/* | |
FreeRTOS V5.4.2 - Copyright (C) 2009 Real Time Engineers Ltd. | |
This file is part of the FreeRTOS distribution. | |
FreeRTOS is free software; you can redistribute it and/or modify it under | |
the terms of the GNU General Public License (version 2) as published by the | |
Free Software Foundation and modified by the FreeRTOS exception. | |
**NOTE** The exception to the GPL is included to allow you to distribute a | |
combined work that includes FreeRTOS without being obliged to provide the | |
source code for proprietary components outside of the FreeRTOS kernel. | |
Alternative commercial license and support terms are also available upon | |
request. See the licensing section of http://www.FreeRTOS.org for full | |
license details. | |
FreeRTOS 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; if not, write to the Free Software Foundation, Inc., 59 | |
Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
*************************************************************************** | |
* * | |
* Looking for a quick start? Then check out the FreeRTOS eBook! * | |
* See http://www.FreeRTOS.org/Documentation for details * | |
* * | |
*************************************************************************** | |
1 tab == 4 spaces! | |
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. | |
*/ | |
/* peripheral library include */ | |
#include <plib.h> | |
/* Scheduler includes. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
#include "queue.h" | |
/* Demo includes. */ | |
#include "lcd.h" | |
/* | |
* The LCD is written to by more than one task so is controlled by this | |
* 'gatekeeper' task. This is the only task that is actually permitted to | |
* access the LCD directly. Other tasks wanting to display a message send | |
* the message to the gatekeeper. | |
*/ | |
static void vLCDTask( void *pvParameters ); | |
/* | |
* Setup the peripherals required to communicate with the LCD. | |
*/ | |
static void prvSetupLCD( void ); | |
/* | |
* Move to the first (0) or second (1) row of the LCD. | |
*/ | |
static void prvLCDGotoRow( unsigned portSHORT usRow ); | |
/* | |
* Write a string of text to the LCD. | |
*/ | |
static void prvLCDPutString( portCHAR *pcString ); | |
/* | |
* Clear the LCD. | |
*/ | |
static void prvLCDClear( void ); | |
/*-----------------------------------------------------------*/ | |
/* Brief delay to permit the LCD to catch up with commands. */ | |
#define lcdVERY_SHORT_DELAY ( 1 ) | |
#define lcdSHORT_DELAY ( 4 / portTICK_RATE_MS ) | |
#define lcdLONG_DELAY ( 15 / portTICK_RATE_MS ) | |
/* LCD specific definitions. */ | |
#define LCD_CLEAR_DISPLAY_CMD 0x01 | |
#define LCD_CURSOR_HOME_CMD 0x02 | |
#define LCD_ENTRY_MODE_CMD 0x04 | |
#define LCD_ENTRY_MODE_INCREASE 0x02 | |
#define LCD_DISPLAY_CTRL_CMD 0x08 | |
#define LCD_DISPLAY_CTRL_DISPLAY_ON 0x04 | |
#define LCD_FUNCTION_SET_CMD 0x20 | |
#define LCD_FUNCTION_SET_8_BITS 0x10 | |
#define LCD_FUNCTION_SET_2_LINES 0x08 | |
#define LCD_FUNCTION_SET_LRG_FONT 0x04 | |
#define LCD_NEW_LINE 0xC0 | |
#define LCD_COMMAND_ADDRESS 0x00 | |
#define LCD_DATA_ADDRESS 0x01 | |
/* The length of the queue used to send messages to the LCD gatekeeper task. */ | |
#define lcdQUEUE_SIZE 3 | |
/*-----------------------------------------------------------*/ | |
/* The queue used to send messages to the LCD task. */ | |
xQueueHandle xLCDQueue; | |
/* LCD access functions. */ | |
static void prvLCDCommand( portCHAR cCommand ); | |
static void prvLCDData( portCHAR cChar ); | |
/*-----------------------------------------------------------*/ | |
xQueueHandle xStartLCDTask( void ) | |
