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/*
FreeRTOS V8.1.0 - Copyright (C) 2014 Real Time Engineers Ltd.
All rights reserved
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS provides completely free yet professionally developed, *
* robust, strictly quality controlled, supported, and cross *
* platform software that has become a de facto standard. *
* *
* Help yourself get started quickly and support the FreeRTOS *
* project by purchasing a FreeRTOS tutorial book, reference *
* manual, or both from: http://www.FreeRTOS.org/Documentation *
* *
* Thank you! *
* *
***************************************************************************
This file is part of the FreeRTOS distribution.
FreeRTOS is free software; you can redistribute it and/or modify it under
the terms of the GNU General Public License (version 2) as published by the
Free Software Foundation >>!AND MODIFIED BY!<< the FreeRTOS exception.
>>! NOTE: The modification to the GPL is included to allow you to !<<
>>! distribute a combined work that includes FreeRTOS without being !<<
>>! obliged to provide the source code for proprietary components !<<
>>! outside of the FreeRTOS kernel. !<<
FreeRTOS is distributed in the hope that it will be useful, but WITHOUT ANY
WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE. Full license text is available from the following
link: http://www.freertos.org/a00114.html
1 tab == 4 spaces!
***************************************************************************
* *
* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong?" *
* *
* http://www.FreeRTOS.org/FAQHelp.html *
* *
***************************************************************************
http://www.FreeRTOS.org - Documentation, books, training, latest versions,
license and Real Time Engineers Ltd. contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool, a DOS
compatible FAT file system, and our tiny thread aware UDP/IP stack.
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
licenses offer ticketed support, indemnification and middleware.
http://www.SafeRTOS.com - High Integrity Systems also provide a safety
engineered and independently SIL3 certified version for use in safety and
mission critical applications that require provable dependability.
1 tab == 4 spaces!
*/
/*
* This file defines the button push task and ISR as described at the top of
* main.c. The ISR is called from a wrapper function defined in ButtonISR.s26.
*/
/* Kernel includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "semphr.h"
/* The LED output used by the button push task. */
#define butLED1 P7_bit.no7
/* A short delay used for button debouncing. */
#define butDEBOUNCE_DELAY ( 200 / portTICK_PERIOD_MS )
/* The semaphore used to synchronise the button push task with the interrupt. */
static SemaphoreHandle_t xButtonSemaphore;
/*
* The definition of the button task itself. See the comments at the top of
* main.c.
*/
void vButtonTask( void *pvParameters )
{
/* Ensure the semaphore is created before it gets used. */
vSemaphoreCreateBinary( xButtonSemaphore );
for( ;; )
{
/* Block on the semaphore to wait for an interrupt event. The semaphore
is 'given' from vButtonISRHandler() below. Using portMAX_DELAY as the
block time will cause the task to block indefinitely provided
INCLUDE_vTaskSuspend is set to 1 in FreeRTOSConfig.h. */
xSemaphoreTake( xButtonSemaphore, portMAX_DELAY );
/* The button must have been pushed for this line to be executed.
Simply toggle the LED. */
butLED1 = !butLED1;
/* Wait a short time then clear any pending button pushes as a crude
method of debouncing the switch. xSemaphoreTake() uses a block time of
zero this time so it returns immediately rather than waiting for the
interrupt to occur. */
vTaskDelay( butDEBOUNCE_DELAY );
xSemaphoreTake( xButtonSemaphore, 0 );
}
}
/*-----------------------------------------------------------*/
/*
* The C portion of the interrupt handler. Interrupts are triggered by pushing
* the button on the target board. This interrupt can cause a context switch
* so has an assembly file wrapper defined within ButtonISR.s26.
*/
void vButtonISRHandler( void )
{
short sHigherPriorityTaskWoken = pdFALSE;
/* 'Give' the semaphore to unblock the button task. */
xSemaphoreGiveFromISR( xButtonSemaphore, &sHigherPriorityTaskWoken );
/* If giving the semaphore unblocked a task, and the unblocked task has a
priority that is higher than the currently running task, then
sHigherPriorityTaskWoken will have been set to pdTRUE. Passing a pdTRUE
value to portYIELD_FROM_ISR() will cause this interrupt to return directly
to the higher priority unblocked task. */
portYIELD_FROM_ISR( sHigherPriorityTaskWoken );
}
/*-----------------------------------------------------------*/
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