/* * FreeRTOS Kernel V10.2.1 * Copyright (C) 2019 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! */ /** * 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 /* 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. */