/* FreeRTOS V8.2.0rc1 - Copyright (C) 2014 Real Time Engineers Ltd. All rights reserved VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION. 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 on 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?". Have you defined configASSERT()? * * * * http://www.FreeRTOS.org/FAQHelp.html * * * *************************************************************************** *************************************************************************** * * * FreeRTOS provides completely free yet professionally developed, * * robust, strictly quality controlled, supported, and cross * * platform software that is more than just the market leader, it * * is the industry's de facto standard. * * * * Help yourself get started quickly while simultaneously helping * * to support the FreeRTOS project by purchasing a FreeRTOS * * tutorial book, reference manual, or both: * * http://www.FreeRTOS.org/Documentation * * * *************************************************************************** *************************************************************************** * * * Investing in training allows your team to be as productive as * * possible as early as possible, lowering your overall development * * cost, and enabling you to bring a more robust product to market * * earlier than would otherwise be possible. Richard Barry is both * * the architect and key author of FreeRTOS, and so also the world's * * leading authority on what is the world's most popular real time * * kernel for deeply embedded MCU designs. Obtaining your training * * from Richard ensures your team will gain directly from his in-depth * * product knowledge and years of usage experience. Contact Real Time * * Engineers Ltd to enquire about the FreeRTOS Masterclass, presented * * by Richard Barry: http://www.FreeRTOS.org/contact * * *************************************************************************** *************************************************************************** * * * You are receiving this top quality software for free. Please play * * fair and reciprocate by reporting any suspected issues and * * participating in the community forum: * * http://www.FreeRTOS.org/support * * * * Thank you! * * * *************************************************************************** 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.FreeRTOS.org/labs - Where new FreeRTOS products go to incubate. Come and try FreeRTOS+TCP, our new open source TCP/IP stack for FreeRTOS. http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High Integrity Systems ltd. to sell under the OpenRTOS brand. Low cost OpenRTOS licenses offer ticketed support, indemnification and commercial 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 ); } /*-----------------------------------------------------------*/