X-Git-Url: https://git.sur5r.net/?p=freertos;a=blobdiff_plain;f=FreeRTOS%2FDemo%2FPosix_GCC%2Fsrc%2Fmain_blinky.c;fp=FreeRTOS%2FDemo%2FPosix_GCC%2Fsrc%2Fmain_blinky.c;h=69c7e7e2372f9f47510b47c445b853728f0c2872;hp=0000000000000000000000000000000000000000;hb=584c29e09cf7a95184b0e32718e8f711b781ffea;hpb=c5efd011e8c638d413ac395419119a451a0cb169 diff --git a/FreeRTOS/Demo/Posix_GCC/src/main_blinky.c b/FreeRTOS/Demo/Posix_GCC/src/main_blinky.c new file mode 100644 index 000000000..69c7e7e23 --- /dev/null +++ b/FreeRTOS/Demo/Posix_GCC/src/main_blinky.c @@ -0,0 +1,265 @@ +/* + * FreeRTOS Kernel V10.3.0 + * Copyright (C) 2020 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! + */ + +/****************************************************************************** + * NOTE 1: Windows will not be running the FreeRTOS demo threads continuously, so + * do not expect to get real time behaviour from the FreeRTOS Windows port, or + * this demo application. Also, the timing information in the FreeRTOS+Trace + * logs have no meaningful units. See the documentation page for the Windows + * port for further information: + * http://www.freertos.org/FreeRTOS-Windows-Simulator-Emulator-for-Visual-Studio-and-Eclipse-MingW.html + * + * 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 version. Console output + * is used in place of the normal LED toggling. + * + * 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, one software timer, 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. It uses vTaskDelayUntil() to create a periodic task that sends + * the value 100 to the queue every 200 milliseconds (please read the notes + * above regarding the accuracy of timing under Windows). + * + * The Queue Send Software Timer: + * The timer is an auto-reload timer with a period of two seconds. The timer's + * callback function writes the value 200 to the queue. The callback function + * is implemented by prvQueueSendTimerCallback() within this file. + * + * The Queue Receive Task: + * The queue receive task is implemented by the prvQueueReceiveTask() function + * in this file. prvQueueReceiveTask() waits for data to arrive on the queue. + * When data is received, the task checks the value of the data, then outputs a + * message to indicate if the data came from the queue send task or the queue + * send software timer. + * + * Expected Behaviour: + * - The queue send task writes to the queue every 200ms, so every 200ms the + * queue receive task will output a message indicating that data was received + * on the queue from the queue send task. + * - The queue send software timer has a period of two seconds, and is reset + * each time a key is pressed. So if two seconds expire without a key being + * pressed then the queue receive task will output a message indicating that + * data was received on the queue from the queue send software timer. + * + * NOTE: Console input and output relies on Windows system calls, which can + * interfere with the execution of the FreeRTOS Windows port. This demo only + * uses Windows system call occasionally. Heavier use of Windows system calls + * can crash the port. + */ + +#include +#include + +/* Kernel includes. */ +#include "FreeRTOS.h" +#include "task.h" +#include "timers.h" +#include "semphr.h" + +/* Local includes. */ +#include "console.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 times are converted from +milliseconds to ticks using the pdMS_TO_TICKS() macro. */ +#define mainTASK_SEND_FREQUENCY_MS pdMS_TO_TICKS( 200UL ) +#define mainTIMER_SEND_FREQUENCY_MS pdMS_TO_TICKS( 2000UL ) + +/* The number of items the queue can hold at once. */ +#define mainQUEUE_LENGTH ( 2 ) + +/* The values sent to the queue receive task from the queue send task and the +queue send software timer respectively. */ +#define mainVALUE_SENT_FROM_TASK ( 100UL ) +#define mainVALUE_SENT_FROM_TIMER ( 200UL ) + +/*-----------------------------------------------------------*/ + +/* + * The tasks as described in the comments at the top of this file. + */ +static void prvQueueReceiveTask( void *pvParameters ); +static void prvQueueSendTask( void *pvParameters ); + +/* + * The callback function executed when the software timer expires. + */ +static void