In embedded development, multitasking is key to improving system efficiency and functionality. For resource-constrained microcontrollers, traditional preemptive multitasking frameworks (like FreeRTOS) can be overly complex and resource-intensive. In this case, the lightweight cooperative multitasking scheduler TaskScheduler becomes an ideal choice.

Introduction to TaskScheduler

TaskScheduler is a library that provides cooperative multitasking capabilities for microcontrollers such as Arduino, ESPx, STM32, etc. It offers a simple and easy-to-use API that allows you to easily create, manage, and execute multiple tasks without needing to delve into the complexities of preemptive scheduling mechanisms.

Why Choose Cooperative Multitasking?

Compared to preemptive multitasking, cooperative multitasking has the following advantages:

• • Simplified Programming: Developers can focus solely on task logic without worrying about complex issues like thread synchronization and locks.

• • Resource Efficiency: Without the overhead of context switching, cooperative multitasking is lighter and more suitable for resource-constrained microcontrollers.

• • Easy Debugging: With a controllable task execution order, the debugging process becomes easier.

Main Features of TaskScheduler

• • Periodic Task Execution: You can set the frequency (in milliseconds or microseconds) and iteration count for task execution.

• • Dynamic Parameter Adjustment: You can dynamically modify the task’s execution frequency, iteration count, and callback method.

• • Event-Driven: Through state request objects, you can implement event-driven task execution.

• • Task Priority: Supports multi-level task priorities, effectively managing the execution order of different tasks.

• • CPU Load Statistics: Provides statistics on CPU load and idle time for system performance analysis.

• • Low Power Mode: When there are no tasks to execute, it can enter sleep mode to save power.

• • Thread Safety: Even when running under preemptive schedulers (like FreeRTOS), scheduling operations can still be thread-safe.

• • Cross-Platform Support: Supports various common microcontroller platforms, including Arduino, ESPx, STM32, etc.

Example Usage of TaskScheduler

Suppose you want to implement a simple LED blinking function:

#include <TaskScheduler.h>

TaskScheduler scheduler;
Task task1;

void setup() {
pinMode(LED_BUILTIN, OUTPUT);

// Create a task with a period of 500 milliseconds, callback function is blinkLED
task1.setInterval(500);
task1.setCallback(blinkLED);
scheduler.addTask(task1);
}

void loop() {
// Process other tasks
scheduler.execute();
}

void blinkLED() {
digitalWrite(LED_BUILTIN,!digitalRead(LED_BUILTIN));
}

Conclusion

TaskScheduler provides a simple and easy-to-use cooperative multitasking capability for Arduino and other microcontrollers. It effectively simplifies multitasking programming, enhances system efficiency, and reduces development difficulty. Whether it’s a simple LED blinking or a complex functionality implementation, TaskScheduler can meet your needs.

Project Address: https://github.com/arkhipenko/TaskScheduler