FreeRTOS-Plus/Demo/Common/FreeRTOS_Plus_CLI_Demos/UARTCommandConsole.c

/*
    FreeRTOS V8.2.2 - Copyright (C) 2015 Real Time Engineers Ltd.
    All rights reserved

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    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     !<<
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    >>!   obliged to provide the source code for proprietary components     !<<
    >>!   outside of the FreeRTOS kernel.                                   !<<
    ***************************************************************************

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    WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
    FOR A PARTICULAR PURPOSE.  Full license text is available on the following
    link: http://www.freertos.org/a00114.html

    ***************************************************************************
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*/

/*
 * NOTE:  This file uses a third party USB CDC driver.
 */

/* Standard includes. */
#include "string.h"
#include "stdio.h"

/* FreeRTOS includes. */
#include "FreeRTOS.h"
#include "task.h"
#include "semphr.h"

/* Example includes. */
#include "FreeRTOS_CLI.h"

/* Demo application includes. */
#include "serial.h"

/* Dimensions the buffer into which input characters are placed. */
#define cmdMAX_INPUT_SIZE		50

/* Dimentions a buffer to be used by the UART driver, if the UART driver uses a
buffer at all. */
#define cmdQUEUE_LENGTH			25

/* DEL acts as a backspace. */
#define cmdASCII_DEL		( 0x7F )

/* The maximum time to wait for the mutex that guards the UART to become
available. */
#define cmdMAX_MUTEX_WAIT		pdMS_TO_TICKS( 300 )

#ifndef configCLI_BAUD_RATE
	#define configCLI_BAUD_RATE	115200
#endif

/*-----------------------------------------------------------*/

/*
 * The task that implements the command console processing.
 */
static void prvUARTCommandConsoleTask( void *pvParameters );
void vUARTCommandConsoleStart( uint16_t usStackSize, UBaseType_t uxPriority );

/*-----------------------------------------------------------*/

/* Const messages output by the command console. */
static const char * const pcWelcomeMessage = "FreeRTOS command server.\r\nType Help to view a list of registered commands.\r\n\r\n>";
static const char * const pcEndOfOutputMessage = "\r\n[Press ENTER to execute the previous command again]\r\n>";
static const char * const pcNewLine = "\r\n";

/* Used to guard access to the UART in case messages are sent to the UART from
more than one task. */
static SemaphoreHandle_t xTxMutex = NULL;

/* The handle to the UART port, which is not used by all ports. */
static xComPortHandle xPort = 0;

/*-----------------------------------------------------------*/

void vUARTCommandConsoleStart( uint16_t usStackSize, UBaseType_t uxPriority )
{
	/* Create the semaphore used to access the UART Tx. */
	xTxMutex = xSemaphoreCreateMutex();
	configASSERT( xTxMutex );

	/* Create that task that handles the console itself. */
	xTaskCreate( 	prvUARTCommandConsoleTask,	/* The task that implements the command console. */
					"CLI",						/* Text name assigned to the task.  This is just to assist debugging.  The kernel does not use this name itself. */
					usStackSize,				/* The size of the stack allocated to the task. */
					NULL,						/* The parameter is not used, so NULL is passed. */
					uxPriority,					/* The priority allocated to the task. */
					NULL );						/* A handle is not required, so just pass NULL. */
}
/*-----------------------------------------------------------*/

static void prvUARTCommandConsoleTask( void *pvParameters )
{
signed char cRxedChar;
uint8_t ucInputIndex = 0;
char *pcOutputString;
static char cInputString[ cmdMAX_INPUT_SIZE ], cLastInputString[ cmdMAX_INPUT_SIZE ];
BaseType_t xReturned;
xComPortHandle xPort;

	( void ) pvParameters;

	/* Obtain the address of the output buffer.  Note there is no mutual
	exclusion on this buffer as it is assumed only one command console interface
	will be used at any one time. */
	pcOutputString = FreeRTOS_CLIGetOutputBuffer();

