2 FreeRTOS V7.1.1 - 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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67 /*-----------------------------------------------------------
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68 * Normally, a demo application would define ParTest (parallel port test)
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69 * functions to write to an LED. In this case, four '*' symbols that are
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70 * output to the debug printf() port are used to simulate LED outputs.
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71 *-----------------------------------------------------------*/
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73 /* Standard includes. */
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77 /* Library includes. */
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78 #include "lpc43xx_i2c.h"
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80 /* Kernel includes. */
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81 #include "FreeRTOS.h"
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85 /* Standard demo include. */
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86 #include "partest.h"
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88 /* The number of LED outputs. */
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89 #define partstMAX_LEDS 4
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91 /* Commands written to the PCA9502. */
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92 #define partstIO_WRITE_COMMAND ( ( unsigned char ) ( 0x0BU << 3U ) )
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93 #define partstIO_DIR_COMMAND ( ( unsigned char ) ( 0x0AU << 3U ) )
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94 #define partstSLAVE_ADDRESS ( ( unsigned char ) ( 0x9AU >> 1U ) )
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96 /* Just defines the length of the queue used to pass toggle commands to the I2C
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98 #define partstLED_COMMAND_QUEUE_LENGTH ( 6 )
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99 /*-----------------------------------------------------------*/
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102 * The LEDs are connected to an I2C port expander. Therefore, writing to an
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103 * LED takes longer than might be expected if the LED was connected directly
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104 * to a GPIO pin. As several tasks, and a timer, toggle LEDs, it is convenient
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105 * to use a gatekeeper task to ensure access is both mutually exclusive and
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106 * serialised. Tasks other than this gatekeeper task must not access the I2C
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109 static void prvI2CGateKeeperTask( void *pvParameters );
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111 /* The queue used to communicate toggle commands with the I2C gatekeeper
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113 static xQueueHandle xI2CCommandQueue = NULL;
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114 /*-----------------------------------------------------------*/
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116 void vParTestInitialise( void )
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118 unsigned char ucBuffer[ 2 ];
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119 I2C_M_SETUP_Type xI2CMessage;
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121 /* The LEDs are on an I2C IO expander. Initialise the I2C interface. */
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122 I2C_Init( LPC_I2C0, 300000 );
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123 I2C_Cmd( LPC_I2C0, ENABLE );
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125 /* GPIO0-GPIO2 to output. */
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126 ucBuffer[ 0 ] = partstIO_DIR_COMMAND;
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127 ucBuffer[ 1 ] = 0x0f;
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128 xI2CMessage.sl_addr7bit = partstSLAVE_ADDRESS;
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129 xI2CMessage.tx_data = ucBuffer ;
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130 xI2CMessage.tx_length = sizeof( ucBuffer );
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131 xI2CMessage.rx_data = NULL;
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132 xI2CMessage.rx_length = 0;
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133 xI2CMessage.retransmissions_max = 3;
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134 I2C_MasterTransferData( LPC_I2C0, &xI2CMessage, I2C_TRANSFER_POLLING );
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136 /* Create the mutex used to guard access to the I2C bus. */
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137 xI2CCommandQueue = xQueueCreate( partstLED_COMMAND_QUEUE_LENGTH, sizeof( unsigned char ) );
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138 configASSERT( xI2CCommandQueue );
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140 /* Create the I2C gatekeeper task itself. */
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141 xTaskCreate( prvI2CGateKeeperTask, ( signed char * ) "I2C", configMINIMAL_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, NULL );
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143 /*-----------------------------------------------------------*/
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145 void vParTestToggleLED( unsigned long ulLED )
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147 unsigned char ucLED = ( unsigned char ) ulLED;
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149 /* Only the gatekeeper task will actually access the I2C port, so send the
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150 toggle request to the gatekeeper task. A block time of zero is used as
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151 this function is called by a software timer callback. */
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152 xQueueSend( xI2CCommandQueue, &ucLED, 0UL );
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154 /*-----------------------------------------------------------*/
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156 static void prvI2CGateKeeperTask( void *pvParameters )
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158 unsigned char ucBuffer[ 2 ], ucLED;
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159 static unsigned char ucLEDState = 0xffU;
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160 static I2C_M_SETUP_Type xI2CMessage; /* Static so it is not on the stack as this is called from task code. */
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162 /* Just to remove compiler warnings. */
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163 ( void ) pvParameters;
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167 /* Wait for the next command. */
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168 xQueueReceive( xI2CCommandQueue, &ucLED, portMAX_DELAY );
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170 /* Only this task is allowed to touch the I2C port, so there is no need
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171 for additional mutual exclusion. */
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172 if( ucLED < partstMAX_LEDS )
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174 /* Which bit is being manipulated? */
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175 ucLED = 0x01 << ucLED;
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177 /* Is the bit currently set or clear? */
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178 if( ( ucLEDState & ucLED ) == 0U )
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180 ucLEDState |= ucLED;
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184 ucLEDState &= ~ucLED;
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187 ucBuffer[ 0 ] = partstIO_WRITE_COMMAND;
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188 ucBuffer[ 1 ] = ucLEDState;
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190 xI2CMessage.sl_addr7bit = partstSLAVE_ADDRESS;
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191 xI2CMessage.tx_data = ucBuffer ;
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192 xI2CMessage.tx_length = sizeof( ucBuffer );
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193 xI2CMessage.rx_data = NULL;
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194 xI2CMessage.rx_length = 0;
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195 xI2CMessage.retransmissions_max = 3;
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196 I2C_MasterTransferData( LPC_I2C0, &xI2CMessage, I2C_TRANSFER_POLLING );
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200 /*-----------------------------------------------------------*/
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