/* | |
* FreeRTOS Kernel V10.0.1 | |
* Copyright (C) 2017 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 ); | |
} | |
} | |