Need help adding a countdown function

Sorry if this post is redundant, I tried posting earlier and haven't heard any replies. When I went to find it online to check I couldn't find it. Anyways, I am looking for some help with my push button relay control program. I am trying to create code that when a button is pressed it will close a relay for 1 hr. I found a program on Viral Science that I can use to start, when I push the button it toggles on the relay and when you push the button again it toggles off the relay. I just want to add the 1 hour delay now. I have a Arduino Uno and a 4 channel relay.

//Viral Science Viral Science - The home of Creativity - YouTube
//Push Button Relay Control
int pbuttonPin = 2;
int relayPin = 10;
int pbuttonPin2 = 3;
int relayPin2 = 11;

int val = 0;
int lightON = 1;
int pushed = 0;

int val2 = 0;
int lightON2 = 1;
int pushed2 = 0;

void setup() {
Serial.begin(9600);
pinMode(pbuttonPin, INPUT_PULLUP);
pinMode(relayPin, OUTPUT);
pinMode(pbuttonPin2, INPUT_PULLUP);
pinMode(relayPin2, OUTPUT);

}

void loop() {
val = digitalRead(pbuttonPin);
val2 = digitalRead(pbuttonPin2);

//Relay 1
if(val == HIGH && lightON == LOW){

pushed = 1-pushed;
delay(100);
}
lightON = val;

if(pushed == HIGH){
Serial.println("Light ON");
digitalWrite(relayPin, LOW);

}else{
Serial.println("Light OFF");
digitalWrite(relayPin, HIGH);

}

//Relay 2

if(val2 == HIGH && lightON2 == LOW){

pushed2 = 1-pushed2;
delay(100);
}

lightON2 = val2;

if(pushed2 == HIGH){
Serial.println("Light ON");
digitalWrite(relayPin2, LOW);

}else{
Serial.println("Light OFF");
digitalWrite(relayPin2, HIGH);

}

delay(100);
}

If You follow the advice given You would use code tags when attaching code. Using autoformat in the IDE and then code tags makes the code much more reafable.

The Arduino world calls for programming. That is what You need to do. What is it You don't understand?

I'm inexperienced so don't know if this is the best way and don't know when you want the 1 hour delay. But I was able to do something similar with what you see below.

If other functions would need to happen during the 1 hour delay I believe millis() is a better option.

Before setup
const unsigned long dt=3600000;

In your void loop wherever you want the 1 hour delay

delay(dt);

My appoligies if I have broken any rules of etiquette in my posting. What I am trying to do is create a program that when a button is pushed it toggles on a relay for 1 hour. If the button is pushed before the 1 hour passes it toggles the relay and resets the 1 hour timer. I have a work van with a 1000 watt inverter that I use to charge my cordless tools. I would like to be able to hit the button to turn on the inverter for 1 hour which would allow the batteries to charge and then shut off the inverter.
Thanks again.

Write an object that saves its start time & wait time, then you can ask it if its expired or not. Or just restart it when you need.

Then when the button is pressed

tell the timer object to start.
Fire up the inverter
Set a bool telling you that your in charging mode.

during loop IF in changing mode and timed.expired shut off inverter and clear charging mode variable.

done.

So the timer can be stopped by either a button press or time expired?

scamilleri:
My appoligies if I have broken any rules of etiquette in my posting.

It's not about manners. Without code tags, some code gets interpreted by HTML as emojies. With code tags the code stays in a box that the reader can pull the lower right corner to resize. It keeps the code from taking over the post page.

Autoformatting your code and using whitespace (some people write brick-code) makes it easier by FAR to read.

If you desire fewer people to give you help, make the job of seeing what you have done into some kind of time-wasting challenge. You get extra credit for trivializing efforts to help you.

What I am trying to do is create a program that when a button is pushed it toggles on a relay for 1 hour. If the button is pushed before the 1 hour passes it toggles the relay and resets the 1 hour timer. I have a work van with a 1000 watt inverter that I use to charge my cordless tools. I would like to be able to hit the button to turn on the inverter for 1 hour which would allow the batteries to charge and then shut off the inverter.
Thanks again.

The Arduino delay() function holds code execution until it is done. You can't read a pin for the entire time. There are several such execution-blocking functions (pulseIn(), readUntil,...) to avoid when you want your sketch to do more than one thing at a time like wait and watch a button.

See how well you understand this code below. Take your time, you need a solid understanding. This code is short and does little just so there's less to understand.

This sketch has no button. Adding a button to this fast code means a short lesson in debouncing, otherwise 1 press can look like 6. Thing is that with this code you can add buttons and literally dozens of things and it still works.

And a clue about that 1 hour: the blinkInterval for this example is 1000 milliseconds, it's just a number in the code.

This may get you started on that path:

/*
  Blink without Delay --- cleaned up a bit, 4/5/2020

  Turns on and off a light emitting diode (LED) connected to a digital pin,
  without using the delay() function. This means that other code can run at the
  same time without being interrupted by the LED code.

  The circuit:
  - Use the onboard LED.
  - Note: Most Arduinos have an on-board LED you can control. On the UNO, MEGA
    and ZERO it is attached to digital pin 13, on MKR1000 on pin 6. LED_BUILTIN
    is set to the correct LED pin independent of which board is used.
    If you want to know what pin the on-board LED is connected to on your
    Arduino model, check the Technical Specs of your board at:
    https://www.arduino.cc/en/Main/Products

  created 2005
  by David A. Mellis
  modified 8 Feb 2010
  by Paul Stoffregen
  modified 11 Nov 2013
  by Scott Fitzgerald
  modified 9 Jan 2017
  by Arturo Guadalupi

  This example code is in the public domain.

  http://www.arduino.cc/en/Tutorial/BlinkWithoutDelay
*/

// this code has been cleaned up more to remove bad examples 4/5/2020

// constants won't change. Used here to set a pin number:
const byte ledPin =  LED_BUILTIN;// the number of the LED pin

// Variables will change:
byte ledState = LOW;             // ledState used to set the LED

// Generally, you should use "unsigned long" for variables that hold time
// The value will quickly become too large for an int to store
unsigned long startBlinkInterval = 0;        // will store last time LED was updated

// constants won't change:
const unsigned long blinkInterval = 1000;     // interval at which to blink (milliseconds)

void setup() {
  // set the digital pin as output:
  pinMode(ledPin, OUTPUT);
}

void loop() {
  // here is where you'd put code that needs to be running all the time.

  // check to see if it's time to blink the LED; that is, if the difference
  // between the current time and last time you blinked the LED is bigger than
  // the interval at which you want to blink the LED.

  if (millis() - startBlinkInterval >= blinkInterval) {
    startBlinkInterval += blinkInterval;

    // if the LED is off turn it on and vice-versa:
    if (ledState == LOW) {
      ledState = HIGH;
    } else {
      ledState = LOW;
    }
    digitalWrite(ledPin, ledState);
  }
}

"So the timer can be stopped by either a button press or time expired?"

Yes it can be stopped by either

When button is pressed set a (boolean) flag. If pressed again, clear flag. Basic push on/push off function.

If flag is set, run timer. When timer runs out clear flag.

Debounce the button so you get only one transition per press.

Study and get an understanding of the first five demos in IDE -> file/examples/digital.

Use Serial.print() liberally so you can see what's happening as the program runs.

Use descriptive variable names.