mirror of https://github.com/hmatuschek/libsdr
Fixed.
Hannes Matuschek
11 years ago
parent
2afdd5060c
commit
fca04605f3
@ -1,15 +1,19 @@
|
||||
IF(SDR_WITH_PORTAUDIO)
|
||||
add_executable(sdr_wavplay sdr_wavplay.cc)
|
||||
target_link_libraries(sdr_wavplay ${LIBS} libsdr)
|
||||
# add_executable(sdr_wavplay sdr_wavplay.cc)
|
||||
# target_link_libraries(sdr_wavplay ${LIBS} libsdr)
|
||||
|
||||
add_executable(sdr_fm sdr_fm.cc)
|
||||
target_link_libraries(sdr_fm ${LIBS} libsdr)
|
||||
# add_executable(sdr_fm sdr_fm.cc)
|
||||
# target_link_libraries(sdr_fm ${LIBS} libsdr)
|
||||
|
||||
add_executable(sdr_rec sdr_rec.cc)
|
||||
target_link_libraries(sdr_rec ${LIBS} libsdr)
|
||||
# add_executable(sdr_rec sdr_rec.cc)
|
||||
# target_link_libraries(sdr_rec ${LIBS} libsdr)
|
||||
|
||||
add_executable(sdr_afsk1200 sdr_afsk1200.cc)
|
||||
target_link_libraries(sdr_afsk1200 ${LIBS} libsdr)
|
||||
|
||||
add_executable(sdr_rtty sdr_rtty.cc)
|
||||
target_link_libraries(sdr_rtty ${LIBS} libsdr)
|
||||
|
||||
ENDIF(SDR_WITH_PORTAUDIO)
|
||||
|
||||
|
||||
|
||||
@ -0,0 +1,168 @@
|
||||
#include "afsk.hh"
|
||||
#include "logger.hh"
|
||||
#include "traits.hh"
|
||||
#include "interpolate.hh"
|
||||
|
||||
using namespace sdr;
|
||||
|
||||
|
||||
AFSK::AFSK(double baud, double Fmark, double Fspace, Mode mode)
|
||||
: Sink<int16_t>(), Source(), _baud(baud), _Fmark(Fmark), _Fspace(Fspace), _mode(mode)
|
||||
{
|
||||
// pass...
|
||||
}
|
||||
|
||||
AFSK::~AFSK() {
|
||||
// pass...
|
||||
}
|
||||
|
||||
void
|
||||
AFSK::config(const Config &src_cfg)
|
||||
{
|
||||
// Check if config is complete
|
||||
if (!src_cfg.hasType() || !src_cfg.hasSampleRate()) { return; }
|
||||
|
||||
// Check if buffer type matches
|
||||
if (Config::typeId<int16_t>() != src_cfg.type()) {
|
||||
ConfigError err;
|
||||
err << "Can not configure AFSK1200: Invalid type " << src_cfg.type()
|
||||
<< ", expected " << Config::typeId<int16_t>();
|
||||
throw err;
|
||||
}
|
||||
|
||||
// The input sample rate
|
||||
_sampleRate = src_cfg.sampleRate();
|
||||
|
||||
// Samples per bit
|
||||
_corrLen = int(_sampleRate/_baud);
|
||||
// Compute symbol rate:
|
||||
_symbolRate = std::max(_baud, _baud*_corrLen);
|
||||
|
||||
// Samples per symbol (fractional):
|
||||
_muIncr = _sampleRate/_symbolRate;
|
||||
_mu = _muIncr;
|
||||
// Delayline for interpolating sub-sampler
|
||||
_dl = Buffer<float>(2*8);
|
||||
for (size_t i=0; i<(2*8); i++) { _dl[i] = 0; }
|
||||
_dl_idx = 0;
|
||||
|
||||
// Assemble phase LUT:
|
||||
_markLUT = Buffer< std::complex<float> >(_corrLen);
|
||||
_spaceLUT = Buffer< std::complex<float> >(_corrLen);
|
||||
|
||||
// Allocate ring-buffers for mark and space symbols
|
||||