prvQueueSendTimerCallback( TimerHandle_t xTimerHandle ); + +/*-----------------------------------------------------------*/ + +/* The queue used by both tasks. */ +static QueueHandle_t xQueue = NULL; + +/* A software timer that is started from the tick hook. */ +static TimerHandle_t xTimer = NULL; + +/*-----------------------------------------------------------*/ + +/*** SEE THE COMMENTS AT THE TOP OF THIS FILE ***/ +void main_blinky( void ) +{ +const TickType_t xTimerPeriod = mainTIMER_SEND_FREQUENCY_MS; + + /* Create the queue. */ + xQueue = xQueueCreate( mainQUEUE_LENGTH, sizeof( uint32_t ) ); + + 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. */ + NULL, /* The parameter passed to the task - not used in this simple case. */ + 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, NULL, mainQUEUE_SEND_TASK_PRIORITY, NULL ); + + /* Create the software timer, but don't start it yet. */ + xTimer = xTimerCreate( "Timer", /* The text name assigned to the software timer - for debug only as it is not used by the kernel. */ + xTimerPeriod, /* The period of the software timer in ticks. */ + pdTRUE, /* xAutoReload is set to pdTRUE. */ + NULL, /* The timer's ID is not used. */ + prvQueueSendTimerCallback );/* The function executed when the timer expires. */ + + if( xTimer != NULL ) + { + xTimerStart( xTimer, 0 ); + } + + /* 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 TickType_t xBlockTime = mainTASK_SEND_FREQUENCY_MS; +const uint32_t ulValueToSend = mainVALUE_SENT_FROM_TASK; + + /* Prevent the compiler warning about the unused parameter. */ + ( void ) pvParameters; + + /* 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, pdMS_TO_TICKS() was used to + convert a time specified in milliseconds into a time specified in ticks. + While in the Blocked state this task will not consume any CPU time. */ + vTaskDelayUntil( &xNextWakeTime, xBlockTime ); + + /* Send to the queue - causing the queue receive task to unblock and + write to the console. 0 is used as the block time so the send operation + will not block - it shouldn't need to block as the queue should always + have at least one space at this point in the code. */ + xQueueSend( xQueue, &ulValueToSend, 0U ); + } +} +/*-----------------------------------------------------------*/ + +static void prvQueueSendTimerCallback( TimerHandle_t xTimerHandle ) +{ +const uint32_t ulValueToSend = mainVALUE_SENT_FROM_TIMER; + + /* This is the software timer callback function. The software timer has a + period of two seconds and is reset each time a key is pressed. This + callback function will execute if the timer expires, which will only happen + if a key is not pressed for two seconds. */ + + /* Avoid compiler warnings resulting from the unused parameter. */ + ( void ) xTimerHandle; + + /* Send to the queue - causing the queue receive task to unblock and + write out a message. This function is called from the timer/daemon task, so + must not block. Hence the block time is set to 0. */ + xQueueSend( xQueue, &ulValueToSend, 0U ); +} +/*-----------------------------------------------------------*/ + +static void prvQueueReceiveTask( void *pvParameters ) +{ +uint32_t ulReceivedValue; + + /* Prevent the compiler warning about the unused parameter. */ + ( void ) pvParameters; + + for( ;; ) + { + /* Wait until something arrives in the queue - this task will block + indefinitely provided INCLUDE_vTaskSuspend is set to 1 in + FreeRTOSConfig.h. It will not use any CPU time while it is in the + Blocked state. */ + xQueueReceive( xQueue, &ulReceivedValue, portMAX_DELAY ); + + /* To get here something must have been received from the queue, but + is it an expected value? 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. However, note the comments at the top of + this file about the risks of making Windows system calls (such as + console output) from a FreeRTOS task. */ + if( ulReceivedValue == mainVALUE_SENT_FROM_TASK ) + { + console_print( "Message received from task\n" ); + } + else if( ulReceivedValue == mainVALUE_SENT_FROM_TIMER ) + { + console_print( "Message received from software timer\n" ); + } + else + { + console_print( "Unexpected message\n" ); + } + } +} +/*-----------------------------------------------------------*/