Dear All,     I am working on STR9-Angilia-FreeRTOs Project.     I am creating 9 Tasks having same priority( 5 ). configMAX_PRIORITY is 8.     Stack size are     1) Stack sizes of 4 Tasks are 100.     2) Stack sizes of other 5 Tasks are 400. ( 4 of these Tasks are multiple instances of one Task )     But one of the above Task which having 100 Stack Size is not getting created due to stack size.     As per site documentation higher the value of configMAX_PRIORITY more RAM will     be required by Kernel. Therefore I kept priorities of All Tasks to 1 and configMAX_PRIORITY set to 2. But found same result.     I don’t know why stack size is creating problem if STR9 is having 96K RAM ?     How should I calculate Stack sizes ?     I know that we have to add sizes all variables used in Task & in related functions.     Am I right or tell me how to calculate it exactly ?     Please help me in this issue.     Thanks, Sachin D. Bhujbal        

If you are using heap_1.c or heap_2.c then increase the value of configTOTAL_HEAP_SPACE in FreeRTOSConfig.h.

Thanks Dave,      Problem is solved after increasing Heap Size., I read it in document that it is ram size available to Kernel. But can You explain me in detail about Heap & its use ? Please answer !

Did you read this http://www.freertos.org/a00111.html ?