/* | |
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. | |
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*/ | |
/****************************************************************************** | |
* NOTE 1: The Win32 port is a simulation (or is that emulation?) only! Do not | |
* expect to get real time behaviour from the Win32 port or this demo | |
* application. It is provided as a convenient development and demonstration | |
* test bed only. This was tested using Windows XP on a dual core laptop. | |
* | |
* Windows will not be running the FreeRTOS simulator threads continuously, so | |
* the timing information in the FreeRTOS+Trace logs have no meaningful units. | |
* See the documentation page for the Windows simulator for an explanation of | |
* the slow timing: | |
* http://www.freertos.org/FreeRTOS-Windows-Simulator-Emulator-for-Visual-Studio-and-Eclipse-MingW.html | |
* - READ THE WEB DOCUMENTATION FOR THIS PORT FOR MORE INFORMATION ON USING IT - | |
* | |
* NOTE 2: This project provides two demo applications. A simple blinky style | |
* project, and a more comprehensive test and demo application. The | |
* mainCREATE_SIMPLE_BLINKY_DEMO_ONLY setting in main.c is used to select | |
* between the two. See the notes on using mainCREATE_SIMPLE_BLINKY_DEMO_ONLY | |
* in main.c. This file implements the simply blinky style version. | |
* | |
* NOTE 3: This file only contains the source code that is specific to the | |
* basic demo. Generic functions, such FreeRTOS hook functions, are defined | |
* in main.c. | |
****************************************************************************** | |
* | |
* main_blinky() creates one queue, and two tasks. It then starts the | |
* scheduler. | |
* | |
* The Queue Send Task: | |
* The queue send task is implemented by the prvQueueSendTask() function in | |
* this file. prvQueueSendTask() sits in a loop that causes it to repeatedly | |
* block for 200 (simulated as far as the scheduler is concerned, but in | |
* reality much longer - see notes above) milliseconds, before sending the | |
* value 100 to the queue that was created within main_blinky(). Once the | |
* value is sent, the task loops back around to block for another 200 | |
* (simulated) milliseconds. | |
* | |
* The Queue Receive Task: | |
* The queue receive task is implemented by the prvQueueReceiveTask() function | |
* in this file. prvQueueReceiveTask() sits in a loop where it repeatedly | |
* blocks on attempts to read data from the queue that was created within | |
* main_blinky(). When data is received, the task checks the value of the | |
* data, and if the value equals the expected 100, outputs a message. The | |
* 'block time' parameter passed to the queue receive function specifies that | |
* the task should be held in the Blocked state indefinitely to wait for data | |
* to be available on the queue. The queue receive task will only leave the | |
* Blocked state when the queue send task writes to the queue. As the queue | |
* send task writes to the queue every 200 (simulated - see notes above) | |
* milliseconds, the queue receive task leaves the Blocked state every 200 | |
* milliseconds, and therefore outputs a message every 200 milliseconds. | |
*/ | |
/* Standard includes. */ | |
#include <stdio.h> | |
/* Kernel includes. */ | |
#include "FreeRTOS.h" | |
#include "task.h" | |
#include "semphr.h" | |
/* Priorities at which the tasks are created. */ | |
#define mainQUEUE_RECEIVE_TASK_PRIORITY ( tskIDLE_PRIORITY + 2 ) | |
#define mainQUEUE_SEND_TASK_PRIORITY ( tskIDLE_PRIORITY + 1 ) | |
/* The rate at which data is sent to the queue. The 200ms value is converted | |
to ticks using the portTICK_PERIOD_MS constant. */ | |
#define mainQUEUE_SEND_FREQUENCY_MS ( 200 / portTICK_PERIOD_MS ) | |
/* The number of items the queue can hold. This is 1 as the receive task | |
will remove items as they are added, meaning the send task should always find | |
the queue empty. */ | |
#define mainQUEUE_LENGTH ( 1 ) | |
/* Values passed to the two tasks just to check the task parameter | |
functionality. */ | |
#define mainQUEUE_SEND_PARAMETER ( 0x1111UL ) | |
#define mainQUEUE_RECEIVE_PARAMETER ( 0x22UL ) | |
