mirror of
https://github.com/f4exb/sdrangel.git
synced 2024-11-03 15:31:15 -05:00
684 lines
23 KiB
C++
684 lines
23 KiB
C++
///////////////////////////////////////////////////////////////////////////////////
|
|
// Copyright (C) 2019 Edouard Griffiths, F4EXB //
|
|
// Copyright (C) 2020 Jon Beniston, M7RCE //
|
|
// //
|
|
// 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 as 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 V3 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/>. //
|
|
///////////////////////////////////////////////////////////////////////////////////
|
|
|
|
#include <cctype>
|
|
#include <QDebug>
|
|
|
|
#include "dsp/basebandsamplesink.h"
|
|
#include "dsp/datafifo.h"
|
|
#include "packetmodsource.h"
|
|
#include "util/crc.h"
|
|
#include "util/messagequeue.h"
|
|
#include "maincore.h"
|
|
#include "channel/channelapi.h"
|
|
|
|
PacketModSource::PacketModSource() :
|
|
m_channelSampleRate(48000),
|
|
m_channelFrequencyOffset(0),
|
|
m_spectrumRate(0),
|
|
m_audioPhase(0.0f),
|
|
m_fmPhase(0.0),
|
|
m_preemphasisFilter(48000, FMPREEMPHASIS_TAU_US),
|
|
m_spectrumSink(nullptr),
|
|
m_magsq(0.0),
|
|
m_levelCalcCount(0),
|
|
m_peakLevel(0.0f),
|
|
m_levelSum(0.0f),
|
|
m_state(idle),
|
|
m_byteIdx(0),
|
|
m_bitIdx(0),
|
|
m_last5Bits(0),
|
|
m_bitCount(0),
|
|
m_scrambler(0x10800, 0x0)
|
|
{
|
|
m_lowpass.create(301, m_channelSampleRate, 22000.0 / 2.0);
|
|
qDebug() << "PacketModSource::PacketModSource creating BPF : " << m_channelSampleRate;
|
|
m_bandpass.create(301, m_channelSampleRate, 800.0, 2600.0);
|
|
m_pulseShape.create(0.5, 6, m_channelSampleRate/9600);
|
|
|
|
m_demodBuffer.resize(1<<12);
|
|
m_demodBufferFill = 0;
|
|
|
|
applySettings(m_settings, true);
|
|
applyChannelSettings(m_channelSampleRate, m_channelFrequencyOffset, true);
|
|
}
|
|
|
|
PacketModSource::~PacketModSource()
|
|
{
|
|
}
|
|
|
|
void PacketModSource::pull(SampleVector::iterator begin, unsigned int nbSamples)
|
|
{
|
|
std::for_each(
|
|
begin,
|
|
begin + nbSamples,
|
|
[this](Sample& s) {
|
|
pullOne(s);
|
|
}
|
|
);
|
|
}
|
|
|
|
void PacketModSource::pullOne(Sample& sample)
|
|
{
|
|
if (m_settings.m_channelMute)
|
|
{
|
|
sample.m_real = 0.0f;
|
|
sample.m_imag = 0.0f;
|
|
return;
|
|
}
|
|
|
|
// Calculate next sample
|
|
modulateSample();
|
|
|
|
// Shift to carrier frequency
|
|
Complex ci = m_modSample;
|
|
ci *= m_carrierNco.nextIQ();
|
|
|
|
// Calculate power
|
|
double magsq = ci.real() * ci.real() + ci.imag() * ci.imag();
|
|
m_movingAverage(magsq);
|
|
m_magsq = m_movingAverage.asDouble();
|
|
|
|
// Convert from float to fixed point
|
|
sample.m_real = (FixReal) (ci.real() * SDR_TX_SCALEF);
|
|
sample.m_imag = (FixReal) (ci.imag() * SDR_TX_SCALEF);
|
|
}
|
|
|
|
void PacketModSource::sampleToSpectrum(Real sample)
|
|
{
|
|
if (m_spectrumSink)
|
|
{
|
|
Complex out;
|
|
Complex in;
|
|
in.real(sample);
|
|
