00001 /* 00002 FreeRTOS V6.0.0 - Copyright (C) 2009 Real Time Engineers Ltd. 00003 00004 *************************************************************************** 00005 * * 00006 * If you are: * 00007 * * 00008 * + New to FreeRTOS, * 00009 * + Wanting to learn FreeRTOS or multitasking in general quickly * 00010 * + Looking for basic training, * 00011 * + Wanting to improve your FreeRTOS skills and productivity * 00012 * * 00013 * then take a look at the FreeRTOS eBook * 00014 * * 00015 * "Using the FreeRTOS Real Time Kernel - a Practical Guide" * 00016 * http://www.FreeRTOS.org/Documentation * 00017 * * 00018 * A pdf reference manual is also available. Both are usually delivered * 00019 * to your inbox within 20 minutes to two hours when purchased between 8am * 00020 * and 8pm GMT (although please allow up to 24 hours in case of * 00021 * exceptional circumstances). Thank you for your support! * 00022 * * 00023 *************************************************************************** 00024 00025 This file is part of the FreeRTOS distribution. 00026 00027 FreeRTOS is free software; you can redistribute it and/or modify it under 00028 the terms of the GNU General Public License (version 2) as published by the 00029 Free Software Foundation AND MODIFIED BY the FreeRTOS exception. 00030 ***NOTE*** The exception to the GPL is included to allow you to distribute 00031 a combined work that includes FreeRTOS without being obliged to provide the 00032 source code for proprietary components outside of the FreeRTOS kernel. 00033 FreeRTOS is distributed in the hope that it will be useful, but WITHOUT 00034 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 00035 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for 00036 more details. You should have received a copy of the GNU General Public 00037 License and the FreeRTOS license exception along with FreeRTOS; if not it 00038 can be viewed here: http://www.freertos.org/a00114.html and also obtained 00039 by writing to Richard Barry, contact details for whom are available on the 00040 FreeRTOS WEB site. 00041 00042 1 tab == 4 spaces! 00043 00044 http://www.FreeRTOS.org - Documentation, latest information, license and 00045 contact details. 00046 00047 http://www.SafeRTOS.com - A version that is certified for use in safety 00048 critical systems. 00049 00050 http://www.OpenRTOS.com - Commercial support, development, porting, 00051 licensing and training services. 00052 */ 00053 00068 #include <stdlib.h> 00069 00070 /* Scheduler include files. */ 00071 #include "FreeRTOS.h" 00072 #include "task.h" 00073 00074 /* Demo program include files. */ 00075 #include "partest.h" 00076 #include "flash.h" 00077 00078 #define ledSTACK_SIZE configMINIMAL_STACK_SIZE 00079 #define ledNUMBER_OF_LEDS ( 3 ) 00080 #define ledFLASH_RATE_BASE ( ( portTickType ) 333 ) 00081 00082 /* Variable used by the created tasks to calculate the LED number to use, and 00083 the rate at which they should flash the LED. */ 00084 static volatile unsigned portBASE_TYPE uxFlashTaskNumber = 0; 00085 00086 /* The task that is created three times. */ 00087 static portTASK_FUNCTION_PROTO( vLEDFlashTask, pvParameters ); 00088 00089 /*-----------------------------------------------------------*/ 00090 00091 void vStartLEDFlashTasks( unsigned portBASE_TYPE uxPriority ) 00092 { 00093 signed portBASE_TYPE xLEDTask; 00094 00095 /* Create the three tasks. */ 00096 for( xLEDTask = 0; xLEDTask < ledNUMBER_OF_LEDS; ++xLEDTask ) 00097 { 00098 /* Spawn the task. */ 00099 xTaskCreate( vLEDFlashTask, ( signed char * ) "LEDx", ledSTACK_SIZE, NULL, uxPriority, ( xTaskHandle * ) NULL ); 00100 } 00101 } 00102 /*-----------------------------------------------------------*/ 00103 00104 static portTASK_FUNCTION( vLEDFlashTask, pvParameters ) 00105 { 00106 portTickType xFlashRate, xLastFlashTime; 00107 unsigned portBASE_TYPE uxLED; 00108 00109 /* The parameters are not used. */ 00110 ( void ) pvParameters; 00111 00112 /* Calculate the LED and flash rate. */ 00113 portENTER_CRITICAL(); 00114 { 00115 /* See which of the eight LED's we should use. */ 00116 uxLED = uxFlashTaskNumber; 00117 00118 /* Update so the next task uses the next LED. */ 00119 uxFlashTaskNumber++; 00120 } 00121 portEXIT_CRITICAL(); 00122 00123 xFlashRate = ledFLASH_RATE_BASE + ( ledFLASH_RATE_BASE * ( portTickType ) uxLED ); 00124 xFlashRate /= portTICK_RATE_MS; 00125 00126 /* We will turn the LED on and off again in the delay period, so each 00127 delay is only half the total period. */ 00128 xFlashRate /= ( portTickType ) 2; 00129 00130 /* We need to initialise xLastFlashTime prior to the first call to 00131 vTaskDelayUntil(). */ 00132 xLastFlashTime = xTaskGetTickCount(); 00133 00134 for(;;) 00135 { 00136 /* Delay for half the flash period then turn the LED on. */ 00137 vTaskDelayUntil( &xLastFlashTime, xFlashRate ); 00138 vParTestToggleLED( uxLED ); 00139 00140 /* Delay for half the flash period then turn the LED off. */ 00141 vTaskDelayUntil( &xLastFlashTime, xFlashRate ); 00142 vParTestToggleLED( uxLED ); 00143 } 00144 } /*lint !e715 !e818 !e830 Function definition must be standard for task creation. */ 00145