{ | |
/* Create the queue used by the LCD task. Messages for display on the LCD | |
are received via this queue. */ | |
xLCDQueue = xQueueCreate( lcdQUEUE_SIZE, sizeof( xLCDMessage )); | |
/* Start the task that will write to the LCD. The LCD hardware is | |
initialised from within the task itself so delays can be used. */ | |
xTaskCreate( vLCDTask, ( signed portCHAR * ) "LCD", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL ); | |
return xLCDQueue; | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvLCDGotoRow( unsigned portSHORT usRow ) | |
{ | |
if(usRow == 0) | |
{ | |
prvLCDCommand( LCD_CURSOR_HOME_CMD ); | |
} | |
else | |
{ | |
prvLCDCommand( LCD_NEW_LINE ); | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvLCDCommand( portCHAR cCommand ) | |
{ | |
PMPSetAddress( LCD_COMMAND_ADDRESS ); | |
PMPMasterWrite( cCommand ); | |
vTaskDelay( lcdSHORT_DELAY ); | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvLCDData( portCHAR cChar ) | |
{ | |
PMPSetAddress( LCD_DATA_ADDRESS ); | |
PMPMasterWrite( cChar ); | |
vTaskDelay( lcdVERY_SHORT_DELAY ); | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvLCDPutString( portCHAR *pcString ) | |
{ | |
/* Write out each character with appropriate delay between each. */ | |
while(*pcString) | |
{ | |
prvLCDData(*pcString); | |
pcString++; | |
vTaskDelay(lcdSHORT_DELAY); | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvLCDClear(void) | |
{ | |
prvLCDCommand(LCD_CLEAR_DISPLAY_CMD); | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvSetupLCD(void) | |
{ | |
/* Wait for proper power up. */ | |
vTaskDelay( lcdLONG_DELAY ); | |
/* Open the PMP port */ | |
mPMPOpen((PMP_ON | PMP_READ_WRITE_EN | PMP_CS2_CS1_EN | | |
PMP_LATCH_POL_HI | PMP_CS2_POL_HI | PMP_CS1_POL_HI | | |
PMP_WRITE_POL_HI | PMP_READ_POL_HI), | |
(PMP_MODE_MASTER1 | PMP_WAIT_BEG_4 | PMP_WAIT_MID_15 | | |
PMP_WAIT_END_4), | |
PMP_PEN_0, 0); | |
/* Wait for the LCD to power up correctly. */ | |
vTaskDelay( lcdLONG_DELAY ); | |
vTaskDelay( lcdLONG_DELAY ); | |
vTaskDelay( lcdLONG_DELAY ); | |
/* Set up the LCD function. */ | |
prvLCDCommand( LCD_FUNCTION_SET_CMD | LCD_FUNCTION_SET_8_BITS | LCD_FUNCTION_SET_2_LINES | LCD_FUNCTION_SET_LRG_FONT ); | |
/* Turn the display on. */ | |
prvLCDCommand( LCD_DISPLAY_CTRL_CMD | LCD_DISPLAY_CTRL_DISPLAY_ON ); | |
/* Clear the display. */ | |
prvLCDCommand( LCD_CLEAR_DISPLAY_CMD ); | |
vTaskDelay( lcdLONG_DELAY ); | |
/* Increase the cursor. */ | |
prvLCDCommand( LCD_ENTRY_MODE_CMD | LCD_ENTRY_MODE_INCREASE ); | |
vTaskDelay( lcdLONG_DELAY ); | |
vTaskDelay( lcdLONG_DELAY ); | |
vTaskDelay( lcdLONG_DELAY ); | |
} | |
/*-----------------------------------------------------------*/ | |
static void vLCDTask(void *pvParameters) | |
{ | |
xLCDMessage xMessage; | |
unsigned portSHORT usRow = 0; | |
/* Initialise the hardware. This uses delays so must not be called prior | |
to the scheduler being started. */ | |
prvSetupLCD(); | |
/* Welcome message. */ | |
prvLCDPutString( "www.FreeRTOS.org" ); | |
for(;;) | |
{ | |
/* Wait for a message to arrive that requires displaying. */ | |
while( xQueueReceive( xLCDQueue, &xMessage, portMAX_DELAY ) != pdPASS ); | |
/* Clear the current display value. */ | |
prvLCDClear(); | |
/* Switch rows each time so we can see that the display is still being | |
updated. */ | |
prvLCDGotoRow( usRow & 0x01 ); | |
usRow++; | |
prvLCDPutString( xMessage.pcMessage ); | |
/* Delay the requested amount of time to ensure the text just written | |
to the LCD is not overwritten. */ | |
vTaskDelay( xMessage.xMinDisplayTime ); | |
} | |
} | |