in.imag(0.0f);
|
|
if (m_interpolator.decimate(&m_interpolatorDistanceRemain, in, &out))
|
|
{
|
|
sample = std::real(out);
|
|
m_sampleBuffer.push_back(Sample(sample * 0.891235351562f * SDR_TX_SCALEF, 0.0f));
|
|
m_spectrumSink->feed(m_sampleBuffer.begin(), m_sampleBuffer.end(), true);
|
|
m_sampleBuffer.clear();
|
|
m_interpolatorDistanceRemain += m_interpolatorDistance;
|
|
}
|
|
}
|
|
}
|
|
|
|
void PacketModSource::modulateSample()
|
|
{
|
|
Real audioMod;
|
|
Real linearRampGain;
|
|
|
|
if ((m_state == idle) || (m_state == wait))
|
|
{
|
|
audioMod = 0.0f;
|
|
m_modSample.real(audioMod);
|
|
m_modSample.imag(0);
|
|
calculateLevel(audioMod);
|
|
sampleToSpectrum(audioMod);
|
|
if (m_state == wait)
|
|
{
|
|
m_waitCounter--;
|
|
if (m_waitCounter == 0)
|
|
initTX();
|
|
}
|
|
}
|
|
else
|
|
{
|
|
|
|
if (m_sampleIdx == 0)
|
|
{
|
|
if (bitsValid())
|
|
{
|
|
// NRZI encoding - encode 0 as change of freq, 1 no change
|
|
if (getBit() == 0)
|
|
m_nrziBit = m_nrziBit == 1 ? 0 : 1;
|
|
// Scramble to ensure lots of transitions
|
|
if (m_settings.m_scramble)
|
|
m_scrambledBit = m_scrambler.scramble(m_nrziBit);
|
|
else
|
|
m_scrambledBit = m_nrziBit;
|
|
}
|
|
// Should we start ramping down power?
|
|
if ((m_bitCount < m_settings.m_rampDownBits) || ((m_bitCount == 0) && !m_settings.m_rampDownBits))
|
|
{
|
|
m_state = ramp_down;
|
|
if (m_settings.m_rampDownBits > 0)
|
|
m_powRamp = -m_settings.m_rampRange/(m_settings.m_rampDownBits * (Real)m_samplesPerSymbol);
|
|
}
|
|
}
|
|
m_sampleIdx++;
|
|
if (m_sampleIdx >= m_samplesPerSymbol)
|
|
m_sampleIdx = 0;
|
|
|
|
if (!m_settings.m_bbNoise)
|
|
{
|
|
if (m_settings.m_modulation == PacketModSettings::AFSK)
|
|
{
|
|
// Bell 202 AFSK
|
|
audioMod = sin(m_audioPhase);
|
|
if ((m_state == tx) || m_settings.m_modulateWhileRamping)
|
|
m_audioPhase += (M_PI * 2.0f * (m_scrambledBit ? m_settings.m_markFrequency : m_settings.m_spaceFrequency)) / (m_channelSampleRate);
|
|
if (m_audioPhase > M_PI)
|
|
m_audioPhase -= (2.0f * M_PI);
|
|
}
|
|
else
|
|
{
|
|
// FSK
|
|
if (m_settings.m_pulseShaping)
|
|
{
|
|
if ((m_sampleIdx == 1) && (m_state != ramp_down))
|
|
audioMod = m_pulseShape.filter(m_scrambledBit ? 1.0f : -1.0f);
|
|
else
|
|
audioMod = m_pulseShape.filter(0.0f);
|
|
}
|
|
else
|
|
audioMod = m_scrambledBit ? 1.0f : -1.0f;
|
|
}
|
|
}
|
|
else
|
|
audioMod = (Real)rand()/((Real)RAND_MAX)-0.5; // Noise to test filter frequency response
|
|
|
|
// Baseband bandpass filter
|
|
if (m_settings.m_bpf)
|
|
audioMod = m_bandpass.filter(audioMod);
|
|
|
|
// Preemphasis filter
|
|
if (m_settings.m_preEmphasis)
|
|
audioMod = m_preemphasisFilter.filter(audioMod);
|
|
|
|
if (m_audioFile.is_open())
|
|
m_audioFile << audioMod << "\n";
|
|
|
|
// Display baseband audio in spectrum analyser
|
|
sampleToSpectrum(audioMod);
|
|
|
|
// FM
|
|
m_fmPhase += m_phaseSensitivity * audioMod;
|
|
// Keep phase in range -pi,pi
