Arduino Basics: Control Structures

Control structures are programming constructs that allow you to control the flow of your Arduino sketch. They help your program make decisions, perform repeated tasks, and respond dynamically to inputs such as sensors or buttons. Without control structures, an Arduino program would simply execute commands sequentially from top to bottom, making it impossible to handle real-world interactions effectively.

Common Control Structures

• if: Executes a block of code only if a specific condition is true. This is useful for checking sensor values, button presses, or any other condition in your program.

  Example:

  if (temperature > 30) {
    turnOnFan();
  }

• else: Works in combination with if and executes a block of code when the if condition is false. This allows your program to handle both outcomes of a condition.

  Example:

  if (buttonPressed) {
    turnOnLED();
  } else {
    turnOffLED();
  }

• for: Repeats a block of code a set number of times. It is often used for counting loops, blinking LEDs multiple times, or iterating through arrays.

  Example:

  for (int i = 0; i < 5; i++) {
    blinkLED();
  }

• while: Repeats a block of code as long as a specified condition remains true. This is useful for waiting until a certain event occurs, such as a button being pressed or a sensor reaching a threshold.

  Example:

  while (sensorValue < threshold) {
    readSensor();
  }

• switch: Allows you to test a variable against multiple possible values and execute code depending on which value matches. This is useful when you have many conditions based on a single variable, like selecting modes or responding to sensor states.

  Example:

  switch (mode) {
    case 1:
      turnOnLED();
      break;
    case 2:
      blinkLED();
      break;
    case 3:
      turnOffLED();
      break;
    default:
      doNothing();
      break;
  }

Example: Using Control Structures Together

Here’s an example that combines if and else to control an LED based on a button press:

if (buttonState == HIGH) {
  turnOnLED();   // LED turns on if the button is pressed
} else {
  turnOffLED();  // LED turns off if the button is not pressed
}

Why Control Structures Are Important

Control structures are essential in Arduino programming because they allow your sketch to:

• Make decisions based on input from sensors, buttons, or user actions.

• Repeat tasks without rewriting the same code multiple times, saving space and improving readability.

• Create dynamic and responsive programs that react to the environment in real time.

• Organize code logically, making it easier to debug and expand your projects.

By mastering control structures, you can move from simple, linear programs to complex interactive projects like robots, home automation systems, and sensor-based applications.