_markHist = Buffer< std::complex<float> >(_corrLen);
|
||||
_spaceHist = Buffer< std::complex<float> >(_corrLen);
|
||||
_symbols = Buffer<int16_t>(_corrLen);
|
||||
|
||||
// Initialize LUTs and ring-buffers
|
||||
double phiMark=0, phiSpace=0;
|
||||
for (size_t i=0; i<_corrLen; i++) {
|
||||
_markLUT[i] = std::exp(std::complex<float>(0.0, phiMark));
|
||||
_spaceLUT[i] = std::exp(std::complex<float>(0.0, phiSpace));
|
||||
phiMark += (2.*M_PI*_Fmark)/_sampleRate;
|
||||
phiSpace += (2.*M_PI*_Fspace)/_sampleRate;
|
||||
// Apply Window functions
|
||||
//_markLUT[i] *= (0.42 - 0.5*cos((2*M_PI*i)/_corrLen) + 0.08*cos((4*M_PI*i)/_corrLen));
|
||||
//_spaceLUT[i] *= (0.42 - 0.5*cos((2*M_PI*i)/_corrLen) + 0.08*cos((4*M_PI*i)/_corrLen));
|
||||
_markHist[i] = 0; _spaceHist[i] = 0; _symbols[i] = 0;
|
||||
}
|
||||
// Ring buffer indices
|
||||
_lutIdx = 0; _symbolIdx = 0;
|
||||
|
||||
// Get phase increment per symbol
|
||||
_phase = 0; _omega = _baud/_symbolRate;
|
||||
// PLL limits +/- 10% around _omega
|
||||
_omegaMin = _omega - 0.005*_omega;
|
||||
_omegaMax = _omega + 0.005*_omega;
|
||||
// PLL gain
|
||||
_gainOmega = 0.0005;
|
||||
|
||||
_symSum = 0;
|
||||
_lastSymSum = 0;
|
||||
|
||||
// Allocate output buffer:
|
||||
_buffer = Buffer<uint8_t>(src_cfg.bufferSize()/_corrLen + 1);
|
||||
|
||||
LogMessage msg(LOG_DEBUG);
|
||||
msg << "Config AFSK node: " << std::endl
|
||||
<< " input sample rate: " << _sampleRate << " Hz" << std::endl
|
||||
<< " samples per symbol: " << _muIncr << std::endl
|
||||
<< " symbols per bit: " << _corrLen << std::endl
|
||||
<< " symbol rate: " << _symbolRate << " Hz" << std::endl
|
||||
<< " bit rate: " << _symbolRate/_corrLen << " baud" << std::endl
|
||||
<< " phase incr/symbol: " << float(_omega) << std::endl
|
||||
<< " bit mode: " << ((TRANSITION == _mode) ? "transition" : "normal");
|
||||
Logger::get().log(msg);
|
||||
|
||||
// Forward config.
|
||||
this->setConfig(Config(Traits<uint8_t>::scalarId, _baud, _buffer.size(), 1));
|
||||
}
|
||||
|
||||
|
||||
void
|
||||
AFSK::process(const Buffer<int16_t> &buffer, bool allow_overwrite)
|
||||
{
|
||||
size_t i=0, o=0;
|
||||
while (i<buffer.size()) {
|
||||
// Update sub-sampler
|
||||
while ((_mu>=1) && (i<buffer.size())) {
|
||||
_markHist[_lutIdx] = float(buffer[i])*_markLUT[_lutIdx];
|
||||
_spaceHist[_lutIdx] = float(buffer[i])*_spaceLUT[_lutIdx];
|
||||
// inc _lutIdx, modulo LUT length
|
||||
_lutIdx++; if (_lutIdx==_corrLen) { _lutIdx=0; }
|
||||
// Get symbol from FIR filter results
|
||||
float symbol = _getSymbol();
|
||||
// Put symbol into delay line
|
||||
_dl[_dl_idx] = symbol; _dl[_dl_idx+8] = symbol;
|
||||
_dl_idx = (_dl_idx+1)%8; _mu -= 1; i++;
|
||||
}
|
||||
|
||||
if (_mu >= 1) { continue; }
