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[/] [openrisc/] [trunk/] [rtos/] [freertos-6.1.1/] [Demo/] [PIC32MX_MPLAB/] [lcd.c] - Blame information for rev 614

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1 614 jeremybenn
/*
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    FreeRTOS V6.1.1 - Copyright (C) 2011 Real Time Engineers Ltd.
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    ***************************************************************************
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    *                                                                         *
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    * If you are:                                                             *
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    *                                                                         *
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    *    + New to FreeRTOS,                                                   *
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    *    + Wanting to learn FreeRTOS or multitasking in general quickly       *
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    *    + Looking for basic training,                                        *
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    *    + Wanting to improve your FreeRTOS skills and productivity           *
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    *                                                                         *
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    * then take a look at the FreeRTOS books - available as PDF or paperback  *
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    *                                                                         *
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    *        "Using the FreeRTOS Real Time Kernel - a Practical Guide"        *
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    *                  http://www.FreeRTOS.org/Documentation                  *
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    *                                                                         *
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    * A pdf reference manual is also available.  Both are usually delivered   *
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    * to your inbox within 20 minutes to two hours when purchased between 8am *
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    * and 8pm GMT (although please allow up to 24 hours in case of            *
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    * exceptional circumstances).  Thank you for your support!                *
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    *                                                                         *
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    ***************************************************************************
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    This file is part of the FreeRTOS distribution.
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    FreeRTOS is free software; you can redistribute it and/or modify it under
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    the terms of the GNU General Public License (version 2) as published by the
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    Free Software Foundation AND MODIFIED BY the FreeRTOS exception.
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    ***NOTE*** The exception to the GPL is included to allow you to distribute
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    a combined work that includes FreeRTOS without being obliged to provide the
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    source code for proprietary components outside of the FreeRTOS kernel.
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    FreeRTOS is distributed in the hope that it will be useful, but WITHOUT
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    ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
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    FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License for
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    more details. You should have received a copy of the GNU General Public
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    License and the FreeRTOS license exception along with FreeRTOS; if not it
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    can be viewed here: http://www.freertos.org/a00114.html and also obtained
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    by writing to Richard Barry, contact details for whom are available on the
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    FreeRTOS WEB site.
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    1 tab == 4 spaces!
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    http://www.FreeRTOS.org - Documentation, latest information, license and
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    contact details.
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    http://www.SafeRTOS.com - A version that is certified for use in safety
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    critical systems.
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    http://www.OpenRTOS.com - Commercial support, development, porting,
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    licensing and training services.
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*/
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/* peripheral library include */
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#include <plib.h>
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/* Scheduler includes. */
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#include "FreeRTOS.h"
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#include "task.h"
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#include "queue.h"
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/* Demo includes. */
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#include "lcd.h"
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/*
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 * The LCD is written to by more than one task so is controlled by this
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 * 'gatekeeper' task.  This is the only task that is actually permitted to
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 * access the LCD directly.  Other tasks wanting to display a message send
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 * the message to the gatekeeper.
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 */
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static void vLCDTask( void *pvParameters );
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/*
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 * Setup the peripherals required to communicate with the LCD.
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 */
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static void prvSetupLCD( void );
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/*
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 * Move to the first (0) or second (1) row of the LCD.
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 */
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static void prvLCDGotoRow( unsigned portSHORT usRow );
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/*
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 * Write a string of text to the LCD.
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 */
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static void prvLCDPutString( portCHAR *pcString );
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/*
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 * Clear the LCD.
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 */
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static void prvLCDClear( void );
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/*-----------------------------------------------------------*/
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/* Brief delay to permit the LCD to catch up with commands. */
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#define lcdVERY_SHORT_DELAY     ( 1 )
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#define lcdSHORT_DELAY          ( 4 / portTICK_RATE_MS )
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#define lcdLONG_DELAY           ( 15 / portTICK_RATE_MS )
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/* LCD specific definitions. */
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#define LCD_CLEAR_DISPLAY_CMD                   0x01
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#define LCD_CURSOR_HOME_CMD                             0x02
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#define LCD_ENTRY_MODE_CMD                              0x04
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#define LCD_ENTRY_MODE_INCREASE                 0x02
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#define LCD_DISPLAY_CTRL_CMD                    0x08
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#define LCD_DISPLAY_CTRL_DISPLAY_ON             0x04
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#define LCD_FUNCTION_SET_CMD                    0x20
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#define LCD_FUNCTION_SET_8_BITS                 0x10
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#define LCD_FUNCTION_SET_2_LINES                0x08
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#define LCD_FUNCTION_SET_LRG_FONT               0x04
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#define LCD_NEW_LINE                                    0xC0
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#define LCD_COMMAND_ADDRESS                             0x00
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#define LCD_DATA_ADDRESS                                0x01
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/* The length of the queue used to send messages to the LCD gatekeeper task. */
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#define lcdQUEUE_SIZE           3
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/*-----------------------------------------------------------*/