/*-----------------------------------------------------------*/ | |
/* | |
* The tasks as described in the comments at the top of this file. | |
*/ | |
static void prvQueueReceiveTask( void *pvParameters ); | |
static void prvQueueSendTask( void *pvParameters ); | |
/*-----------------------------------------------------------*/ | |
/* The queue used by both tasks. */ | |
static QueueHandle_t xQueue = NULL; | |
/*-----------------------------------------------------------*/ | |
void main_blinky( void ) | |
{ | |
/* Create the queue. */ | |
xQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( unsigned long ) ); | |
if( xQueue != NULL ) | |
{ | |
/* Start the two tasks as described in the comments at the top of this | |
file. */ | |
xTaskCreate( prvQueueReceiveTask, /* The function that implements the task. */ | |
"Rx", /* The text name assigned to the task - for debug only as it is not used by the kernel. */ | |
configMINIMAL_STACK_SIZE, /* The size of the stack to allocate to the task. */ | |
( void * ) mainQUEUE_RECEIVE_PARAMETER, /* The parameter passed to the task - just to check the functionality. */ | |
mainQUEUE_RECEIVE_TASK_PRIORITY, /* The priority assigned to the task. */ | |
NULL ); /* The task handle is not required, so NULL is passed. */ | |
xTaskCreate( prvQueueSendTask, "TX", configMINIMAL_STACK_SIZE, ( void * ) mainQUEUE_SEND_PARAMETER, mainQUEUE_SEND_TASK_PRIORITY, NULL ); | |
/* Start the tasks and timer running. */ | |
vTaskStartScheduler(); | |
} | |
/* If all is well, the scheduler will now be running, and the following | |
line will never be reached. If the following line does execute, then | |
there was insufficient FreeRTOS heap memory available for the idle and/or | |
timer tasks to be created. See the memory management section on the | |
FreeRTOS web site for more details. */ | |
for( ;; ); | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvQueueSendTask( void *pvParameters ) | |
{ | |
TickType_t xNextWakeTime; | |
const unsigned long ulValueToSend = 100UL; | |
/* Remove compiler warning in the case that configASSERT() is not | |
defined. */ | |
( void ) pvParameters; | |
/* Check the task parameter is as expected. */ | |
configASSERT( ( ( unsigned long ) pvParameters ) == mainQUEUE_SEND_PARAMETER ); | |
/* Initialise xNextWakeTime - this only needs to be done once. */ | |
xNextWakeTime = xTaskGetTickCount(); | |
for( ;; ) | |
{ | |
/* Place this task in the blocked state until it is time to run again. | |
The block time is specified in ticks, the constant used converts ticks | |
to ms. While in the Blocked state this task will not consume any CPU | |
time. */ | |
vTaskDelayUntil( &xNextWakeTime, mainQUEUE_SEND_FREQUENCY_MS ); | |
/* Send to the queue - causing the queue receive task to unblock and | |
toggle the LED. 0 is used as the block time so the sending operation | |
will not block - it shouldn't need to block as the queue should always | |
be empty at this point in the code. */ | |
xQueueSend( xQueue, &ulValueToSend, 0U ); | |
} | |
} | |
/*-----------------------------------------------------------*/ | |
static void prvQueueReceiveTask( void *pvParameters ) | |
{ | |
unsigned long ulReceivedValue; | |
/* Remove compiler warning in the case that configASSERT() is not | |
defined. */ | |
( void ) pvParameters; | |
/* Check the task parameter is as expected. */ | |
configASSERT( ( ( unsigned long ) pvParameters ) == mainQUEUE_RECEIVE_PARAMETER ); | |
for( ;; ) | |
{ | |
/* Wait until something arrives in the queue - this task will block | |
indefinitely provided INCLUDE_vTaskSuspend is set to 1 in | |
FreeRTOSConfig.h. */ | |
xQueueReceive( xQueue, &ulReceivedValue, portMAX_DELAY ); | |
/* To get here something must have been received from the queue, but | |
is it the expected value? If it is, toggle the LED. */ | |
if( ulReceivedValue == 100UL ) | |
{ | |
/* Normally calling printf() from a task is not a good idea. Here | |
there is lots of stack space and only one task is using console IO | |
so it is ok. */ | |
printf( "Message received\r\n" ); | |
fflush( stdout ); | |
ulReceivedValue = 0U; | |
} | |
} | |
} | |
/*-----------------------------------------------------------*/ | |