ARDUINO TIMER INTERRUPT

 

In this tutorial we are going to enable Arduino timer Interrupt

COMPONENTS REQUIREMENT

LED

LCD

ARDUINO UNO

CODE

#include<LiquidCrystal.h>   //LCD display library

#define ledPin 7

LiquidCrystal lcd(8,9,10,11,12,13);

int count=0;

float value = 49910;  //Preload timer value (3035 for 4 seconds)

 

// 65535-((16*10^6)*(time sec))/1024;

// sec 1 / 2 / 3

void setup()

{

  lcd.begin(16,2);

  lcd.setCursor(0,0);

  lcd.print("ARDUINO TIMERS");

  delay(2000);

  lcd.clear();

 

  pinMode(ledPin, OUTPUT);

  pinMode(2,INPUT);

  pinMode(4,INPUT);

 

  noInterrupts();           // disable all interrupts

 

  TCCR1A = 0;

  TCCR1B = 0;

  TCNT1 = value;              // preload timer

  TCCR1B |= (1 << CS10)|(1 << CS12);    // 1024 prescaler

  TIMSK1 |= (1 << TOIE1);   // enable timer overflow interrupt ISR

  interrupts();             // enable all interrupts

}

 ISR(TIMER1_OVF_vect) // interrupt service routine for overflow

{

  TCNT1 = value; // preload timer

  if(count==250)

  {

  digitalWrite(ledPin, digitalRead(ledPin) ^ 1); 

//Turns LED ON and OFF

  count=0;

  }

  count++;

}

 void loop()

{

 

}