/* | |
* FreeRTOS Kernel V10.0.0 | |
* 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. If you wish to use our Amazon | |
* FreeRTOS name, please do so in a fair use way that does not cause confusion. | |
* | |
* 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! | |
*/ | |
/** | |
* 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 ( ( TickType_t ) 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 UBaseType_t uxFlashTaskNumber = 0; | |
/* The task that is created three times. */ | |
static portTASK_FUNCTION_PROTO( vLEDFlashTask, pvParameters ); | |
/*-----------------------------------------------------------*/ | |
void vStartLEDFlashTasks( UBaseType_t uxPriority ) | |
{ | |
BaseType_t xLEDTask; | |
/* Create the three tasks. */ | |
for( xLEDTask = 0; xLEDTask < ledNUMBER_OF_LEDS; ++xLEDTask ) | |
{ | |
/* Spawn the task. */ | |
xTaskCreate( vLEDFlashTask, "LEDx", ledSTACK_SIZE, NULL, uxPriority, ( TaskHandle_t * ) NULL ); | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
static portTASK_FUNCTION( vLEDFlashTask, pvParameters ) | |
{ | |
TickType_t xFlashRate, xLastFlashTime; | |
UBaseType_t 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 * ( TickType_t ) uxLED ); | |
xFlashRate /= portTICK_PERIOD_MS; | |
/* We will turn the LED on and off again in the delay period, so each | |
delay is only half the total period. */ | |
xFlashRate /= ( TickType_t ) 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. */ | |