	/* Initialise the UART. */
	xPort = xSerialPortInitMinimal( configCLI_BAUD_RATE, cmdQUEUE_LENGTH );

	/* Send the welcome message. */
	vSerialPutString( xPort, ( signed char * ) pcWelcomeMessage, strlen( pcWelcomeMessage ) );

	for( ;; )
	{
		/* Wait for the next character.  The while loop is used in case
		INCLUDE_vTaskSuspend is not set to 1 - in which case portMAX_DELAY will
		be a genuine block time rather than an infinite block time. */
		while( xSerialGetChar( xPort, &cRxedChar, portMAX_DELAY ) != pdPASS );

		/* Ensure exclusive access to the UART Tx. */
		if( xSemaphoreTake( xTxMutex, cmdMAX_MUTEX_WAIT ) == pdPASS )
		{
			/* Echo the character back. */
			xSerialPutChar( xPort, cRxedChar, portMAX_DELAY );

			/* Was it the end of the line? */
			if( cRxedChar == '\n' || cRxedChar == '\r' )
			{
				/* Just to space the output from the input. */
				vSerialPutString( xPort, ( signed char * ) pcNewLine, strlen( pcNewLine ) );

				/* See if the command is empty, indicating that the last command
				is to be executed again. */
				if( ucInputIndex == 0 )
				{
					/* Copy the last command back into the input string. */
					strcpy( cInputString, cLastInputString );
				}

				/* Pass the received command to the command interpreter.  The
				command interpreter is called repeatedly until it returns
				pdFALSE	(indicating there is no more output) as it might
				generate more than one string. */
				do
				{
					/* Get the next output string from the command interpreter. */
					xReturned = FreeRTOS_CLIProcessCommand( cInputString, pcOutputString, configCOMMAND_INT_MAX_OUTPUT_SIZE );

					/* Write the generated string to the UART. */
					vSerialPutString( xPort, ( signed char * ) pcOutputString, strlen( pcOutputString ) );

				} while( xReturned != pdFALSE );

				/* All the strings generated by the input command have been
				sent.  Clear the input string ready to receive the next command.
				Remember the command that was just processed first in case it is
				to be processed again. */
				strcpy( cLastInputString, cInputString );
				ucInputIndex = 0;
				memset( cInputString, 0x00, cmdMAX_INPUT_SIZE );

				vSerialPutString( xPort, ( signed char * ) pcEndOfOutputMessage, strlen( pcEndOfOutputMessage ) );
			}
			else
			{
				if( cRxedChar == '\r' )
				{
					/* Ignore the character. */
				}
				else if( ( cRxedChar == '\b' ) || ( cRxedChar == cmdASCII_DEL ) )
				{
					/* Backspace was pressed.  Erase the last character in the
					string - if any. */
					if( ucInputIndex > 0 )
					{
						ucInputIndex--;
						cInputString[ ucInputIndex ] = '\0';
					}
				}
				else
				{
					/* A character was entered.  Add it to the string entered so
					far.  When a \n is entered the complete	string will be
					passed to the command interpreter. */
					if( ( cRxedChar >= ' ' ) && ( cRxedChar <= '~' ) )
					{
						if( ucInputIndex < cmdMAX_INPUT_SIZE )
						{
							cInputString[ ucInputIndex ] = cRxedChar;
							ucInputIndex++;
						}
					}
				}
			}

			/* Must ensure to give the mutex back. */
			xSemaphoreGive( xTxMutex );
		}
	}
}
/*-----------------------------------------------------------*/

void vOutputString( const char * const pcMessage )
{
	if( xSemaphoreTake( xTxMutex, cmdMAX_MUTEX_WAIT ) == pdPASS )
	{
		vSerialPutString( xPort, ( signed char * ) pcMessage, strlen( pcMessage ) );
		xSemaphoreGive( xTxMutex );
	}
}
/*-----------------------------------------------------------*/