/* FreeRTOS.org V5.1.2 - Copyright (C) 2003-2009 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. *************************************************************************** *************************************************************************** * * * Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation * * * * This is a concise, step by step, 'hands on' guide that describes both * * general multitasking concepts and FreeRTOS specifics. It presents and * * explains numerous examples that are written using the FreeRTOS API. * * Full source code for all the examples is provided in an accompanying * * .zip file. * * * *************************************************************************** *************************************************************************** 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. */ /* * THIS DEMO APPLICATION REQUIRES A LOOPBACK CONNECTOR TO BE FITTED TO THE PIC * USART PORT - connect pin 2 to pin 3 on J2. * * Instead of the normal single demo application, the PIC18F demo is split * into several smaller programs of which this is the third. This enables the * demo's to be executed on the RAM limited 40 pin devices. The 64 and 80 pin * devices require a more costly development platform and are not so readily * available. * * The RTOSDemo3 project is configured for a PIC18F452 device. Main3.c starts * 5 tasks (including the idle task). * * The first task repeatedly transmits a string of characters on the PIC USART * port. The second task receives the characters, checking that the correct * sequence is maintained (i.e. what is transmitted is identical to that * received). Each transmitted and each received character causes an LED to * flash. See demo/common/minimal/comtest. c for more information. * * The third task continuously performs a 32 bit calculation. This is a good * test of the context switch mechanism as the 8 bit architecture requires * the use of several file registers to perform the 32 bit operations. See * demo/common/minimal/integer. c for more information. * * The third task is the check task. This periodically checks that the other * tasks are still running and have not experienced any errors. If no errors * have been reported by either the comms or integer tasks an LED is flashed * with a frequency mainNO_ERROR_CHECK_PERIOD. If an error is discovered the * frequency is increased to mainERROR_FLASH_RATE. * * The check task also provides a visual indication of a system reset by * flashing the one remaining LED (mainRESET_LED) when it starts. After * this initial flash mainRESET_LED should remain off. * * http://www.FreeRTOS.org contains important information on the use of the * PIC18F port. */ /* Changes from V2.0.0 + Delay periods are now specified using variables and constants of portTickType rather than unsigned portLONG. */ /* Scheduler include files. */ #include "FreeRTOS.h" #include "task.h" /* Demo app include files. */ #include "partest.h" #include "serial.h" #include "comtest.h" #include "integer.h" /* Priority definitions for the LED tasks. Other tasks just use the idle priority. */ #define mainCOMM_TEST_PRIORITY ( tskIDLE_PRIORITY + ( unsigned portBASE_TYPE ) 2 ) #define mainCHECK_TASK_PRIORITY ( tskIDLE_PRIORITY + ( unsigned portBASE_TYPE ) 3 ) /* The period between executions of the check task before and after an error has been discovered. If an error has been discovered the check task runs more frequently - increasing the LED flash rate. */ #define mainNO_ERROR_CHECK_PERIOD ( ( portTickType ) 1000 / portTICK_RATE_MS ) #define mainERROR_CHECK_PERIOD ( ( portTickType ) 100 / portTICK_RATE_MS ) /* The period for which mainRESET_LED remain on every reset. */ #define mainRESET_LED_PERIOD ( ( portTickType ) 500 / portTICK_RATE_MS ) /* The LED that is toggled whenever a character is transmitted. mainCOMM_TX_RX_LED + 1 will be toggled every time a character is received. */ #define mainCOMM_TX_RX_LED ( ( unsigned portBASE_TYPE ) 2 ) /* The LED that is flashed by the check task at a rate that indicates the error status. */ #define mainCHECK_TASK_LED ( ( unsigned portBASE_TYPE ) 1 ) /* The LED that is flashed once upon every reset. */ #define mainRESET_LED ( ( unsigned portBASE_TYPE ) 0 ) /* Constants required for the communications. */ #define mainCOMMS_QUEUE_LENGTH ( ( unsigned portBASE_TYPE ) 5 ) #define mainBAUD_RATE ( ( unsigned portLONG ) 57600 ) /*-----------------------------------------------------------*/ /* * Task function which periodically checks the other tasks for errors. Flashes * an LED at a rate that indicates whether an error has ever been detected. */ static void vErrorChecks( void *pvParameters ); /*-----------------------------------------------------------*/ /* Creates the tasks, then starts the scheduler. */ void main( void ) { /* Initialise the required hardware. */ vParTestInitialise(); /* Initialise the block memory allocator. */ vPortInitialiseBlocks(); /* Start the standard comtest tasks as defined in demo/common/minimal. */ vAltStartComTestTasks( mainCOMM_TEST_PRIORITY, mainBAUD_RATE, mainCOMM_TX_RX_LED ); /* Start the standard 32bit calculation task as defined in demo/common/minimal. */ vStartIntegerMathTasks( tskIDLE_PRIORITY ); /* Start the check task defined in this file. */ xTaskCreate( vErrorChecks, ( const portCHAR * const ) "Check", configMINIMAL_STACK_SIZE, NULL, mainCHECK_TASK_PRIORITY, NULL ); /* Start the scheduler. This will never return. */ vTaskStartScheduler(); } /*-----------------------------------------------------------*/ static void vErrorChecks( void *pvParameters ) { portTickType xDelayTime = mainNO_ERROR_CHECK_PERIOD; volatile unsigned portLONG ulDummy = 3UL; /* Toggle the LED so we can see when a reset occurs. */ vParTestSetLED( mainRESET_LED, pdTRUE ); vTaskDelay( mainRESET_LED_PERIOD ); vParTestSetLED( mainRESET_LED, pdFALSE ); /* Cycle for ever, delaying then checking all the other tasks are still operating without error. */ for( ;; ) { /* Wait until it is time to check the other tasks. */ vTaskDelay( xDelayTime ); /* Perform an integer calculation - just to ensure the registers get used. The result is not important. */ ulDummy *= 3UL; /* Check all the other tasks are running, and running without ever having an error. The delay period is lowered if an error is reported, causing the LED to flash at a higher rate. */ if( xAreIntegerMathsTaskStillRunning() == pdFALSE ) { xDelayTime = mainERROR_CHECK_PERIOD; } if( xAreComTestTasksStillRunning() == pdFALSE ) { xDelayTime = mainERROR_CHECK_PERIOD; } /* Flash the LED for visual feedback. The rate of the flash will indicate the health of the system. */ vParTestToggleLED( mainCHECK_TASK_LED ); } } /*-----------------------------------------------------------*/