/* | |
FreeRTOS.org V5.3.0 - Copyright (C) 2003-2009 Richard Barry. | |
This file is part of the FreeRTOS.org distribution. | |
FreeRTOS.org 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.org without being obliged to provide | |
the source code for any proprietary components. Alternative commercial | |
license and support terms are also available upon request. See the | |
licensing section of http://www.FreeRTOS.org for full details. | |
FreeRTOS.org 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.org; if not, write to the Free Software Foundation, Inc., 59 | |
Temple Place, Suite 330, Boston, MA 02111-1307 USA. | |
*************************************************************************** | |
* * | |
* Get the FreeRTOS eBook! See http://www.FreeRTOS.org/Documentation * | |
* * | |
* This is a concise, step by step, 'hands on' guide that describes both * | |
* general multitasking concepts and FreeRTOS specifics. It presents and * | |
* explains numerous examples that are written using the FreeRTOS API. * | |
* Full source code for all the examples is provided in an accompanying * | |
* .zip file. * | |
* * | |
*************************************************************************** | |
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. | |
*/ | |
/* 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 lcdSHORT_DELAY 3 | |
/* SFR that seems to be missing from the standard header files. */ | |
#define PMAEN *( ( unsigned short * ) 0x60c ) | |
/* LCD commands. */ | |
#define lcdDEFAULT_FUNCTION 0x3c | |
#define lcdDISPLAY_CONTROL 0x0c | |
#define lcdCLEAR_DISPLAY 0x01 | |
#define lcdENTRY_MODE 0x06 | |
/* 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; | |
/*-----------------------------------------------------------*/ | |
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 ) | |
{ | |
PMADDR = 0x0000; | |
PMDIN1 = 0x02; | |
} | |
else | |
{ | |
PMADDR = 0x0000; | |
PMDIN1 = 0xc0; | |
} | |
vTaskDelay( lcdSHORT_DELAY ); | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvLCDPutString( portCHAR *pcString ) | |
{ | |
/* Write out each character with appropriate delay between each. */ | |
while( *pcString ) | |
{ | |
PMADDR = 0x0001; | |
PMDIN1 = *pcString; | |
pcString++; | |
vTaskDelay( lcdSHORT_DELAY ); | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvLCDClear( void ) | |
{ | |
/* Clear the display. */ | |
PMADDR = 0x0000; | |
PMDIN1 = lcdCLEAR_DISPLAY; | |
vTaskDelay( lcdSHORT_DELAY ); | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvSetupLCD( void ) | |
{ | |
/* Setup the PMP. */ | |
PMCON = 0x83BF; | |
PMMODE = 0x3FF; | |
PMAEN = 1; | |
PMADDR = 0x0000; | |
vTaskDelay( lcdSHORT_DELAY ); | |
/* Set the default function. */ | |
PMDIN1 = lcdDEFAULT_FUNCTION; | |
vTaskDelay( lcdSHORT_DELAY ); | |
/* Set the display control. */ | |
PMDIN1 = lcdDISPLAY_CONTROL; | |
vTaskDelay( lcdSHORT_DELAY ); | |
/* Clear the display. */ | |
PMDIN1 = lcdCLEAR_DISPLAY; | |
vTaskDelay( lcdSHORT_DELAY ); | |
/* Set the entry mode. */ | |
PMDIN1 = lcdENTRY_MODE; | |
vTaskDelay( lcdSHORT_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 ); | |
} | |
} | |