|
||||
|
||||
// Get interpolated symbol
|
||||
float symbol = interpolate(_dl.sub(_dl_idx, 8), _mu); _mu += _muIncr;
|
||||
// store symbol
|
||||
_lastSymSum = _symSum;
|
||||
_symSum -= _symbols[_symbolIdx];
|
||||
_symbols[_symbolIdx] = ( (symbol>=0) ? 1 : -1 );
|
||||
_symSum += _symbols[_symbolIdx];
|
||||
_symbolIdx = ((_symbolIdx+1) % _corrLen);
|
||||
// Advance phase
|
||||
_phase += _omega;
|
||||
|
||||
// Sample bit
|
||||
if (_phase >= 1) {
|
||||
// Modulo "2 pi", phase is defined on the interval [0,1)
|
||||
while (_phase>=1) { _phase -= 1; }
|
||||
// Estimate bit by majority vote on all symbols
|
||||
_lastBits = ((_lastBits<<1) | (_symSum>0));
|
||||
// Put decoded bit in output buffer
|
||||
if (TRANSITION == _mode) {
|
||||
// transition -> 0; no transition -> 1
|
||||
_buffer[o++] = ((_lastBits ^ (_lastBits >> 1) ^ 1) & 1);
|
||||
} else {
|
||||
// mark -> 1, space -> 0
|
||||
_buffer[o++] = _lastBits & 1;
|
||||
}
|
||||
}
|
||||
|
||||
// If there was a symbol transition
|
||||
if (((_lastSymSum < 0) && (_symSum>=0)) || ((_lastSymSum >= 0) && (_symSum<0))) {
|
||||
// Phase correction
|
||||
/**std::cerr << "Transition at phi=" << _phase << std::endl
|
||||
<< " update omega from " << _omega << " to "; */
|
||||
// transition at [-pi,0] -> increase omega
|
||||
if (_phase < 0.5) { _omega += _gainOmega*(0.5-_phase); }
|
||||
// transition at [0,pi] -> decrease omega
|
||||
else { _omega -= _gainOmega*(_phase-0.5); }
|
||||
// Limit omega
|
||||
_omega = std::min(_omegaMax, std::max(_omegaMin, _omega));
|
||||
//_phase += _gainOmega*(_phase-0.5);
|
||||
/* std::cerr << _omega << std::endl; */
|
||||
}
|
||||
}
|
||||
|
||||
if (0 < o) { this->send(_buffer.head(o)); }
|
||||
}
|
||||
|
||||
@ -0,0 +1,111 @@
|
||||
#ifndef __SDR_AFSK_HH__
|
||||
#define __SDR_AFSK_HH__
|
||||
|
||||
#include "node.hh"
|
||||
|
||||
namespace sdr {
|
||||
|
||||
/** A simple (Audio) Frequency Shift Keying (AFSK) demodulator.
|
||||
* This node consists of two convolution peak-filters at the mark and space frequencies, a
|
||||
* interpolating sub-sampler to match the baud-rate exactly and a PLL to lock to the symbol
|
||||
* transitions. The node will decode the (A)FSK signal and will send a bit-stream (uint8_t).
|
||||
* @ingroup demodulator */
|
||||
class AFSK: public Sink<int16_t>, public Source
|
||||
{
|
||||
public:
|
||||
/** Possible bit decoding modes. */
|
||||
typedef enum {
|
||||
NORMAL, ///< Normal mode (i.e. mark -> 1, space -> 0).
|
||||
TRANSITION ///< Transition mode (i.e. transition -> 0, no transition -> 1).
|
||||
} Mode;
|
||||
|
||||
public:
|
||||
/** Constructs a AFSK node with the specified @c baud rate and @c Fmark, @c Fspace frequencies.
