Quality RTOS & Embedded Software

 Real time embedded FreeRTOS RSS feed 
Quick Start Supported MCUs PDF Books Trace Tools Ecosystem


LPC1768 xTaskCreate() only possible in main()-function?

Posted by *anonymous on October 27, 2013


have the xTaskCreate()-function always be started out of the main()-function? I cant start both tasks by using my DCLTASK()-function in similar way to the code snippet below.

I assume there is a problem with my DCLTASK()-function because if I will use the xTaskCreate()-function out from the main()-function, everything works fine

Can someone give me a hint?

# header file
struct rtosTask
    pdTASK_CODE pvTaskCode;
    signed portCHAR pcName;
    unsigned portSHORT usStackDepth;
    void *pvParameters;
    unsigned portBASE_TYPE uxPriority;
    xTaskHandle *pxCreatedTask;

typedef struct rtosTask RTOSTASK;

# function DCLTASK
xTaskCreate(task.pvTaskCode, task.pcName, task.usStackDepth, task.pvParameters, task.uxPriority, task.pxCreatedTask);
# main()-function
RTOSTASK task1, task2;
// Task 1
xTaskHandle xHandle1;
task1.pcName = "Task1";
task1.pvTaskCode = vTask1;
task1.uxPriority = 1;
task1.pxCreatedTask = NULL;
task1.usStackDepth = 1000;
task1.pvParameters = NULL;

// Task 2
xTaskHandle xHandle2;
task2.pcName = "Task2";
task2.pvTaskCode = vTask2;
task2.uxPriority = 2;
task2.pxCreatedTask = NULL;
task2.usStackDepth = 1000;
task2.pvParameters = NULL;

// dont work!
// DCLTASK(task1);
// DCLTASK(task2);

// works! but I dont understand the difference to DCLTASK()
xTaskCreate(task1.pvTaskCode, task1.pcName, task1.usStackDepth, task1.pvParameters, task1.uxPriority, task1.pxCreatedTask);
xTaskCreate(task2.pvTaskCode, task2.pcName, task2.usStackDepth, task2.pvParameters, task2.uxPriority, task2.pxCreatedTask);

LPC1768 xTaskCreate() only possible in main()-function?

Posted by richard_damon on October 27, 2013

Are you sure the tasks are being created? One big thing to note is that your DCLTASK will get the RTOSTASK structure BY VALUE (i.e. a copy), so that the anything set by it in xTaskCreate will be thrown away.

LPC1768 xTaskCreate() only possible in main()-function?

Posted by *anonymous on October 27, 2013

You are right! Maybe it's not the most efficient way to program MCUs but if I create only one task (by using DCLTASK) then it works. Same procedure with two tasks, no chance ...

[ Back to the top ]    [ About FreeRTOS ]    [ Privacy ]    [ Sitemap ]    [ ]

Copyright (C) Amazon Web Services, Inc. or its affiliates. All rights reserved.

Latest News

NXP tweet showing LPC5500 (ARMv8-M Cortex-M33) running FreeRTOS.

Version 10.1.1 of the FreeRTOS kernel is available for immediate download. MIT licensed.

View a recording of the "OTA Update Security and Reliability" webinar, presented by TI and AWS.


FreeRTOS and other embedded software careers at AWS.

FreeRTOS Partners

ARM Connected RTOS partner for all ARM microcontroller cores

Espressif ESP32

IAR Partner

Microchip Premier RTOS Partner

RTOS partner of NXP for all NXP ARM microcontrollers


STMicro RTOS partner supporting ARM7, ARM Cortex-M3, ARM Cortex-M4 and ARM Cortex-M0

Texas Instruments MCU Developer Network RTOS partner for ARM and MSP430 microcontrollers

OpenRTOS and SafeRTOS

Xilinx Microblaze and Zynq partner