Use of Queue with timeout for not receiving data Revision as of 12:07, 30 May 2015 by Amruta (Talk | contribs) (diff) ← Older revision | Latest revision (diff) | Newer revision → (diff)

Amruta (talk)

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Intro

Check RTOS Basics : Queue tutorial for API details.

Code

For more examples check this.

	/***************************************************************************************************
	ExploreEmbedded
	****************************************************************************************************
	* File: main.c (FreeRTOS)
	* Version: 15.0
	* Author: ExploreEmbedded
	* Website: http://www.exploreembedded.com/wiki
	* Description: Program to demonstrate the usage of queue to send and receive data between two tasks.
	Queue timeout for not receiving the data within specified amount of time
	The libraries have been tested on ExploreEmbedded development boards. We strongly believe that the
	library works on any of development boards for respective controllers. However, ExploreEmbedded
	disclaims any kind of hardware failure resulting out of usage of libraries, directly or indirectly.
	Files may be subject to change without prior notice. The revision history contains the information
	related to updates.
	GNU GENERAL PUBLIC LICENSE:
	This program is free software: you can redistribute it and/or modify
	it under the terms of the GNU General Public License as published by
	the Free Software Foundation, either version 3 of the License, or
	(at your option) any later version.
	This program 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
	along with this program. If not, see <http://www.gnu.org/licenses/>.
	Errors and omissions should be reported to codelibraries@exploreembedded.com
	**************************************************************************************************/
	/* Scheduler include files. */
	#include "FreeRtOSConfig.h"
	#include "FreeRTOS.h"
	#include "task.h"
	#include "croutine.h"
	#include "queue.h"
	#include "uart.h" // Explore Embedded UART library
	#define MaxQueueSize 3
	#define MaxElementsPerQueue 20
	static void MyTask1(void* pvParameters);
	static void MyTask2(void* pvParameters);
	xTaskHandle TaskHandle_1;
	xTaskHandle TaskHandle_2;
	xQueueHandle MyQueueHandleId;
	#define LED_Task1 0x02u
	#define LED_Task2 0x04u
	#define LED_PORT LPC_GPIO2->FIOPIN
	int main(void)
	{
	SystemInit(); /* Initialize the controller */
	UART_Init(38400); /* Initialize the Uart module */
	LPC_GPIO2->FIODIR = 0xffffffffu;
	MyQueueHandleId = xQueueCreate(MaxQueueSize,MaxElementsPerQueue); /* Cretae a queue */
	if(MyQueueHandleId != 0)
	{
	UART_Printf("\n\rQueue Created");
	xTaskCreate( MyTask1, ( signed char * )"Task1", configMINIMAL_STACK_SIZE, NULL, 3, &TaskHandle_1 );
	xTaskCreate( MyTask2, ( signed char * )"Task2", configMINIMAL_STACK_SIZE, NULL, 2, &TaskHandle_2 );
	vTaskStartScheduler(); /* start the scheduler */
	}
	else
	UART_Printf("\n\rQueue not Created");
	while(1);
	return 0;
	}
	static void MyTask1(void* pvParameters)
	{
	char RxBuffer[MaxElementsPerQueue];
	LED_PORT = LED_Task1; /* Led to indicate the execution of Task1*/
	UART_Printf("\n\rTask1, Reading the data from queue");
	if(pdTRUE == xQueueReceive(MyQueueHandleId,RxBuffer,100))
	{
	LED_PORT = LED_Task1; /* Led to indicate the execution of Task1*/
	UART_Printf("\n\rBack in task1, Received data is:%s",RxBuffer);
	}
	else
	{
	LED_PORT = LED_Task1; /* Led to indicate the execution of Task1*/
	UART_Printf("\n\rBack in task1, No Data received:");
	}
	vTaskDelete(TaskHandle_1);
	}
	static void MyTask2(void* pvParameters)
	{
	char TxBuffer[MaxElementsPerQueue]={"Hello world"};
	LED_PORT = LED_Task2; /* Led to indicate the execution of Task2*/
	UART_Printf("\n\rTask2, Waiting for some time");
	vTaskDelay(200);
	LED_PORT = LED_Task2; /* Led to indicate the execution of Task2*/
	UART_Printf("\n\rTask2, Filling the data onto queue");
	if(pdTRUE == xQueueSend(MyQueueHandleId,TxBuffer,100))
	{
	LED_PORT = LED_Task2; /* Led to indicate the execution of Task2*/
	UART_Printf("\n\rSuccessfully sent the data");
	}
	else
	{
	LED_PORT = LED_Task2; /* Led to indicate the execution of Task2*/
	UART_Printf("\n\rSending Failed");
	}
	UART_Printf("\n\rExiting task2");
	vTaskDelete(TaskHandle_2);
	}

view raw queue2.c hosted with ❤ by GitHub

Output

Waveform

Waveform