|
||||
* The default valuse corresponds to those used for 1200 baud packet radio. */
|
||||
AFSK(double baud=1200.0, double Fmark=1200.0, double Fspace=2200.0,
|
||||
Mode mode=TRANSITION);
|
||||
/** Destructor. */
|
||||
virtual ~AFSK();
|
||||
|
||||
/** Configures the node. */
|
||||
virtual void config(const Config &src_cfg);
|
||||
/** Processes the given buffer. */
|
||||
virtual void process(const Buffer<int16_t> &buffer, bool allow_overwrite);
|
||||
|
||||
protected:
|
||||
/** Performs the convolution filtering of the mark & space frequencies. */
|
||||
inline double _getSymbol() {
|
||||
std::complex<float> markSum(0), spaceSum(0);
|
||||
for (size_t i=0; i<_corrLen; i++) {
|
||||
markSum += _markHist[i];
|
||||
spaceSum += _spaceHist[i];
|
||||
}
|
||||
double f = markSum.real()*markSum.real() +
|
||||
markSum.imag()*markSum.imag() -
|
||||
spaceSum.real()*spaceSum.real() -
|
||||
spaceSum.imag()*spaceSum.imag();
|
||||
return f;
|
||||
}
|
||||
|
||||
|
||||
protected:
|
||||
/** The sample rate of the input signal. */
|
||||
float _sampleRate;
|
||||
/** A multiple of the baud rate. */
|
||||
float _symbolRate;
|
||||
/** The baud rate. */
|
||||
float _baud;
|
||||
/** Mark "tone" frequency. */
|
||||
float _Fmark;
|
||||
/** Space "tone" frequency. */
|
||||
float _Fspace;
|
||||
/** Bit encoding mode. */
|
||||
Mode _mode;
|
||||
/** Correlation length, the number of "symbols" per bit. */
|
||||
uint32_t _corrLen;
|
||||
/** The current FIR filter LUT index. */
|
||||
uint32_t _lutIdx;
|
||||
/** Mark frequency FIR filter LUT. */
|
||||
Buffer< std::complex<float> > _markLUT;
|
||||
/** Space frequency FIR filter LUT. */
|
||||
Buffer< std::complex<float> > _spaceLUT;
|
||||
|
||||
/** FIR filter buffer. */
|
||||
Buffer< std::complex<float> > _markHist;
|
||||
/** FIR filter buffer. */
|
||||
Buffer< std::complex<float> > _spaceHist;
|
||||
|
||||
/** Symbol subsampling counter. */
|
||||
float _mu;
|
||||
/** Symbol subsampling. */
|
||||
float _muIncr;
|
||||
/** Delay line for the 8-pole interpolation filter. */
|
||||
Buffer< float > _dl;
|
||||
/** Delay line index. */
|
||||
size_t _dl_idx;
|
||||
|
||||
Buffer<int16_t> _symbols;
|
||||
size_t _symbolIdx;
|
||||
int32_t _symSum;
|
||||
int32_t _lastSymSum;
|
||||
|
||||
/** Last received bits. */
|
||||
uint32_t _lastBits;
|
||||
/** Current PLL phase. */
|
||||
float _phase;
|
||||
/** PLL phase speed. */
|
||||
float _omega;
|
||||
/** Maximum PLL phase speed. */
|
||||
float _omegaMin;
|
||||
/** Minimum PLL phase speed. */
