/* FreeRTOS.org V5.0.4 - Copyright (C) 2003-2008 Richard Barry. This file is part of the FreeRTOS.org distribution. FreeRTOS.org is free software; you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. FreeRTOS.org 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. See the GNU General Public License for more details. You should have received a copy of the GNU General Public License along with FreeRTOS.org; if not, write to the Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA A special exception to the GPL can be applied should you wish to distribute a combined work that includes FreeRTOS.org, without being obliged to provide the source code for any proprietary components. See the licensing section of http://www.FreeRTOS.org for full details of how and when the exception can be applied. *************************************************************************** *************************************************************************** * * * SAVE TIME AND MONEY! We can port FreeRTOS.org to your own hardware, * * and even write all or part of your application on your behalf. * * See http://www.OpenRTOS.com for details of the services we provide to * * expedite your project. * * * *************************************************************************** *************************************************************************** Please ensure to read the configuration and relevant port sections of the online documentation. http://www.FreeRTOS.org - Documentation, latest information, license and contact details. http://www.SafeRTOS.com - A version that is certified for use in safety critical systems. http://www.OpenRTOS.com - Commercial support, development, porting, licensing and training services. */ /* FreeRTOS.org includes. */ #include "FreeRTOS_ARM.h" //#include "task.h" //#include "semphr.h" //#include "portasm.h" /* Demo includes. */ #include "basic_io_arm.h" /* Compiler includes. */ //#include /* The tasks to be created. */ static void vHandlerTask( void *pvParameters ); static void vPeriodicTask( void *pvParameters ); /* The service routine for the interrupt. This is the interrupt that the task will be synchronized with. */ static void vExampleInterruptHandler( void ); /*-----------------------------------------------------------*/ /* Declare a variable of type xSemaphoreHandle. This is used to reference the semaphore that is used to synchronize a task with an interrupt. */ xSemaphoreHandle xCountingSemaphore; // pins to generate interrupts - they must be connected const uint8_t inputPin = 2; const uint8_t outputPin = 3; void setup( void ) { Serial.begin(9600); /* Before a semaphore is used it must be explicitly created. In this example a counting semaphore is created. The semaphore is created to have a maximum count value of 10, and an initial count value of 0. */ xCountingSemaphore = xSemaphoreCreateCounting( 10, 0 ); /* Install the interrupt handler. */ // _dos_setvect( 0x82, vExampleInterruptHandler ); pinMode(outputPin, OUTPUT); pinMode(inputPin, INPUT); attachInterrupt(inputPin, vExampleInterruptHandler, RISING); /* Check the semaphore was created successfully. */ if( xCountingSemaphore != NULL ) { /* Create the 'handler' task. This is the task that will be synchronized with the interrupt. The handler task is created with a high priority to ensure it runs immediately after the interrupt exits. In this case a priority of 3 is chosen. */ xTaskCreate( vHandlerTask, (signed char*)"Handler", 200, NULL, 3, NULL ); /* Create the task that will periodically generate a software interrupt. This is created with a priority below the handler task to ensure it will get preempted each time the handler task exist the Blocked state. */ xTaskCreate( vPeriodicTask, (signed char*)"Periodic", 200, NULL, 1, NULL ); /* Start the scheduler so the created tasks start executing. */ vTaskStartScheduler(); } /* If all is well we will never reach here as the scheduler will now be running the tasks. If we do reach here then it is likely that there was insufficient heap memory available for a resource to be created. */ for( ;; ); // return 0; } /*-----------------------------------------------------------*/ static void vHandlerTask( void *pvParameters ) { /* As per most tasks, this task is implemented within an infinite loop. */ for( ;; ) { /* Use the semaphore to wait for the event. The semaphore was created before the scheduler was started so before this task ran for the first time. The task blocks indefinitely meaning this function call will only return once the semaphore has been successfully obtained - so there is no need to check the returned value. */ xSemaphoreTake( xCountingSemaphore, portMAX_DELAY ); /* To get here the event must have occurred. Process the event (in this case we just print out a message). */ vPrintString( "Handler task - Processing event.\r\n" ); } } /*-----------------------------------------------------------*/ static void vPeriodicTask( void *pvParameters ) { /* As per most tasks, this task is implemented within an infinite loop. */ for( ;; ) { /* This task is just used to 'simulate' an interrupt. This is done by periodically generating a software interrupt. */ vTaskDelay( 500 / portTICK_RATE_MS ); /* Generate the interrupt, printing a message both before hand and afterwards so the sequence of execution is evident from the output. */ vPrintString( "Perodic task - About to generate an interrupt.\r\n" ); // __asm{ int 0x82 } digitalWrite(outputPin, LOW); digitalWrite(outputPin, HIGH); vPrintString( "Periodic task - Interrupt generated.\r\n\r\n\r\n" ); } } /*-----------------------------------------------------------*/ static void vExampleInterruptHandler( void ) { static portBASE_TYPE xHigherPriorityTaskWoken; xHigherPriorityTaskWoken = pdFALSE; /* 'Give' the semaphore multiple times. The first will unblock the handler task, the following 'gives' are to demonstrate that the semaphore latches the events to allow the handler task to process them in turn without any events getting lost. This simulates multiple interrupts being taken by the processor, even though in this case the events are simulated within a single interrupt occurrence.*/ xSemaphoreGiveFromISR( xCountingSemaphore, &xHigherPriorityTaskWoken ); xSemaphoreGiveFromISR( xCountingSemaphore, &xHigherPriorityTaskWoken ); xSemaphoreGiveFromISR( xCountingSemaphore, &xHigherPriorityTaskWoken ); if( xHigherPriorityTaskWoken == pdTRUE ) { /* Giving the semaphore unblocked a task, and the priority of the unblocked task is higher than the currently running task - force a context switch to ensure that the interrupt returns directly to the unblocked (higher priority) task. NOTE: The syntax for forcing a context switch is different depending on the port being used. Refer to the examples for the port you are using for the correct method to use! */ // portSWITCH_CONTEXT(); vPortYield(); } } //--------------------------------------------------------------- void loop() {}