You can not select more than 25 topics
Topics must start with a letter or number, can include dashes ('-') and can be up to 35 characters long.
92 lines
2.4 KiB
92 lines
2.4 KiB
/*
|
|
* Copyright (C) 2010,2012,2018 by Jonathan Naylor G4KLX
|
|
* Copyright (C) 2021-2022 by Geoffrey Merck F4FXL / KC3FRA
|
|
*
|
|
* 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 2 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, write to the Free Software
|
|
* Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
*/
|
|
|
|
|
|
#include <cstring>
|
|
#include <cassert>
|
|
#include <boost/algorithm/string.hpp>
|
|
|
|
#include "GPSACollector.h"
|
|
#include "StringUtils.h"
|
|
#include "Log.h"
|
|
#include "APRSUtils.h"
|
|
|
|
const unsigned int APRS_CSUM_LENGTH = 4U;
|
|
|
|
CGPSACollector::CGPSACollector() :
|
|
CSentenceCollector(SLOW_DATA_TYPE_GPS, "$$CRC", '\x0D')
|
|
{
|
|
|
|
}
|
|
|
|
bool CGPSACollector::isValidSentence(const std::string& sentence)
|
|
{
|
|
return isValidGPSA(sentence);
|
|
}
|
|
|
|
bool CGPSACollector::isValidGPSA(const std::string& gpsa)
|
|
{
|
|
if(gpsa.length() < 10U || !boost::starts_with(gpsa, "$$CRC"))
|
|
return false;
|
|
|
|
auto csum = CAPRSUtils::calcGPSAIcomCRC(gpsa);
|
|
auto csumStr = CStringUtils::string_format("%04X", csum);
|
|
auto expectedCsum = gpsa.substr(5U, APRS_CSUM_LENGTH);
|
|
bool res = ::strcasecmp(csumStr.c_str(), expectedCsum.c_str()) == 0;
|
|
return res;
|
|
}
|
|
|
|
unsigned int CGPSACollector::getDataInt(unsigned char * data, unsigned int length)
|
|
{
|
|
if(data == nullptr || length == 0U)
|
|
return 0U;
|
|
|
|
std::string aprsFrame;
|
|
|
|
if(!getDataInt(aprsFrame))
|
|
return 0U;
|
|
|
|
auto aprsFrameLen = aprsFrame.length();
|
|
|
|
if(length < aprsFrameLen) {
|
|
CLog::logDebug("Not enough space to copy GPS-A APRS frame");
|
|
return 0U;
|
|
}
|
|
|
|
for(unsigned int i = 0U; i < aprsFrameLen; i++){
|
|
data[i] = aprsFrame[i];
|
|
}
|
|
|
|
return aprsFrameLen;
|
|
}
|
|
|
|
bool CGPSACollector::getDataInt(std::string& data)
|
|
{
|
|
if(getSentence().empty())
|
|
return false;
|
|
|
|
data.clear();
|
|
auto aprsFrame = getSentence();
|
|
if(aprsFrame.length() < 11U)//do we have enough data beyond CRC?
|
|
return false;
|
|
|
|
data = aprsFrame.substr(10);
|
|
|
|
return true;
|
|
} |