What are interrupts in Arduino and how do I use them?

What are interrupts in Arduino and how do I use them?

Interrupts in Arduino are signals that temporarily halt the main program to execute a specific function. They are useful for handling events like button presses or sensor readings without constantly checking their state.

Can you give me an example of how to implement an interrupt?

Sure! Here's a simple example: You can use the attachInterrupt() function to call a function when a button is pressed. For instance:

volatile int buttonState = 0;

void setup() {
  pinMode(2, INPUT);
  attachInterrupt(digitalPinToInterrupt(2), handleButtonPress, RISING);
}

void loop() {
  // Main code here
}

void handleButtonPress() {
  buttonState = 1;
}

What does the 'volatile' keyword do in this context?

The 'volatile' keyword tells the compiler that the variable can be changed unexpectedly, such as by an interrupt. This prevents the compiler from optimizing the code in a way that could lead to incorrect behavior.

Are there any limitations to using interrupts?

Yes, there are limitations. For example, you should keep the interrupt service routine (ISR) short and avoid using functions like delay() or Serial.print() inside it, as they can cause delays and affect performance.