Asynchronous Timer Interrupt Example

This repository contains an Arduino sketch that demonstrates asynchronous programming using a timer interrupt. The code toggles the built-in LED every 1 second using the TimerOne library, while the main loop prints the current LED state to the Serial Monitor. This example showcases how an interrupt service routine (ISR) can decouple time-sensitive tasks from the main program flow, allowing the system to handle asynchronous events efficiently.

Overview

• Asynchronous Behavior:
  The sketch uses a timer interrupt to toggle the LED independently of the main loop. This means the LED toggle operation occurs even while the main loop is busy, illustrating a core concept of asynchronous programming.

• Timer Interrupt:
  The TimerOne library is employed to generate an interrupt every 1 second. The ISR (toggleLED()) is attached to this interrupt and updates the LED state.

• Serial Output:
  The main loop prints the LED state (ON/OFF) every second to the Serial Monitor, providing real-time feedback.

Prerequisites

• Hardware:
  An Arduino board (e.g., Arduino Uno) with a built-in LED (usually connected to the pin defined as LED_BUILTIN).

• Software:

  • Arduino IDE
  • NRF52_MBED_TimerInterrupt (Install via the Arduino Library Manager)

Installation

1. Clone the Repository:

   git clone https://github.com/yourusername/async-timer-interrupt-example.git
   cd async-timer-interrupt-example

2. Open the Sketch:

   Open the AsyncTimerInterruptExample.ino file in the Arduino IDE.

3. Install the TimerOne Library:

   In the Arduino IDE, navigate to Sketch > Include Library > Manage Libraries.... Search for "NRF52_MBED_TimerInterrupt" and install it if you haven't already.

4. Upload the Sketch:

   Connect your Arduino board, select the appropriate board and port from Tools, and upload the sketch.

Code Explanation

Interrupt Service Routine (ISR):

The toggleLED() function is declared as the ISR. It toggles the ledState and updates the built-in LED accordingly. Because this function is called by the hardware timer, it operates asynchronously relative to the loop() function.

Setup Function:

• Configures the built-in LED as an output.
• Starts Serial communication at 9600 baud.
• Initializes TimerOne to generate an interrupt every 1 second and attaches the ISR.

Loop Function:

• Prints the current LED state to the Serial Monitor every second.
• Demonstrates that the main loop continues to run independently while the ISR manages the LED toggling.

How to Use

Upload the Code:

Once you have uploaded the sketch to your Arduino board, open the Serial Monitor in the Arduino IDE to view the LED state messages.

Observe the Behavior:

• The built-in LED will toggle every second, managed by the timer interrupt.
• The Serial Monitor will print "LED is ON" or "LED is OFF" every second, reflecting the current state of the LED.

Understanding Asynchronous Programming

This example highlights the advantage of asynchronous programming in microcontroller applications:

Decoupling Tasks:

The LED toggling happens in the background via an interrupt, meaning the main loop can perform other tasks without waiting for the LED toggle to complete.

Efficient Resource Utilization:

By handling the LED toggle asynchronously, the microcontroller can remain responsive, and the CPU is not blocked by long wait times.

License

This project is licensed under the MIT License. See the LICENSE file for details.

Acknowledgments

• The TimerOne library for simplifying the use of hardware timers on Arduino.
• The Arduino community for continuous support and development of asynchronous programming techniques in embedded systems.