|
|
if (m_fmPhase > M_PI)
|
|
m_fmPhase -= 2.0f * M_PI;
|
|
else if (m_fmPhase < -M_PI)
|
|
m_fmPhase += 2.0f * M_PI;
|
|
|
|
linearRampGain = powf(10.0f, m_pow/20.0f);
|
|
|
|
if (!m_settings.m_rfNoise)
|
|
{
|
|
m_modSample.real(m_linearGain * linearRampGain * cos(m_fmPhase));
|
|
m_modSample.imag(m_linearGain * linearRampGain * sin(m_fmPhase));
|
|
}
|
|
else
|
|
{
|
|
// Noise to test filter frequency response
|
|
m_modSample.real(m_linearGain * ((Real)rand()/((Real)RAND_MAX)-0.5f));
|
|
m_modSample.imag(m_linearGain * ((Real)rand()/((Real)RAND_MAX)-0.5f));
|
|
}
|
|
|
|
// Apply low pass filter to limit RF BW
|
|
m_modSample = m_lowpass.filter(m_modSample);
|
|
|
|
// Ramp up/down power at start/end of packet
|
|
if ((m_state == ramp_up) || (m_state == ramp_down))
|
|
{
|
|
m_pow += m_powRamp;
|
|
if ((m_state == ramp_up) && (m_pow >= 0.0f))
|
|
{
|
|
// Finished ramp up, transmit at full gain
|
|
m_state = tx;
|
|
m_pow = 0.0f;
|
|
}
|
|
else if ((m_state == ramp_down) && ( (m_settings.m_rampRange == 0)
|
|
|| (m_settings.m_rampDownBits == 0)
|
|
|| (m_pow <= -(Real)m_settings.m_rampRange)
|
|
))
|
|
{
|
|
m_state = idle;
|
|
// Do we need to retransmit the packet?
|
|
if (m_settings.m_repeat)
|
|
{
|
|
if (m_packetRepeatCount > 0)
|
|
m_packetRepeatCount--;
|
|
if ((m_packetRepeatCount == PacketModSettings::infinitePackets) || (m_packetRepeatCount > 0))
|
|
{
|
|
if (m_settings.m_repeatDelay > 0.0f)
|
|
{
|
|
// Wait before retransmitting
|
|
m_state = wait;
|
|
m_waitCounter = m_settings.m_repeatDelay * m_channelSampleRate;
|
|
}
|
|
else
|
|
{
|
|
// Retransmit immediately
|
|
initTX();
|
|
}
|
|
}
|
|
}
|
|
}
|
|
}
|
|
|
|
Real s = std::real(m_modSample);
|
|
calculateLevel(s);
|
|
}
|
|
|
|
m_demodBuffer[m_demodBufferFill] = audioMod * std::numeric_limits<int16_t>::max();
|
|
++m_demodBufferFill;
|
|
|
|
if (m_demodBufferFill >= m_demodBuffer.size())
|
|
{
|
|
QList<DataFifo*> *dataFifos = MainCore::instance()->getDataPipes().getFifos(m_channel, "demod");
|
|
|
|
if (dataFifos)
|
|
{
|
|
QList<DataFifo*>::iterator it = dataFifos->begin();
|
|
|
|
for (; it != dataFifos->end(); ++it) {
|
|
(*it)->write((quint8*) &m_demodBuffer[0], m_demodBuffer.size() * sizeof(qint16), DataFifo::DataTypeI16);
|
|
}
|
|
}
|
|
|
|
m_demodBufferFill = 0;
|
|
}
|
|
}
|
|
|
|
void PacketModSource::calculateLevel(Real& sample)
|
|
{
|
|
if (m_levelCalcCount < m_levelNbSamples)
|
|
{
|
|
m_peakLevel = std::max(std::fabs(m_peakLevel), sample);
|
|
m_levelSum += sample * sample;
|
|
m_levelCalcCount++;
|
|
}
|
|
else
|
|
{
|
|
m_rmsLevel = sqrt(m_levelSum / m_levelNbSamples);
|
|
m_peakLevelOut = m_peakLevel;
|
|
m_peakLevel = 0.0f;
|
|
m_levelSum = 0.0f;
|
|
m_levelCalcCount = 0;
|
|
}
|
|
}
|
|
|
|
void PacketModSource::applySettings(const PacketModSettings& settings, bool force)
|
|
{
|
|
// Only recreate filters if settings have changed
|
|
