229 lines
8.2 KiB
C
229 lines
8.2 KiB
C
/*
|
|
* FreeRTOS V202212.00
|
|
* 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.
|
|
*
|
|
* https://www.FreeRTOS.org
|
|
* https://github.com/FreeRTOS
|
|
*
|
|
*/
|
|
|
|
/*
|
|
* A simple example that shows a stream buffer being used to pass data from an
|
|
* interrupt to a task.
|
|
*
|
|
* There are two strings, pcStringToSend and pcStringToReceive, where
|
|
* pcStringToReceive is a substring of pcStringToSend. The interrupt sends
|
|
* a few bytes of pcStringToSend to a stream buffer ever few times that it
|
|
* executes. A task reads the bytes from the stream buffer, looking for the
|
|
* substring, and flagging an error if the received data is invalid.
|
|
*/
|
|
|
|
/* Standard includes. */
|
|
#include "stdio.h"
|
|
#include "string.h"
|
|
|
|
/* FreeRTOS includes. */
|
|
#include "FreeRTOS.h"
|
|
#include "task.h"
|
|
#include "stream_buffer.h"
|
|
|
|
/* Demo app includes. */
|
|
#include "StreamBufferInterrupt.h"
|
|
|
|
#define sbiSTREAM_BUFFER_LENGTH_BYTES ( ( size_t ) 100 )
|
|
#define sbiSTREAM_BUFFER_TRIGGER_LEVEL_10 ( ( BaseType_t ) 10 )
|
|
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/* Implements the task that receives a stream of bytes from the interrupt. */
|
|
static void prvReceivingTask( void * pvParameters );
|
|
|
|
/*-----------------------------------------------------------*/
|
|
|
|
/* The stream buffer that is used to send data from an interrupt to the task. */
|
|
static StreamBufferHandle_t xStreamBuffer = NULL;
|
|
|
|
/* The string that is sent from the interrupt to the task four bytes at a
|
|
* time. Must be multiple of 4 bytes long as the ISR sends 4 bytes at a time*/
|
|
static const char * pcStringToSend = "_____Hello FreeRTOS_____";
|
|
|
|
/* The string to task is looking for, which must be a substring of
|
|
* pcStringToSend. */
|
|
static const char * pcStringToReceive = "Hello FreeRTOS";
|
|
|
|
/* Set to pdFAIL if anything unexpected happens. */
|
|
static BaseType_t xDemoStatus = pdPASS;
|
|
|
|
/* Incremented each time pcStringToReceive is correctly received, provided no
|
|
* errors have occurred. Used so the check task can check this task is still
|
|
* running as expected. */
|
|
static uint32_t ulCycleCount = 0;
|
|
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vStartStreamBufferInterruptDemo( void )
|
|
{
|
|
/* Create the stream buffer that sends data from the interrupt to the
|
|
* task, and create the task. */
|
|
xStreamBuffer = xStreamBufferCreate( /* The buffer length in bytes. */
|
|
sbiSTREAM_BUFFER_LENGTH_BYTES,
|
|
/* The stream buffer's trigger level. */
|
|
sbiSTREAM_BUFFER_TRIGGER_LEVEL_10 );
|
|
|
|
xTaskCreate( prvReceivingTask, /* The function that implements the task. */
|
|
"StrIntRx", /* Human readable name for the task. */
|
|
configMINIMAL_STACK_SIZE, /* Stack size (in words!). */
|
|
NULL, /* Task parameter is not used. */
|
|
tskIDLE_PRIORITY + 2, /* The priority at which the task is created. */
|
|
NULL ); /* No use for the task handle. */
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
static void prvReceivingTask( void * pvParameters )
|
|
{
|
|
char cRxBuffer[ 20 ];
|
|
BaseType_t xNextByte = 0;
|
|
|
|
/* Remove warning about unused parameters. */
|
|
( void ) pvParameters;
|
|
|
|
/* Make sure the string will fit in the Rx buffer, including the NULL
|
|
* terminator. */
|
|
configASSERT( sizeof( cRxBuffer ) > strlen( pcStringToReceive ) );
|
|
|
|
/* Make sure the stream buffer has been created. */
|
|
configASSERT( xStreamBuffer != NULL );
|
|
|
|
/* Start with the Rx buffer in a known state. */
|
|
memset( cRxBuffer, 0x00, sizeof( cRxBuffer ) );
|
|
|
|
for( ; ; )
|
|
{
|
|
/* Keep receiving characters until the end of the string is received.
