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Message queue FreeRTOS learning warehouse address: https://gitee.com/killerp/free-rtos_-study Message queue is the basic data structure of RTOS, which is used for data transmission between tasks and between tasks and interrupts. When message queuing is not used, if you want to transfer data between two tasks, you must transfer it throug ...

1. Task create and delete API functions functiondescribexTaskCreateCreate a task using a dynamic methodxTaskCreateStaticCreate a task using a static methodxTaskDelete()Delete a task xTaskCreate This function is used to create a task. The task requires RAM to save the status information related to the task (task control block) The task also ...

0 Preface @ Author : Dargon @ Record Date : 2021/07/13 @ Reference Book : `FreeRTOS Detailed source code and application development`，`ARM Cortex-M3 And Cortex-M4 Authoritative guide`，`B Standing point atom FreeRTOS Explanation video` @ Purpose : Learning about punctual atoms miniFly，The flight control is based on Free ...

FreeRTOS list List NOUN List List_t typedef struct xLIST { listFIRST_LIST_INTEGRITY_CHECK_VALUE /*< Set to a known value if configUSE_LIST_DATA_INTEGRITY_CHECK_BYTES is set to 1. */ configLIST_VOLATILE UBaseType_t uxNumberOfItems; ListItem_t * configLIST_VOLATILE pxIndex; /*< Used to walk through the list. Points to the last it ...

FreeRTOS kernel control FreeRTOS has some functions only for the kernel, which are generally not allowed by applications. These are the system kernel functions. Kernel control function API taskYIELD(): task switching taskENTER_CRITICAL(): enter the critical area, which is used in the task taskEXIT_CRITICAL(): exit the critical area, which is ...

FreeRTOS task creation and suspension 1 task related concepts Task status Running state When a task is running, it can be said that the task is running. If it is a single core processor, there is always only one task in progress at any time. Ready Tasks in the ready state are those that are ready (these tasks are not blocked or suspended) ...

  embedded real-time systems need to respond to events generated by the whole system environment. These events have different requirements for processing time and response time. Events are usually detected by interrupt, and the processing capacity in interrupt service routine (ISR) should be as short as possible.   note: only "Fr ...

In the "message queue" article, we once buried a foreshadowing, that is, the message delivery and synchronization of tasks in FreeRTOS are all through message queue. Can't it be through global variables? The answer is yes, but this will cause delayed response. If you use global variables, you can only poll, which will inevitably lose ...

preface Using semaphores can complete the synchronization between tasks, but using semaphores to synchronize tasks can only synchronize with a single event or task. Sometimes a task may need to be synchronized with multiple events or tasks, and the semaphore is powerless. FreeRTOS provides an optional solution for this, which is the event ...

1, Message queue Message queue is a data structure commonly used for inter task communication. Queue can transfer information between tasks, interrupts and tasks. Both read and write queues support timeout mechanism. 1. Create queue QueueHandle_t xQueueCreate( UBaseType_t uxQueueLength,//queue length UBaseType_t uxItemSize );//Th ...