if ((settings.m_lpfTaps != m_settings.m_lpfTaps) || (settings.m_rfBandwidth != m_settings.m_rfBandwidth) || force)
|
|
{
|
|
qDebug() << "PacketModSource::applySettings: Creating new lpf with taps " << settings.m_lpfTaps << " rfBW " << settings.m_rfBandwidth;
|
|
m_lowpass.create(settings.m_lpfTaps, m_channelSampleRate, settings.m_rfBandwidth / 2.0);
|
|
}
|
|
if ((settings.m_preEmphasisTau != m_settings.m_preEmphasisTau) || (settings.m_preEmphasisHighFreq != m_settings.m_preEmphasisHighFreq) || force)
|
|
{
|
|
qDebug() << "PacketModSource::applySettings: Creating new preemphasis filter with tau " << settings.m_preEmphasisTau << " highFreq " << settings.m_preEmphasisHighFreq << " sampleRate " << m_channelSampleRate;
|
|
m_preemphasisFilter.configure(m_channelSampleRate, settings.m_preEmphasisTau, settings.m_preEmphasisHighFreq);
|
|
}
|
|
if ((settings.m_bpfLowCutoff != m_settings.m_bpfLowCutoff) || (settings.m_bpfHighCutoff != m_settings.m_bpfHighCutoff)
|
|
|| (settings.m_bpfTaps != m_settings.m_bpfTaps)|| force)
|
|
{
|
|
qDebug() << "PacketModSource::applySettings: Recreating bandpass filter: "
|
|
<< " m_bpfTaps: " << settings.m_bpfTaps
|
|
<< " m_channelSampleRate:" << m_channelSampleRate
|
|
<< " m_bpfLowCutoff: " << settings.m_bpfLowCutoff
|
|
<< " m_bpfHighCutoff: " << settings.m_bpfHighCutoff;
|
|
m_bandpass.create(settings.m_bpfTaps, m_channelSampleRate, settings.m_bpfLowCutoff, settings.m_bpfHighCutoff);
|
|
}
|
|
if ((settings.m_beta != m_settings.m_beta) || (settings.m_symbolSpan != m_settings.m_symbolSpan) || (settings.m_baud != m_settings.m_baud) || force)
|
|
{
|
|
qDebug() << "PacketModSource::applySettings: Recreating pulse shaping filter: "
|
|
<< " beta: " << settings.m_beta
|
|
<< " symbolSpan: " << settings.m_symbolSpan
|
|
<< " channelSampleRate:" << m_channelSampleRate
|
|
<< " baud:" << settings.m_baud;
|
|
m_pulseShape.create(settings.m_beta, m_settings.m_symbolSpan, m_channelSampleRate/settings.m_baud);
|
|
}
|
|
if ((settings.m_polynomial != m_settings.m_polynomial) || force)
|
|
m_scrambler.setPolynomial(settings.m_polynomial);
|
|
if ((settings.m_spectrumRate != m_settings.m_spectrumRate) || force)
|
|
{
|
|
m_interpolatorDistanceRemain = 0;
|
|
m_interpolatorConsumed = false;
|
|
m_interpolatorDistance = (Real) m_channelSampleRate / (Real) settings.m_spectrumRate;
|
|
m_interpolator.create(48, settings.m_spectrumRate, settings.m_spectrumRate / 2.2, 3.0);
|
|
}
|
|
|
|
m_settings = settings;
|
|
|
|
// Precalculate FM sensensity and linear gain to save doing it in the loop
|
|
m_phaseSensitivity = 2.0f * M_PI * m_settings.m_fmDeviation / (double)m_channelSampleRate;
|
|
m_linearGain = powf(10.0f, m_settings.m_gain/20.0f);
|
|
}
|
|
|
|
void PacketModSource::applyChannelSettings(int channelSampleRate, int channelFrequencyOffset, bool force)
|
|
{
|
|
qDebug() << "PacketModSource::applyChannelSettings:"
|
|
