xTaskCreate() function in FreeRTOS

Introduction

The xTaskCreate() function helps you start a new task (a small program) that runs alongside other tasks in FreeRTOS. It lets your microcontroller do many things at once.

When you want your device to read a sensor and control a display at the same time.

When you need to handle button presses while also sending data over Wi-Fi.

When you want to separate different parts of your program to keep code organized and responsive.

Syntax

FreeRTOS

BaseType_t xTaskCreate(
    TaskFunction_t pvTaskCode,
    const char * const pcName,
    configSTACK_DEPTH_TYPE usStackDepth,
    void *pvParameters,
    UBaseType_t uxPriority,
    TaskHandle_t *pxCreatedTask
);

pvTaskCode is the function where your task's code lives.

usStackDepth is how much memory the task needs for its work.

Examples

This creates a task named "Task1" with priority 1 and no parameters.

FreeRTOS

xTaskCreate(
    vTaskFunction,
    "Task1",
    1000,
    NULL,
    1,
    NULL
);

This creates a task that uses sensorData and saves its handle for later control.

FreeRTOS

xTaskCreate(
    vSensorTask,
    "Sensor",
    500,
    (void *) &sensorData,
    2,
    &sensorTaskHandle
);

Sample Program

This program creates a task that prints "LED ON" and "LED OFF" every half second, simulating blinking. The scheduler runs the task.

FreeRTOS

#include "FreeRTOS.h"
#include "task.h"
#include <stdio.h>

void vBlinkTask(void *pvParameters) {
    for(;;) {
        printf("LED ON\n");
        vTaskDelay(pdMS_TO_TICKS(500));
        printf("LED OFF\n");
        vTaskDelay(pdMS_TO_TICKS(500));
    }
}

int main(void) {
    xTaskCreate(
        vBlinkTask,
        "Blink",
        1000,
        NULL,
        1,
        NULL
    );
    vTaskStartScheduler();
    for(;;); // Should never reach here
    return 0;
}

Important Notes

Always check the return value of xTaskCreate() to ensure the task was created successfully.

Stack size depends on what your task does; too small causes crashes, too big wastes memory.

Task priority controls which task runs first when multiple are ready.

Summary

xTaskCreate() starts a new task in FreeRTOS.

You give it the task function, name, stack size, parameters, priority, and a place to store the task handle.

It helps your device do many things at once smoothly.