2 FreeRTOS V7.2.0 - Copyright (C) 2012 Real Time Engineers Ltd.
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5 ***************************************************************************
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7 * FreeRTOS tutorial books are available in pdf and paperback. *
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8 * Complete, revised, and edited pdf reference manuals are also *
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11 * Purchasing FreeRTOS documentation will not only help you, by *
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12 * ensuring you get running as quickly as possible and with an *
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13 * in-depth knowledge of how to use FreeRTOS, it will also help *
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14 * the FreeRTOS project to continue with its mission of providing *
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15 * professional grade, cross platform, de facto standard solutions *
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16 * for microcontrollers - completely free of charge! *
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18 * >>> See http://www.FreeRTOS.org/Documentation for details. <<< *
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20 * Thank you for using FreeRTOS, and thank you for your support! *
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22 ***************************************************************************
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25 This file is part of the FreeRTOS distribution.
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27 FreeRTOS is free software; you can redistribute it and/or modify it under
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28 the terms of the GNU General Public License (version 2) as published by the
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29 Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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30 >>>NOTE<<< The modification to the GPL is included to allow you to
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31 distribute a combined work that includes FreeRTOS without being obliged to
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32 provide the source code for proprietary components outside of the FreeRTOS
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33 kernel. FreeRTOS is distributed in the hope that it will be useful, but
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34 WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY
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35 or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
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36 more details. You should have received a copy of the GNU General Public
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37 License and the FreeRTOS license exception along with FreeRTOS; if not it
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38 can be viewed here: http://www.freertos.org/a00114.html and also obtained
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39 by writing to Richard Barry, contact details for whom are available on the
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44 ***************************************************************************
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46 * Having a problem? Start by reading the FAQ "My application does *
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47 * not run, what could be wrong? *
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49 * http://www.FreeRTOS.org/FAQHelp.html *
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51 ***************************************************************************
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54 http://www.FreeRTOS.org - Documentation, training, latest information,
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55 license and contact details.
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57 http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
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58 including FreeRTOS+Trace - an indispensable productivity tool.
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60 Real Time Engineers ltd license FreeRTOS to High Integrity Systems, who sell
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61 the code with commercial support, indemnification, and middleware, under
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62 the OpenRTOS brand: http://www.OpenRTOS.com. High Integrity Systems also
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63 provide a safety engineered and independently SIL3 certified version under
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64 the SafeRTOS brand: http://www.SafeRTOS.com.
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68 * This demo application file demonstrates the use of queues to pass data
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69 * between co-routines.
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71 * N represents the number of 'fixed delay' co-routines that are created and
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72 * is set during initialisation.
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74 * N 'fixed delay' co-routines are created that just block for a fixed
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75 * period then post the number of an LED onto a queue. Each such co-routine
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76 * uses a different block period. A single 'flash' co-routine is also created
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77 * that blocks on the same queue, waiting for the number of the next LED it
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78 * should flash. Upon receiving a number it simply toggle the instructed LED
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79 * then blocks on the queue once more. In this manner each LED from LED 0 to
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80 * LED N-1 is caused to flash at a different rate.
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82 * The 'fixed delay' co-routines are created with co-routine priority 0. The
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83 * flash co-routine is created with co-routine priority 1. This means that
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84 * the queue should never contain more than a single item. This is because
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85 * posting to the queue will unblock the 'flash' co-routine, and as this has
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86 * a priority greater than the tasks posting to the queue it is guaranteed to
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87 * have emptied the queue and blocked once again before the queue can contain
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88 * any more date. An error is indicated if an attempt to post data to the
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89 * queue fails - indicating that the queue is already full.
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93 /* Scheduler includes. */
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94 #include "FreeRTOS.h"
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95 #include "croutine.h"
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98 /* Demo application includes. */
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99 #include "partest.h"
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100 #include "crflash.h"
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102 /* The queue should only need to be of length 1. See the description at the
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103 top of the file. */
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104 #define crfQUEUE_LENGTH 1
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106 #define crfFIXED_DELAY_PRIORITY 0
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107 #define crfFLASH_PRIORITY 1
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109 /* Only one flash co-routine is created so the index is not significant. */
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110 #define crfFLASH_INDEX 0
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112 /* Don't allow more than crfMAX_FLASH_TASKS 'fixed delay' co-routines to be
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114 #define crfMAX_FLASH_TASKS 8
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116 /* We don't want to block when posting to the queue. */
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117 #define crfPOSTING_BLOCK_TIME 0
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120 * The 'fixed delay' co-routine as described at the top of the file.