<< " channelSampleRate: " << channelSampleRate
|
|
<< " channelFrequencyOffset: " << channelFrequencyOffset
|
|
<< " rfBandwidth: " << m_settings.m_rfBandwidth
|
|
<< " spectrumRate: " << m_settings.m_spectrumRate;
|
|
|
|
if ((channelFrequencyOffset != m_channelFrequencyOffset)
|
|
|| (channelSampleRate != m_channelSampleRate) || force)
|
|
{
|
|
m_carrierNco.setFreq(channelFrequencyOffset, channelSampleRate);
|
|
}
|
|
|
|
if ((m_channelSampleRate != channelSampleRate) || force)
|
|
{
|
|
qDebug() << "PacketModSource::applyChannelSettings: Recreating filters";
|
|
m_lowpass.create(m_settings.m_lpfTaps, channelSampleRate, m_settings.m_rfBandwidth / 2.0);
|
|
qDebug() << "PacketModSource::applyChannelSettings: Recreating bandpass filter: "
|
|
<< " bpfTaps: " << m_settings.m_bpfTaps
|
|
<< " channelSampleRate:" << channelSampleRate
|
|
<< " bpfLowCutoff: " << m_settings.m_bpfLowCutoff
|
|
<< " bpfHighCutoff: " << m_settings.m_bpfHighCutoff;
|
|
m_bandpass.create(m_settings.m_bpfTaps, channelSampleRate, m_settings.m_bpfLowCutoff, m_settings.m_bpfHighCutoff);
|
|
m_preemphasisFilter.configure(channelSampleRate, m_settings.m_preEmphasisTau);
|
|
qDebug() << "PacketModSource::applyChannelSettings: Recreating pulse shaping filter: "
|
|
<< " beta: " << m_settings.m_beta
|
|
<< " symbolSpan: " << m_settings.m_symbolSpan
|
|
<< " channelSampleRate:" << m_channelSampleRate
|
|
<< " baud:" << m_settings.m_baud;
|
|
m_pulseShape.create(m_settings.m_beta, m_settings.m_symbolSpan, channelSampleRate/m_settings.m_baud);
|
|
}
|
|
|
|
if ((m_channelSampleRate != channelSampleRate) || (m_spectrumRate != m_settings.m_spectrumRate) || force)
|
|
{
|
|
m_interpolatorDistanceRemain = 0;
|
|
m_interpolatorConsumed = false;
|
|
m_interpolatorDistance = (Real) channelSampleRate / (Real) m_settings.m_spectrumRate;
|
|
m_interpolator.create(48, m_settings.m_spectrumRate, m_settings.m_spectrumRate / 2.2, 3.0);
|
|
}
|
|
|
|
m_channelSampleRate = channelSampleRate;
|
|
m_channelFrequencyOffset = channelFrequencyOffset;
|
|
m_spectrumRate = m_settings.m_spectrumRate;
|
|
m_samplesPerSymbol = m_channelSampleRate / m_settings.m_baud;
|
|
qDebug() << "m_samplesPerSymbol: " << m_samplesPerSymbol << " (" << m_channelSampleRate << "/" << m_settings.m_baud << ")";
|
|
// Precalculate FM sensensity to save doing it in the loop
|
|
m_phaseSensitivity = 2.0f * M_PI * m_settings.m_fmDeviation / (double)m_channelSampleRate;
|
|
|
|
QList<MessageQueue*> *messageQueues = MainCore::instance()->getMessagePipes().getMessageQueues(m_channel, "reportdemod");
|
|
|
|
if (messageQueues)
|
|
{
|
|
QList<MessageQueue*>::iterator it = messageQueues->begin();
|
|
|
|
for (; it != messageQueues->end(); ++it)
|
|
{
|
|
MainCore::MsgChannelDemodReport *msg = MainCore::MsgChannelDemodReport::create(m_channel, m_channelSampleRate);
|
|
(*it)->push(msg);
|
|
}
|
|
}
|
|
}
|
|
|
|
