/* | |
FreeRTOS V7.1.0 - Copyright (C) 2011 Real Time Engineers Ltd. | |
*************************************************************************** | |
* * | |
* FreeRTOS tutorial books are available in pdf and paperback. * | |
* Complete, revised, and edited pdf reference manuals are also * | |
* available. * | |
* * | |
* Purchasing FreeRTOS documentation will not only help you, by * | |
* ensuring you get running as quickly as possible and with an * | |
* in-depth knowledge of how to use FreeRTOS, it will also help * | |
* the FreeRTOS project to continue with its mission of providing * | |
* professional grade, cross platform, de facto standard solutions * | |
* for microcontrollers - completely free of charge! * | |
* * | |
* >>> See http://www.FreeRTOS.org/Documentation for details. <<< * | |
* * | |
* Thank you for using FreeRTOS, and thank you for your support! * | |
* * | |
*************************************************************************** | |
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. See the GNU General Public License for | |
more details. You should have received a copy of the GNU General Public | |
License and the FreeRTOS license exception along with FreeRTOS; if not it | |
can be viewed here: http://www.freertos.org/a00114.html and also obtained | |
by writing to Richard Barry, contact details for whom are available on the | |
FreeRTOS WEB site. | |
1 tab == 4 spaces! | |
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. | |
*/ | |
/*----------------------------------------------------------- | |
* 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 xQueueHandle 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, ( signed char * ) "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 ); | |
} | |
} | |
} | |
/*-----------------------------------------------------------*/ | |