Removing delay command when using time with arduino (ds1307)

Projects Programming
1

I'm trying to use a ds1307 module to use time with my project. The following is my code to make an LED light up for 5 seconds when I press a push button. Problem is I have to hold the button for a second because of the "delay(1000)" line. Eventually I plan on showing the time on an LCD screen so if I remove the delay I wont be able to display the time. How do I make it so that the button can just be pressed and let go, without holding it down?

#include <Time.h>  
#include <Wire.h>  
#include <DS1307RTC.h>  // a basic DS1307 library that returns time as a time_t

const int button = 2;
const int led = 8;

int buttonState = 0;
time_t timeStart;
time_t timeEnd;

void setup()  {
  Serial.begin(9600);
  
  pinMode(button, INPUT);
  pinMode(led, OUTPUT);
  
  while (!Serial) ; // wait until Arduino Serial Monitor opens
  setSyncProvider(RTC.get);   // the function to get the time from the RTC
  if(timeStatus()!= timeSet) 
     Serial.println("Unable to sync with the RTC");
  else
     Serial.println("RTC has set the system time");
}

void loop(){
  
  buttonState = digitalRead(button);
  
  timeStart = (hour() * 60 * 60) + (minute() * 60) + second();
  
  if(buttonState == HIGH){
    timeEnd = ((hour() * 60 * 60) + (minute() * 60) + second())+5;
  }
  
  if ((timeEnd-timeStart) >=5){
    digitalWrite(led, LOW);
  } else{
    digitalWrite(led, HIGH);
  }

  delay(1000);
}
2

You would attach the button to an Interrupt Pin which will allow the state of that pin (and hence the buttons state) to react on it being pressed instantly.

See http://arduino.cc/en/Reference/AttachInterrupt#.UyuNufmSyT8

You can only use certain pins for Interrupts
You need to declare an interrupt, usually in setup() and declare the interrupt method which gets run when the interrupt is triggered, in your case you would make your LED light up code an interrupt method.

attachInterrupt(interrupt, ISR, mode)

Example of how you could declare it: attachInterrupt(0, ledPressed, RISING)

(Note: CONNECT YOUR BUTTON TO PIN 2. See previous link to see which interrupt numbers correlate to which pins on each arduino model)

This would be your ISR or Interrupt Service Routine.

void ledPressed(){
if(buttonState == HIGH){
timeEnd = ((hour() * 60 * 60) + (minute() * 60) + second())+5;
}
}

3

Look at the blink without delay example. You should not need to update the LCD except when the time changes, say every second, and in between checking the time and update you can check the button status.

You really do not need interrupts, just get rid of the delay().