static bool ax25_ssid(QByteArray& b, int i, int len, uint8_t& ssid)
|
|
{
|
|
if (b[i] == '-')
|
|
{
|
|
if (len > i + 1)
|
|
{
|
|
ssid = b[i+1] - '0';
|
|
if ((len > i + 2) && isdigit(b[i+2])) {
|
|
ssid = (ssid*10) + (b[i+2] - '0');
|
|
}
|
|
if (ssid >= 16)
|
|
{
|
|
qDebug() << "ax25_address: SSID greater than 15 not supported";
|
|
ssid = ssid & 0xf;
|
|
return false;
|
|
}
|
|
else
|
|
{
|
|
return true;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
qDebug() << "ax25_address: SSID number missing";
|
|
return false;
|
|
}
|
|
}
|
|
else
|
|
return false;
|
|
}
|
|
|
|
static uint8_t *ax25_address(uint8_t *p, QString address, uint8_t crrl)
|
|
{
|
|
int len;
|
|
int i;
|
|
QByteArray b;
|
|
uint8_t ssid = 0;
|
|
bool hyphenSeen = false;
|
|
|
|
len = address.length();
|
|
b = address.toUtf8();
|
|
ssid = 0;
|
|
for (i = 0; i < 6; i++)
|
|
{
|
|
if ((i < len) && !hyphenSeen)
|
|
{
|
|
if (b[i] == '-')
|
|
{
|
|
ax25_ssid(b, i, len, ssid);
|
|
hyphenSeen = true;
|
|
*p++ = ' ' << 1;
|
|
}
|
|
else
|
|
{
|
|
*p++ = b[i] << 1;
|
|
}
|
|
}
|
|
else
|
|
{
|
|
*p++ = ' ' << 1;
|
|
}
|
|
}
|
|
if (b[i] == '-')
|
|
{
|
|
ax25_ssid(b, i, len, ssid);
|
|
}
|
|
*p++ = crrl | (ssid << 1);
|
|
|
|
return p;
|
|
}
|
|
|
|
bool PacketModSource::bitsValid()
|
|
{
|
|
return m_bitCount > 0;
|
|
}
|
|
|
|
int PacketModSource::getBit()
|
|
{
|
|
int bit;
|
|
|
|
if (m_bitCount > 0)
|
|
{
|
|
bit = (m_bits[m_byteIdx] >> m_bitIdx) & 1;
|
|
m_bitIdx++;
|
|
m_bitCount--;
|
|
if (m_bitIdx == 8)
|
|
{
|
|
m_byteIdx++;
|
|
m_bitIdx = 0;
|
|
}
|
|
}
|
|
else
|
|
bit = 0;
|
|
|
|
return bit;
|
|
}
|
|
|
|
void PacketModSource::addBit(int bit)
|
|
{
|
|
// Transmit LSB first
|
|
m_bits[m_byteIdx] |= bit << m_bitIdx;
|
|
m_bitIdx++;
|
|
m_bitCount++;
|
|
m_bitCountTotal++;
|
|
if (m_bitIdx == 8)
|
|
{
|
|
m_byteIdx++;
|
|
m_bits[m_byteIdx] = 0;
|
|
m_bitIdx = 0;
|
|
}
|
|
m_last5Bits = ((m_last5Bits << 1) | bit) & 0x1f;
|
|
}
|
|
|
|
void PacketModSource::initTX()
|
|
{
|
|
m_byteIdx = 0;
|
|
m_bitIdx = 0;
|
|
m_bitCount = m_bitCountTotal; // Reset to allow retransmission
|
|
m_nrziBit = 0;
|
|
if (m_settings.m_rampUpBits == 0)
|
|
{
|
|
m_state = tx;
|
|
m_pow = 0.0f;
|
|
}
|
|
else
|
|
{
|
|
m_state = ramp_up;
|
|
m_pow = -(Real)m_settings.m_rampRange;
|
|
m_powRamp = m_settings.m_rampRange/(m_settings.m_rampUpBits * (Real)m_samplesPerSymbol);
|
|
}
|
|
m_scrambler.init();
|
|
}
|
|
|
|
void PacketModSource::addTXPacket(QString callsign, QString to, QString via, QString data)
|
|
{
|
|
uint8_t packet[AX25_MAX_BYTES];
|
|
uint8_t *crc_start;
|
|
uint8_t *packet_end;
|
|
uint8_t *p;
|
|
crc16x25 crc;
|
|
uint16_t crcValue;
|
|
int len;
|
|
int packet_length;
|
|
|
|
// Create AX.25 packet
|
|
p = packet;
|
|
// Flag
|
|
for (int i = 0; i < std::min(m_settings.m_ax25PreFlags, AX25_MAX_FLAGS); i++)
|
|
*p++ = AX25_FLAG;
|
|
crc_start = p;
|
|
// Dest
|
|
p = ax25_address(p, to, 0xe0);
|
|
