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/*
FreeRTOS V8.0.1 - Copyright (C) 2014 Real Time Engineers Ltd.
All rights reserved
VISIT http://www.FreeRTOS.org TO ENSURE YOU ARE USING THE LATEST VERSION.
***************************************************************************
* *
* FreeRTOS provides completely free yet professionally developed, *
* robust, strictly quality controlled, supported, and cross *
* platform software that has become a de facto standard. *
* *
* Help yourself get started quickly and support the FreeRTOS *
* project by purchasing a FreeRTOS tutorial book, reference *
* manual, or both from: http://www.FreeRTOS.org/Documentation *
* *
* Thank you! *
* *
***************************************************************************
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 modification 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. !<<
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. Full license text is available from the following
link: http://www.freertos.org/a00114.html
1 tab == 4 spaces!
***************************************************************************
* *
* Having a problem? Start by reading the FAQ "My application does *
* not run, what could be wrong?" *
* *
* http://www.FreeRTOS.org/FAQHelp.html *
* *
***************************************************************************
http://www.FreeRTOS.org - Documentation, books, training, latest versions,
license and Real Time Engineers Ltd. contact details.
http://www.FreeRTOS.org/plus - A selection of FreeRTOS ecosystem products,
including FreeRTOS+Trace - an indispensable productivity tool, a DOS
compatible FAT file system, and our tiny thread aware UDP/IP stack.
http://www.OpenRTOS.com - Real Time Engineers ltd license FreeRTOS to High
Integrity Systems to sell under the OpenRTOS brand. Low cost OpenRTOS
licenses offer ticketed support, indemnification and middleware.
http://www.SafeRTOS.com - High Integrity Systems also provide a safety
engineered and independently SIL3 certified version for use in safety and
mission critical applications that require provable dependability.
1 tab == 4 spaces!
*/
/*-----------------------------------------------------------
* Normally, a demo application would define ParTest (parallel port test)
* functions to write to an LED. In this case, four '*' symbols that are
* output to the debug printf() port are used to simulate LED outputs.
*-----------------------------------------------------------*/
/* Standard includes. */
#include <stdio.h>
#include <string.h>
/* Library includes. */
#include "lpc43xx_i2c.h"
/* Kernel includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "queue.h"
/* Standard demo include. */
#include "partest.h"
/* The number of LED outputs. */
#define partstMAX_LEDS 4
/* Commands written to the PCA9502. */
#define partstIO_WRITE_COMMAND ( ( unsigned char ) ( 0x0BU << 3U ) )
#define partstIO_DIR_COMMAND ( ( unsigned char ) ( 0x0AU << 3U ) )
#define partstSLAVE_ADDRESS ( ( unsigned char ) ( 0x9AU >> 1U ) )
/* Just defines the length of the queue used to pass toggle commands to the I2C
gatekeeper task. */
#define partstLED_COMMAND_QUEUE_LENGTH ( 6 )
/*-----------------------------------------------------------*/
/*
* The LEDs are connected to an I2C port expander. Therefore, writing to an
* LED takes longer than might be expected if the LED was connected directly
* to a GPIO pin. As several tasks, and a timer, toggle LEDs, it is convenient
* to use a gatekeeper task to ensure access is both mutually exclusive and
* serialised. Tasks other than this gatekeeper task must not access the I2C
* port directly.
*/
static void prvI2CGateKeeperTask( void *pvParameters );
/* The queue used to communicate toggle commands with the I2C gatekeeper
task. */
static QueueHandle_t xI2CCommandQueue = NULL;
/*-----------------------------------------------------------*/
void vParTestInitialise( void )
{
unsigned char ucBuffer[ 2 ];
I2C_M_SETUP_Type xI2CMessage;
/* The LEDs are on an I2C IO expander. Initialise the I2C interface. */
I2C_Init( LPC_I2C0, 300000 );
I2C_Cmd( LPC_I2C0, ENABLE );
/* GPIO0-GPIO2 to output. */
ucBuffer[ 0 ] = partstIO_DIR_COMMAND;
ucBuffer[ 1 ] = 0x0f;
xI2CMessage.sl_addr7bit = partstSLAVE_ADDRESS;
xI2CMessage.tx_data = ucBuffer ;
xI2CMessage.tx_length = sizeof( ucBuffer );
xI2CMessage.rx_data = NULL;
xI2CMessage.rx_length = 0;
xI2CMessage.retransmissions_max = 3;
I2C_MasterTransferData( LPC_I2C0, &xI2CMessage, I2C_TRANSFER_POLLING );
/* Create the mutex used to guard access to the I2C bus. */
xI2CCommandQueue = xQueueCreate( partstLED_COMMAND_QUEUE_LENGTH, sizeof( unsigned char ) );
configASSERT( xI2CCommandQueue );
/* Create the I2C gatekeeper task itself. */
xTaskCreate( prvI2CGateKeeperTask, "I2C", configMINIMAL_STACK_SIZE, ( void * ) NULL, tskIDLE_PRIORITY, NULL );
}
/*-----------------------------------------------------------*/
void vParTestToggleLED( unsigned long ulLED )
{
unsigned char ucLED = ( unsigned char ) ulLED;
/* Only the gatekeeper task will actually access the I2C port, so send the
toggle request to the gatekeeper task. A block time of zero is used as
this function is called by a software timer callback. */
xQueueSend( xI2CCommandQueue, &ucLED, 0UL );
}
/*-----------------------------------------------------------*/
static void prvI2CGateKeeperTask( void *pvParameters )
{
unsigned char ucBuffer[ 2 ], ucLED;
static unsigned char ucLEDState = 0xffU;
static I2C_M_SETUP_Type xI2CMessage; /* Static so it is not on the stack as this is called from task code. */
/* Just to remove compiler warnings. */
( void ) pvParameters;
for( ;; )
{
/* Wait for the next command. */
xQueueReceive( xI2CCommandQueue, &ucLED, portMAX_DELAY );
/* Only this task is allowed to touch the I2C port, so there is no need
for additional mutual exclusion. */
if( ucLED < partstMAX_LEDS )
{
/* Which bit is being manipulated? */
ucLED = 0x01 << ucLED;
/* Is the bit currently set or clear? */
if( ( ucLEDState & ucLED ) == 0U )
{
ucLEDState |= ucLED;
}
else
{
ucLEDState &= ~ucLED;
}
ucBuffer[ 0 ] = partstIO_WRITE_COMMAND;
ucBuffer[ 1 ] = ucLEDState;
xI2CMessage.sl_addr7bit = partstSLAVE_ADDRESS;
xI2CMessage.tx_data = ucBuffer ;
xI2CMessage.tx_length = sizeof( ucBuffer );
xI2CMessage.rx_data = NULL;
xI2CMessage.rx_length = 0;
xI2CMessage.retransmissions_max = 3;
I2C_MasterTransferData( LPC_I2C0, &xI2CMessage, I2C_TRANSFER_POLLING );
}
}
}
/*-----------------------------------------------------------*/
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