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/*
* FreeRTOS Kernel V10.2.1
* Copyright (C) 2019 Amazon.com, Inc. or its affiliates. All Rights Reserved.
*
* Permission is hereby granted, free of charge, to any person obtaining a copy of
* this software and associated documentation files (the "Software"), to deal in
* the Software without restriction, including without limitation the rights to
* use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of
* the Software, and to permit persons to whom the Software is furnished to do so,
* subject to the following conditions:
*
* The above copyright notice and this permission notice shall be included in all
* copies or substantial portions of the Software.
*
* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
* IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS
* FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR
* COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER
* IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN
* CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
*
* http://www.FreeRTOS.org
* http://aws.amazon.com/freertos
*
* 1 tab == 4 spaces!
*/
/* 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 short usRow );
/*
* Write a string of text to the LCD.
*/
static void prvLCDPutString( char *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 ( 8 / portTICK_PERIOD_MS )
#define lcdLONG_DELAY ( 15 / portTICK_PERIOD_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. */
QueueHandle_t xLCDQueue;
/* LCD access functions. */
static void prvLCDCommand( char cCommand );
static void prvLCDData( char cChar );
/*-----------------------------------------------------------*/
QueueHandle_t 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, "LCD", configMINIMAL_STACK_SIZE, NULL, tskIDLE_PRIORITY + 1, NULL );
return xLCDQueue;
}
/*-----------------------------------------------------------*/
static void prvLCDGotoRow( unsigned short usRow )
{
if(usRow == 0)
{
prvLCDCommand( LCD_CURSOR_HOME_CMD );
}
else
{
prvLCDCommand( LCD_NEW_LINE );
}
}
/*-----------------------------------------------------------*/
static void prvLCDCommand( char cCommand )
{
PMPSetAddress( LCD_COMMAND_ADDRESS );
PMPMasterWrite( cCommand );
vTaskDelay( lcdSHORT_DELAY );
}
/*-----------------------------------------------------------*/
static void prvLCDData( char cChar )
{
PMPSetAddress( LCD_DATA_ADDRESS );
PMPMasterWrite( cChar );
vTaskDelay( lcdVERY_SHORT_DELAY );
}
/*-----------------------------------------------------------*/
static void prvLCDPutString( char *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 short 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 );
}
}
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