// From
|
|
p = ax25_address(p, callsign, 0x60);
|
|
// Via
|
|
p = ax25_address(p, via, 0x61);
|
|
// Control
|
|
*p++ = m_settings.m_ax25Control;
|
|
// PID
|
|
*p++ = m_settings.m_ax25PID;
|
|
// Data
|
|
len = data.length();
|
|
memcpy(p, data.toUtf8(), len);
|
|
p += len;
|
|
// CRC (do not include flags)
|
|
crc.calculate(crc_start, p-crc_start);
|
|
crcValue = crc.get();
|
|
*p++ = crcValue & 0xff;
|
|
*p++ = (crcValue >> 8);
|
|
packet_end = p;
|
|
// Flag
|
|
for (int i = 0; i < std::min(m_settings.m_ax25PostFlags, AX25_MAX_FLAGS); i++)
|
|
*p++ = AX25_FLAG;
|
|
|
|
packet_length = p-&packet[0];
|
|
|
|
encodePacket(packet, packet_length, crc_start, packet_end);
|
|
}
|
|
|
|
void PacketModSource::addTXPacket(QByteArray data)
|
|
{
|
|
uint8_t packet[AX25_MAX_BYTES];
|
|
uint8_t *crc_start;
|
|
uint8_t *packet_end;
|
|
uint8_t *p;
|
|
crc16x25 crc;
|
|
uint16_t crcValue;
|
|
int packet_length;
|
|
|
|
// Create AX.25 packet
|
|
p = packet;
|
|
// Flag
|
|
for (int i = 0; i < std::min(m_settings.m_ax25PreFlags, AX25_MAX_FLAGS); i++)
|
|
*p++ = AX25_FLAG;
|
|
crc_start = p;
|
|
// Copy packet payload
|
|
for (int i = 0; i < data.size(); i++)
|
|
*p++ = data[i];
|
|
// CRC (do not include flags)
|
|
crc.calculate(crc_start, p-crc_start);
|
|
crcValue = crc.get();
|
|
*p++ = crcValue & 0xff;
|
|
*p++ = (crcValue >> 8);
|
|
packet_end = p;
|
|
// Flag
|
|
for (int i = 0; i < std::min(m_settings.m_ax25PostFlags, AX25_MAX_FLAGS); i++)
|
|
*p++ = AX25_FLAG;
|
|
|
|
packet_length = p-&packet[0];
|
|
|
|
encodePacket(packet, packet_length, crc_start, packet_end);
|
|
}
|
|
|
|
void PacketModSource::encodePacket(uint8_t *packet, int packet_length, uint8_t *crc_start, uint8_t *packet_end)
|
|
{
|
|
// HDLC bit stuffing
|
|
m_byteIdx = 0;
|
|
m_bitIdx = 0;
|
|
m_last5Bits = 0;
|
|
m_bitCount = 0;
|
|
m_bitCountTotal = 0;
|
|
for (int i = 0; i < packet_length; i++)
|
|
{
|
|
for (int j = 0; j < 8; j++)
|
|
{
|
|
int tx_bit = (packet[i] >> j) & 1;
|
|
// Stuff 0 if last 5 bits are 1s, unless transmitting flag
|
|
// Except for special case of when last 5 bits of CRC are 1s
|
|
if ( ( (packet[i] != AX25_FLAG)
|
|
|| ( (&packet[i] >= crc_start)
|
|
&& ( (&packet[i] < packet_end)
|
|
|| ((&packet[i] == packet_end) && (j == 0))
|
|
)
|
|
)
|
|
)
|
|
&& (m_last5Bits == 0x1f)
|
|
)
|
|
addBit(0);
|
|
addBit(tx_bit);
|
|
}
|
|
}
|
|
m_samplesPerSymbol = m_channelSampleRate / m_settings.m_baud;
|
|
m_packetRepeatCount = m_settings.m_repeatCount;
|
|
initTX();
|
|
// Only reset phases at start of new packet TX, not in initTX(), so that
|
|
// there isn't a discontinuity in phase when repeatedly transmitting a
|
|
// single tone
|
|
m_sampleIdx = 0;
|
|
m_audioPhase = 0.0f;
|
|
m_fmPhase = 0.0;
|
|
|
|
if (m_settings.m_writeToFile)
|
|
m_audioFile.open("packetmod.csv", std::ofstream::out);
|
|
else if (m_audioFile.is_open())
|
|
m_audioFile.close();
|
|
}
|