a maximum of 1000
myCounter = 1000;
}
Serial.println(myCounter);
}
//was this a long press followed by a switch release
else if(interval >= incLongPress)
//we could also have an upper limit
//if incLongMillis was 2000UL; we could then have a window between 2-3 seconds
//else if(interval >= incLongMillis && interval <= incLongMillis + 1000UL)
{
//This could be used to change states in a StateMachine
//We could increment the mycounter by 10 etc.
//in this example however, we will just RESET myCounter
myCounter = 0;
Serial.print("My counter value is now RESET = ");
Serial.println(myCounter);
}
}
//if the switch is a normally closed (N.C.) and opens on a press this section would be used
//the switch must have gone from HIGH to LOW
else
{
Serial.println("The incSwitch was just pushed");
}
break; //End of case incSwitch
//********************************
//are we dealing with this switch?
case decSwitch:
//has this switch gone from LOW to HIGH (gone from pressed to not pressed)
//this happens with normally open switches wired as mentioned at the top of this sketch
if (newState == HIGH)
{
//The decSwitch was just released
//was this a short press followed by a switch release
if(interval <= decShortPress)
{
Serial.print("My counter value is = ");
myCounter--;
if(myCounter < 0)
{
//don't go below zero
myCounter = 0;
}
Serial.println(myCounter);
}
}
//if the switch is a normally closed (N.C.) and opens on a press this section would be used
//the switch must have gone from HIGH to LOW
else
{
Serial.println("The decSwitch switch was just pushed");
}
break; //End of case decSwitch
//***************************
//Put default stuff here
//default:
//break; //END of default
} //End of switch (whichPin)
} // E n d o f h a n d l e S w i t c h P r e s s e s ( )
//======================================================================
// E N D O F C O D E
//======================================================================