How can I make the code stop when a specific button is pressed?

[StefanL38]

function delay() does what its name says

delaying (everything) until the delay() has finished.
This means as long as the delay() is "active" no other line of code can be executed.

For your wanted functionality of stop the pump with a button you use a "software"-switch
almost the same way as you would use an elctromechanical switch.
switch "ON" machine/pump/lamp "active"
switch "OFF" machine/pump/lamp "INactive"

inside code such a software-"switch" is coded by an if-condition

the basic principle looks like this

boolean pumpActive;

void loop() {
  if (pumpActive == true) {
    // execute code that makes the pump run
  }

  if (digitalRead(myStopButton_Pin == pressed) {
    pumpActive = false
  }
  

The button must be checked all the time = many times per second
This means you can't use delay

The same applies if you want to use an IR-remote
You must check all the time = many times per second if a new remote-command was sended

You have to use non-blocking timing which is as one example explained here

Example-code for timing based on millis() easier to understand through the use of example-numbers / avoiding delay()

non-blocking timing. Execute code only from time to time. There are a lot of different ways to learn programming. This thread wants to add another approach that is different to the yet existing ones. UPDATE 06.01.2023 if you are mainly interested in applying non-blocking timing you can do a quick read of this short tutorial / demonstration If you are intersted in understanding the details how it works go on reading here. I use an everyday analogon in this post to explain the basic principle …

I'm very interested in beginners questions to improve my tutorials.
So feel free to ask as much as you want.

To have a minmal number of if-conditions you can use a programming-tecnique called state-machine.
Which is explained here

A Demo-Code explaining the switch-case state-machine and how to do things (almost) in parallel

Hi everybody, if you look at the end of this first posting you see a list of links that show where this tutorial was used as a link. Go through this list to find additional information on how to apply this code This democode requires only the pure microcontroller without any hardware. You just open the serial monitor to watch the behaviour of the code. From time to time I enjoy writing demo-codes that want to explain programming-functionalities. There are a lot of different approachs to expl…

best regards Stefan