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/* The queue used to send messages to the LCD task. */
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xQueueHandle xLCDQueue;
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/* LCD access functions. */
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static void prvLCDCommand( portCHAR cCommand );
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static void prvLCDData( portCHAR cChar );
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/*-----------------------------------------------------------*/
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xQueueHandle xStartLCDTask( void )
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{
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        /* Create the queue used by the LCD task.  Messages for display on the LCD
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        are received via this queue. */
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        xLCDQueue = xQueueCreate( lcdQUEUE_SIZE, sizeof( xLCDMessage ));
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        /* Start the task that will write to the LCD.  The LCD hardware is
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        initialised from within the task itself so delays can be used. */
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        xTaskCreate( vLCDTask, ( signed portCHAR * ) "LCD", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL );
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        return xLCDQueue;
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}
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/*-----------------------------------------------------------*/
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static void prvLCDGotoRow( unsigned portSHORT usRow )
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{
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        if(usRow == 0)
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        {
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                prvLCDCommand( LCD_CURSOR_HOME_CMD );
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        }
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        else
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        {
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                prvLCDCommand( LCD_NEW_LINE );
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        }
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}
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/*-----------------------------------------------------------*/
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static void prvLCDCommand( portCHAR cCommand )
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{
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        PMPSetAddress( LCD_COMMAND_ADDRESS );
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        PMPMasterWrite( cCommand );
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        vTaskDelay( lcdSHORT_DELAY );
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}
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/*-----------------------------------------------------------*/
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static void prvLCDData( portCHAR cChar )
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{
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        PMPSetAddress( LCD_DATA_ADDRESS );
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        PMPMasterWrite( cChar );
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        vTaskDelay( lcdVERY_SHORT_DELAY );
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}
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/*-----------------------------------------------------------*/
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static void prvLCDPutString( portCHAR *pcString )
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{
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        /* Write out each character with appropriate delay between each. */
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        while(*pcString)
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        {
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                prvLCDData(*pcString);
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                pcString++;
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                vTaskDelay(lcdSHORT_DELAY);
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        }
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}
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/*-----------------------------------------------------------*/
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static void prvLCDClear(void)
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{
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        prvLCDCommand(LCD_CLEAR_DISPLAY_CMD);
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}
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/*-----------------------------------------------------------*/
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static void prvSetupLCD(void)
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{
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        /* Wait for proper power up. */
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        vTaskDelay( lcdLONG_DELAY );
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        /* Open the PMP port */
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        mPMPOpen((PMP_ON | PMP_READ_WRITE_EN | PMP_CS2_CS1_EN |
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                          PMP_LATCH_POL_HI | PMP_CS2_POL_HI | PMP_CS1_POL_HI |
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                          PMP_WRITE_POL_HI | PMP_READ_POL_HI),
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                         (PMP_MODE_MASTER1 | PMP_WAIT_BEG_4 | PMP_WAIT_MID_15 |
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                          PMP_WAIT_END_4),
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                          PMP_PEN_0, 0);
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        /* Wait for the LCD to power up correctly. */
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        vTaskDelay( lcdLONG_DELAY );
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        vTaskDelay( lcdLONG_DELAY );
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        vTaskDelay( lcdLONG_DELAY );
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        /* Set up the LCD function. */
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        prvLCDCommand( LCD_FUNCTION_SET_CMD | LCD_FUNCTION_SET_8_BITS | LCD_FUNCTION_SET_2_LINES | LCD_FUNCTION_SET_LRG_FONT );
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        /* Turn the display on. */
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        prvLCDCommand( LCD_DISPLAY_CTRL_CMD | LCD_DISPLAY_CTRL_DISPLAY_ON );
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        /* Clear the display. */
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        prvLCDCommand( LCD_CLEAR_DISPLAY_CMD );
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        vTaskDelay( lcdLONG_DELAY );
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        /* Increase the cursor. */
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        prvLCDCommand( LCD_ENTRY_MODE_CMD | LCD_ENTRY_MODE_INCREASE );
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        vTaskDelay( lcdLONG_DELAY );
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        vTaskDelay( lcdLONG_DELAY );
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        vTaskDelay( lcdLONG_DELAY );
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}
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/*-----------------------------------------------------------*/
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static void vLCDTask(void *pvParameters)
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{
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xLCDMessage xMessage;
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unsigned portSHORT usRow = 0;
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        /* Initialise the hardware.  This uses delays so must not be called prior
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        to the scheduler being started. */
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        prvSetupLCD();
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        /* Welcome message. */
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        prvLCDPutString( "www.FreeRTOS.org" );
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        for(;;)
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        {
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                /* Wait for a message to arrive that requires displaying. */
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                while( xQueueReceive( xLCDQueue, &xMessage, portMAX_DELAY ) != pdPASS );
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                /* Clear the current display value. */
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                prvLCDClear();
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                /* Switch rows each time so we can see that the display is still being
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                updated. */
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                prvLCDGotoRow( usRow & 0x01 );
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                usRow++;
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                prvLCDPutString( xMessage.pcMessage );
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                /* Delay the requested amount of time to ensure the text just written
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                to the LCD is not overwritten. */
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                vTaskDelay( xMessage.xMinDisplayTime );
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        }
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}
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