Difference between revisions of "Embedded System Tutorial FreeRTOS"
From Embedded Systems Learning Academy
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| + | Socialledge is moving to two portals. | ||
| + | * The Wiki will remain here for general references about the SJ-One board, and to document student reports. | ||
| + | * The bookstack will now be used for SJSU assignments | ||
| + | |||
| + | [http://books.socialledge.com/books/embedded-drivers-real-time-operating-systems/page/freertos-tasks This article has been moved here] | ||
| + | |||
| + | <!-- | ||
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The objective of this assignment is to show you how to create a FreeRTOS task a few different ways. The [[FreeRTOS Tutorial]] is definitely a must read before going through this lesson. | The objective of this assignment is to show you how to create a FreeRTOS task a few different ways. The [[FreeRTOS Tutorial]] is definitely a must read before going through this lesson. | ||
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=== C++ Task === | === C++ Task === | ||
<syntaxhighlight lang="cpp"> | <syntaxhighlight lang="cpp"> | ||
| + | |||
| + | /// IDs used for getSharedObject() and addSharedObject() | ||
| + | typedef enum { | ||
| + | shared_SensorQueueId, | ||
| + | } sharedHandleId_t; | ||
| + | |||
| + | /// Orientation type enumeration | ||
| + | typedef enum { | ||
| + | invalid, | ||
| + | left, | ||
| + | right, | ||
| + | } orientation_t; | ||
| + | |||
class orient_compute : public scheduler_task | class orient_compute : public scheduler_task | ||
{ | { | ||
public: | public: | ||
| − | orient_compute(uint8_t priority) : scheduler_task("compute", | + | orient_compute(uint8_t priority) : scheduler_task("compute", 2048, priority) |
{ | { | ||
| − | QueueHandle_t my_queue = xQueueCreate(1, sizeof( | + | /* We save the queue handle by using addSharedObject() */ |
| − | addSharedObject( | + | QueueHandle_t my_queue = xQueueCreate(1, sizeof(orientation_t)); |
| + | addSharedObject(shared_SensorQueueId, my_queue); | ||
} | } | ||
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{ | { | ||
/* Compute orientation here, and send it to the queue once a second */ | /* Compute orientation here, and send it to the queue once a second */ | ||
| − | + | orientation_t orientation = invalid; | |
| − | xQueueSend(getSharedObject( | + | xQueueSend(getSharedObject(shared_SensorQueueId), &orientation, portMAX_DELAY); |
| + | |||
vTaskDelay(1000); | vTaskDelay(1000); | ||
return true; | return true; | ||
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{ | { | ||
public: | public: | ||
| − | orient_process (uint8_t priority) : scheduler_task("process", | + | orient_process (uint8_t priority) : scheduler_task("process", 2048, priority) |
{ | { | ||
/* Nothing to init */ | /* Nothing to init */ | ||
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bool run(void *p) | bool run(void *p) | ||
{ | { | ||
| + | /* We first get the queue handle the other task added using addSharedObject() */ | ||
| + | orientation_t orientation = invalid; | ||
| + | QueueHandle_t qid = getSharedObject(shared_SensorQueueId); | ||
| + | |||
/* Sleep the task forever until an item is available in the queue */ | /* Sleep the task forever until an item is available in the queue */ | ||
| − | + | if (xQueueReceive(qid, &orientation, portMAX_DELAY)) | |
| − | if (xQueueReceive( | ||
{ | { | ||
} | } | ||
| + | |||
return true; | return true; | ||
} | } | ||
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This assignment is based on SJ-One board, but you can alter the requirement to fit your own hardware. | This assignment is based on SJ-One board, but you can alter the requirement to fit your own hardware. | ||
# Create a task (task1) that computes the orientation of the board. | # Create a task (task1) that computes the orientation of the board. | ||
| + | #: You can use the acceleration sensor to figure out the orientation of the board | ||
#: Send the orientation enumeration, such as "up", "down", "left", "right" to a queue every 1 second | #: Send the orientation enumeration, such as "up", "down", "left", "right" to a queue every 1 second | ||
# Create another task (task2) that waits on the queued item | # Create another task (task2) that waits on the queued item | ||
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#: Use the same priority for both tasks, and note down the order of the print-outs | #: Use the same priority for both tasks, and note down the order of the print-outs | ||
#: Use higher priority for the receiving task, and note down the order of the print-outs. | #: Use higher priority for the receiving task, and note down the order of the print-outs. | ||
| − | # Create a terminal | + | # Create a terminal command: "orientation on" and "orientation off" |
#: If orientation is commanded on, resume the task1, otherwise suspend it | #: If orientation is commanded on, resume the task1, otherwise suspend it | ||
#: See code below on hints of how this command can get control of another task. | #: See code below on hints of how this command can get control of another task. | ||
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} | } | ||
</syntaxhighlight> | </syntaxhighlight> | ||
| + | --> | ||
Latest revision as of 20:11, 25 January 2019
Socialledge is moving to two portals.
- The Wiki will remain here for general references about the SJ-One board, and to document student reports.
- The bookstack will now be used for SJSU assignments
This article has been moved here