|
|
* Note: An infinite block time is used to simplify the example. Infinite
|
|
* block times are not recommended in production code as they do not allow
|
|
* for error recovery. */
|
|
xStreamBufferReceive( /* The stream buffer data is being received from. */
|
|
xStreamBuffer,
|
|
/* Where to place received data. */
|
|
( void * ) &( cRxBuffer[ xNextByte ] ),
|
|
/* The number of bytes to receive. */
|
|
sizeof( char ),
|
|
|
|
/* The time to wait for the next data if the buffer
|
|
* is empty. */
|
|
portMAX_DELAY );
|
|
|
|
/* If xNextByte is 0 then this task is looking for the start of the
|
|
* string, which is 'H'. */
|
|
if( xNextByte == 0 )
|
|
{
|
|
if( cRxBuffer[ xNextByte ] == 'H' )
|
|
{
|
|
/* The start of the string has been found. Now receive
|
|
* characters until the end of the string is found. */
|
|
xNextByte++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Receiving characters while looking for the end of the string,
|
|
* which is an 'S'. */
|
|
if( cRxBuffer[ xNextByte ] == 'S' )
|
|
{
|
|
/* The string has now been received. Check its validity. */
|
|
if( strcmp( cRxBuffer, pcStringToReceive ) != 0 )
|
|
{
|
|
xDemoStatus = pdFAIL;
|
|
}
|
|
|
|
/* Return to start looking for the beginning of the string
|
|
* again. */
|
|
memset( cRxBuffer, 0x00, sizeof( cRxBuffer ) );
|
|
xNextByte = 0;
|
|
|
|
/* Increment the cycle count as an indication to the check task
|
|
* that this demo is still running. */
|
|
if( xDemoStatus == pdPASS )
|
|
{
|
|
ulCycleCount++;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
/* Receive the next character the next time around, while
|
|
* continuing to look for the end of the string. */
|
|
xNextByte++;
|
|
|
|
configASSERT( ( size_t ) xNextByte < sizeof( cRxBuffer ) );
|
|
}
|
|
}
|
|
}
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
void vBasicStreamBufferSendFromISR( void )
|
|
{
|
|
static size_t xNextByteToSend = 0;
|
|
const BaseType_t xCallsBetweenSends = 100, xBytesToSend = 4;
|
|
static BaseType_t xCallCount = 0;
|
|
|
|
/* Is it time to write to the stream buffer again? */
|
|
xCallCount++;
|
|
|
|
if( xCallCount > xCallsBetweenSends )
|
|
{
|
|
xCallCount = 0;
|
|
|
|
/* Send the next four bytes to the stream buffer. */
|
|
xStreamBufferSendFromISR( xStreamBuffer,
|
|
( const void * ) ( pcStringToSend + xNextByteToSend ),
|
|
xBytesToSend,
|
|
NULL );
|
|
|
|
/* Send the next four bytes the next time around, wrapping to the start
|
|
* of the string if necessary. */
|
|
xNextByteToSend += xBytesToSend;
|
|
|
|
if( xNextByteToSend >= strlen( pcStringToSend ) )
|
|
{
|
|
xNextByteToSend = 0;
|
|
}
|
|
}
|
|
}
|
|
/*-----------------------------------------------------------*/
|
|
|
|
BaseType_t xIsInterruptStreamBufferDemoStillRunning( void )
|
|
{
|
|
uint32_t ulLastCycleCount = 0;
|
|
|
|
/* Check the demo is still running. */
|
|
if( ulLastCycleCount == ulCycleCount )
|
|
{
|
|
xDemoStatus = pdFAIL;
|
|
}
|
|
else
|
|
{
|
|
ulLastCycleCount = ulCycleCount;
|
|
}
|
|
|
|
return xDemoStatus;
|
|
}
|