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122 static void prvFixedDelayCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );
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125 * The 'flash' co-routine as described at the top of the file.
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127 static void prvFlashCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex );
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129 /* The queue used to pass data between the 'fixed delay' co-routines and the
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130 'flash' co-routine. */
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131 static xQueueHandle xFlashQueue;
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133 /* This will be set to pdFALSE if we detect an error. */
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134 static portBASE_TYPE xCoRoutineFlashStatus = pdPASS;
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136 /*-----------------------------------------------------------*/
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139 * See the header file for details.
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141 void vStartFlashCoRoutines( unsigned portBASE_TYPE uxNumberToCreate )
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143 unsigned portBASE_TYPE uxIndex;
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145 if( uxNumberToCreate > crfMAX_FLASH_TASKS )
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147 uxNumberToCreate = crfMAX_FLASH_TASKS;
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150 /* Create the queue used to pass data between the co-routines. */
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151 xFlashQueue = xQueueCreate( crfQUEUE_LENGTH, sizeof( unsigned portBASE_TYPE ) );
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155 /* Create uxNumberToCreate 'fixed delay' co-routines. */
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156 for( uxIndex = 0; uxIndex < uxNumberToCreate; uxIndex++ )
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158 xCoRoutineCreate( prvFixedDelayCoRoutine, crfFIXED_DELAY_PRIORITY, uxIndex );
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161 /* Create the 'flash' co-routine. */
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162 xCoRoutineCreate( prvFlashCoRoutine, crfFLASH_PRIORITY, crfFLASH_INDEX );
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165 /*-----------------------------------------------------------*/
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167 static void prvFixedDelayCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
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169 /* Even though this is a co-routine the xResult variable does not need to be
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170 static as we do not need it to maintain its state between blocks. */
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171 signed portBASE_TYPE xResult;
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172 /* The uxIndex parameter of the co-routine function is used as an index into
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173 the xFlashRates array to obtain the delay period to use. */
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174 static const portTickType xFlashRates[ crfMAX_FLASH_TASKS ] = { 150 / portTICK_RATE_MS,
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175 200 / portTICK_RATE_MS,
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176 250 / portTICK_RATE_MS,
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177 300 / portTICK_RATE_MS,
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178 350 / portTICK_RATE_MS,
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179 400 / portTICK_RATE_MS,
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180 450 / portTICK_RATE_MS,
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181 500 / portTICK_RATE_MS };
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183 /* Co-routines MUST start with a call to crSTART. */
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184 crSTART( xHandle );
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188 /* Post our uxIndex value onto the queue. This is used as the LED to
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190 crQUEUE_SEND( xHandle, xFlashQueue, ( void * ) &uxIndex, crfPOSTING_BLOCK_TIME, &xResult );
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192 if( xResult != pdPASS )
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194 /* For the reasons stated at the top of the file we should always
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195 find that we can post to the queue. If we could not then an error
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197 xCoRoutineFlashStatus = pdFAIL;
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200 crDELAY( xHandle, xFlashRates[ uxIndex ] );
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203 /* Co-routines MUST end with a call to crEND. */
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206 /*-----------------------------------------------------------*/
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208 static void prvFlashCoRoutine( xCoRoutineHandle xHandle, unsigned portBASE_TYPE uxIndex )
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210 /* Even though this is a co-routine the variable do not need to be
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211 static as we do not need it to maintain their state between blocks. */
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212 signed portBASE_TYPE xResult;
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213 unsigned portBASE_TYPE uxLEDToFlash;
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215 /* Co-routines MUST start with a call to crSTART. */
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216 crSTART( xHandle );
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221 /* Block to wait for the number of the LED to flash. */
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222 crQUEUE_RECEIVE( xHandle, xFlashQueue, &uxLEDToFlash, portMAX_DELAY, &xResult );
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224 if( xResult != pdPASS )
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226 /* We would not expect to wake unless we received something. */
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227 xCoRoutineFlashStatus = pdFAIL;
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231 /* We received the number of an LED to flash - flash it! */
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232 vParTestToggleLED( uxLEDToFlash );
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236 /* Co-routines MUST end with a call to crEND. */
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239 /*-----------------------------------------------------------*/
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241 portBASE_TYPE xAreFlashCoRoutinesStillRunning( void )
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243 /* Return pdPASS or pdFAIL depending on whether an error has been detected
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245 return xCoRoutineFlashStatus;
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