FreeRTOS Xilinx Vivado: Hello World!
4 likes4,499 views
This document describes a "Hello World" example using FreeRTOS on an embedded operating system. It creates two tasks, a Tx task that sends the string "Hello World" to a queue every second, and an Rx task that receives the string from the queue and prints it. A timer is also created that expires after 10 seconds, checks if the Rx task has received enough messages, and prints whether the example passed or failed before deleting the two tasks.
![/* The queue used by the Tx and Rx tasks, as described at the top of this file. */
static TaskHandle_t xTxTask;
static TaskHandle_t xRxTask;
static QueueHandle_t xQueue = NULL;
static TimerHandle_t xTimer = NULL;
char HWstring[15] = "Hello World";
long RxtaskCntr = 0;
Vincent Claes](https://image.slidesharecdn.com/freertoscourse1-161121201348/85/FreeRTOS-Xilinx-Vivado-Hello-World-5-320.jpg)
![xQueue = xQueueCreate(1, sizeof( HWstring ) );
/* 1 : One place in queue */
/* sizeof (HWstring) : place in queue can hold HWstring */
/* char HWstring[15] : “Hello World”; */
Vincent Claes](https://image.slidesharecdn.com/freertoscourse1-161121201348/85/FreeRTOS-Xilinx-Vivado-Hello-World-10-320.jpg)
![prvRxTask
static void prvRxTask( void *pvParameters )
{
char Recdstring[15] = "";
for( ;; )
{
xQueueReceive( xQueue, Recdstring, portMAX_DELAY );
xil_printf( "Rx task received string from Tx task: %srn", Recdstring );
RxtaskCntr++;
}
}
Vincent Claes](https://image.slidesharecdn.com/freertoscourse1-161121201348/85/FreeRTOS-Xilinx-Vivado-Hello-World-12-320.jpg)
FreeRTOS Xilinx Vivado: Hello World!
- 1. Embedded Operating System: FreeRTOS: Hello World! Vincent Claes
- 2. Hello World Example in Xilinx Vivado SDK (FreeRTOS) /* FreeRTOS includes. */ #include "FreeRTOS.h" #include "task.h" #include "queue.h" #include "timers.h" /* Xilinx includes. */ #include "xil_printf.h" #include "xparameters.h" Vincent Claes
- 3. #define TIMER_ID 1 #define DELAY_10_SECONDS 10000UL #define DELAY_1_SECOND 1000UL #define TIMER_CHECK_THRESHOLD 9 Vincent Claes
- 4. /* The Tx and Rx tasks as described at the top of this file. */ static void prvTxTask( void *pvParameters ); static void prvRxTask( void *pvParameters ); static void vTimerCallback( TimerHandle_t pxTimer ); Vincent Claes
- 5. /* The queue used by the Tx and Rx tasks, as described at the top of this file. */ static TaskHandle_t xTxTask; static TaskHandle_t xRxTask; static QueueHandle_t xQueue = NULL; static TimerHandle_t xTimer = NULL; char HWstring[15] = "Hello World"; long RxtaskCntr = 0; Vincent Claes
- 6. int main( void ) { /* pdMS_TO_TICKS: Converts a time in milliseconds to a time in ticks. */ const TickType_t x10seconds = pdMS_TO_TICKS(DELAY_10_SECONDS ); xil_printf( "Hello from Freertos example mainrn" ); xTaskCreate( prvTxTask, ( const char * ) "Tx", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, &xTxTask ); xTaskCreate( prvRxTask, ( const char * ) "GB", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, &xRxTask ); Vincent Claes
- 7. xTaskCreate( prvTxTask, ( const char * ) "Tx", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY, &xTxTask ); /* prvTxTask : function that implements the task */ /* “TX” : Name for the task */ /* configMINIMAL_STACK_SIZE : stack allocated tot he task */ /* NULL : parameter not used */ /* tskIDLE_PRIORITY : task runs at idle priority */ /* &xTxTask : TX Taskhandler */ Vincent Claes
- 8. xTaskCreate( prvRxTask, ( const char * ) "GB", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, &xRxTask ); /* prvRxTask : function that implements the task */ /* “GB” : Name for the task */ /* configMINIMAL_STACK_SIZE : stack allocated tot he task */ /* NULL : parameter not used */ /* tskIDLE_PRIORITY : task runs at idle priority +1 */ /* &xRxTask : RX Taskhandler */ Vincent Claes
- 9. xTaskCreate( prvRxTask, ( const char * ) "GB", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, &xRxTask ); xQueue = xQueueCreate(1, sizeof( HWstring ) ); /* Check if queue was created */ configASSERT(xQueue); xTimer = xTimerCreate( (const char *) "Timer", x10seconds, pdFALSE, (void *) TIMER_ID, vTimerCallback); configASSERT(xTimer); Vincent Claes
- 10. xQueue = xQueueCreate(1, sizeof( HWstring ) ); /* 1 : One place in queue */ /* sizeof (HWstring) : place in queue can hold HWstring */ /* char HWstring[15] : “Hello World”; */ Vincent Claes
- 11. xTimer = xTimerCreate( (const char *) "Timer", x10seconds, pdFALSE, (void *) TIMER_ID, vTimerCallback); /* “Timer” : Name of Timer */ /* x10seconds : expires after 10 seconds */ /* pdFALSE : Don’t autoreload */ /* TIMER_ID : Timer identifier */ /* vTimerCallback : Timer callback function */ Vincent Claes
- 12. prvRxTask static void prvRxTask( void *pvParameters ) { char Recdstring[15] = ""; for( ;; ) { xQueueReceive( xQueue, Recdstring, portMAX_DELAY ); xil_printf( "Rx task received string from Tx task: %srn", Recdstring ); RxtaskCntr++; } } Vincent Claes
- 13. xQueueReceive( xQueue, Recdstring, portMAX_DELAY ); /* xQueue : Queue being read */ /* Recdstring : Data read intro this address */ /* portMAX_DELAY : wait without timeout for data */ Vincent Claes
- 14. prvTxTask static void prvTxTask( void *pvParameters ) { const TickType_t x1second = pdMS_TO_TICKS( DELAY_1_SECOND ); for( ;; ) { /* Delay for 1 second. */ vTaskDelay( x1second ); xQueueSend( xQueue, HWstring, 0UL ); } } Vincent Claes
- 15. xQueueSend( xQueue, HWstring, 0UL ); /* xQueue : Queue written to */ /* Hwstring : Address data being sent */ /* 0UL : block time */ Vincent Claes
- 16. vTimerCallback static void vTimerCallback( TimerHandle_t pxTimer ) { long lTimerId; configASSERT( pxTimer ); lTimerId = ( long ) pvTimerGetTimerID( pxTimer ); if (lTimerId != TIMER_ID) { xil_printf("FreeRTOS Hello World Example FAILED"); } if (RxtaskCntr >= TIMER_CHECK_THRESHOLD) { xil_printf("FreeRTOS Hello World Example PASSED"); } else { xil_printf("FreeRTOS Hello World Example FAILED"); } vTaskDelete( xRxTask ); vTaskDelete( xTxTask ); } Vincent Claes