/* | |
FreeRTOS V6.0.4 - Copyright (C) 2010 Real Time Engineers Ltd. | |
*************************************************************************** | |
* * | |
* If you are: * | |
* * | |
* + New to FreeRTOS, * | |
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* * | |
* "Using the FreeRTOS Real Time Kernel - a Practical Guide" * | |
* http://www.FreeRTOS.org/Documentation * | |
* * | |
* A pdf reference manual is also available. Both are usually delivered * | |
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*************************************************************************** | |
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 exception 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. | |
*/ | |
/** | |
* This version of flash .c is for use on systems that have limited stack space | |
* and no display facilities. The complete version can be found in the | |
* Demo/Common/Full directory. | |
* | |
* Three tasks are created, each of which flash an LED at a different rate. The first | |
* LED flashes every 200ms, the second every 400ms, the third every 600ms. | |
* | |
* The LED flash tasks provide instant visual feedback. They show that the scheduler | |
* is still operational. | |
* | |
*/ | |
#include <stdlib.h> | |
/* Scheduler include files. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
/* Demo program include files. */ | |
#include "partest.h" | |
#include "flash.h" | |
#define ledSTACK_SIZE configMINIMAL_STACK_SIZE | |
#define ledNUMBER_OF_LEDS ( 3 ) | |
#define ledFLASH_RATE_BASE ( ( portTickType ) 333 ) | |
/* Variable used by the created tasks to calculate the LED number to use, and | |
the rate at which they should flash the LED. */ | |
static volatile unsigned portBASE_TYPE uxFlashTaskNumber = 0; | |
/* The task that is created three times. */ | |
static portTASK_FUNCTION_PROTO( vLEDFlashTask, pvParameters ); | |
/*-----------------------------------------------------------*/ | |
void vStartLEDFlashTasks( unsigned portBASE_TYPE uxPriority ) | |
{ | |
signed portBASE_TYPE xLEDTask; | |
/* Create the three tasks. */ | |
for( xLEDTask = 0; xLEDTask < ledNUMBER_OF_LEDS; ++xLEDTask ) | |
{ | |
/* Spawn the task. */ | |
xTaskCreate( vLEDFlashTask, ( signed char * ) "LEDx", ledSTACK_SIZE, NULL, uxPriority, ( xTaskHandle * ) NULL ); | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
static portTASK_FUNCTION( vLEDFlashTask, pvParameters ) | |
{ | |
portTickType xFlashRate, xLastFlashTime; | |
unsigned portBASE_TYPE uxLED; | |
/* The parameters are not used. */ | |
( void ) pvParameters; | |
/* Calculate the LED and flash rate. */ | |
portENTER_CRITICAL(); | |
{ | |
/* See which of the eight LED's we should use. */ | |
uxLED = uxFlashTaskNumber; | |
/* Update so the next task uses the next LED. */ | |
uxFlashTaskNumber++; | |
} | |
portEXIT_CRITICAL(); | |
xFlashRate = ledFLASH_RATE_BASE + ( ledFLASH_RATE_BASE * ( portTickType ) uxLED ); | |
xFlashRate /= portTICK_RATE_MS; | |
/* We will turn the LED on and off again in the delay period, so each | |
delay is only half the total period. */ | |
xFlashRate /= ( portTickType ) 2; | |
/* We need to initialise xLastFlashTime prior to the first call to | |
vTaskDelayUntil(). */ | |
xLastFlashTime = xTaskGetTickCount(); | |
for(;;) | |
{ | |
/* Delay for half the flash period then turn the LED on. */ | |
vTaskDelayUntil( &xLastFlashTime, xFlashRate ); | |
vParTestToggleLED( uxLED ); | |
/* Delay for half the flash period then turn the LED off. */ | |
vTaskDelayUntil( &xLastFlashTime, xFlashRate ); | |
vParTestToggleLED( uxLED ); | |
} | |
} /*lint !e715 !e818 !e830 Function definition must be standard for task creation. */ | |