|
||||
float _omegaMax;
|
||||
/** PLL gain. */
|
||||
float _gainOmega;
|
||||
|
||||
/** Output buffer. */
|
||||
Buffer<uint8_t> _buffer;
|
||||
};
|
||||
|
||||
|
||||
}
|
||||
#endif // __SDR_AFSK_HH__
|
||||
@ -0,0 +1,173 @@
|
||||
#include "ax25.hh"
|
||||
#include "logger.hh"
|
||||
#include "traits.hh"
|
||||
|
||||
using namespace sdr;
|
||||
|
||||
|
||||
static const uint16_t crc_ccitt_table[] = {
|
||||
0x0000, 0x1189, 0x2312, 0x329b, 0x4624, 0x57ad, 0x6536, 0x74bf,
|
||||
0x8c48, 0x9dc1, 0xaf5a, 0xbed3, 0xca6c, 0xdbe5, 0xe97e, 0xf8f7,
|
||||
0x1081, 0x0108, 0x3393, 0x221a, 0x56a5, 0x472c, 0x75b7, 0x643e,
|
||||
0x9cc9, 0x8d40, 0xbfdb, 0xae52, 0xdaed, 0xcb64, 0xf9ff, 0xe876,
|
||||
0x2102, 0x308b, 0x0210, 0x1399, 0x6726, 0x76af, 0x4434, 0x55bd,
|
||||
0xad4a, 0xbcc3, 0x8e58, 0x9fd1, 0xeb6e, 0xfae7, 0xc87c, 0xd9f5,
|
||||
0x3183, 0x200a, 0x1291, 0x0318, 0x77a7, 0x662e, 0x54b5, 0x453c,
|
||||
0xbdcb, 0xac42, 0x9ed9, 0x8f50, 0xfbef, 0xea66, 0xd8fd, 0xc974,
|
||||
0x4204, 0x538d, 0x6116, 0x709f, 0x0420, 0x15a9, 0x2732, 0x36bb,
|
||||
0xce4c, 0xdfc5, 0xed5e, 0xfcd7, 0x8868, 0x99e1, 0xab7a, 0xbaf3,
|
||||
0x5285, 0x430c, 0x7197, 0x601e, 0x14a1, 0x0528, 0x37b3, 0x263a,
|
||||
0xdecd, 0xcf44, 0xfddf, 0xec56, 0x98e9, 0x8960, 0xbbfb, 0xaa72,
|
||||
0x6306, 0x728f, 0x4014, 0x519d, 0x2522, 0x34ab, 0x0630, 0x17b9,
|
||||
0xef4e, 0xfec7, 0xcc5c, 0xddd5, 0xa96a, 0xb8e3, 0x8a78, 0x9bf1,
|
||||
0x7387, 0x620e, 0x5095, 0x411c, 0x35a3, 0x242a, 0x16b1, 0x0738,
|
||||
0xffcf, 0xee46, 0xdcdd, 0xcd54, 0xb9eb, 0xa862, 0x9af9, 0x8b70,
|
||||
0x8408, 0x9581, 0xa71a, 0xb693, 0xc22c, 0xd3a5, 0xe13e, 0xf0b7,
|
||||
0x0840, 0x19c9, 0x2b52, 0x3adb, 0x4e64, 0x5fed, 0x6d76, 0x7cff,
|
||||
0x9489, 0x8500, 0xb79b, 0xa612, 0xd2ad, 0xc324, 0xf1bf, 0xe036,
|
||||
0x18c1, 0x0948, 0x3bd3, 0x2a5a, 0x5ee5, 0x4f6c, 0x7df7, 0x6c7e,
|
||||
0xa50a, 0xb483, 0x8618, 0x9791, 0xe32e, 0xf2a7, 0xc03c, 0xd1b5,
|
||||
0x2942, 0x38cb, 0x0a50, 0x1bd9, 0x6f66, 0x7eef, 0x4c74, 0x5dfd,
|
||||
0xb58b, 0xa402, 0x9699, 0x8710, 0xf3af, 0xe226, 0xd0bd, 0xc134,
|
||||
0x39c3, 0x284a, 0x1ad1, 0x0b58, 0x7fe7, 0x6e6e, 0x5cf5, 0x4d7c,
|
||||
0xc60c, 0xd785, 0xe51e, 0xf497, 0x8028, 0x91a1, 0xa33a, 0xb2b3,
|
||||
0x4a44, 0x5bcd, 0x6956, 0x78df, 0x0c60, 0x1de9, 0x2f72, 0x3efb,
|
||||
0xd68d, 0xc704, 0xf59f, 0xe416, 0x90a9, 0x8120, 0xb3bb, 0xa232,
|
||||
0x5ac5, 0x4b4c, 0x79d7, 0x685e, 0x1ce1, 0x0d68, 0x3ff3, 0x2e7a,
|
||||
0xe70e, 0xf687, 0xc41c, 0xd595, 0xa12a, 0xb0a3, 0x8238, 0x93b1,
|
||||
0x6b46, 0x7acf, 0x4854, 0x59dd, 0x2d62, 0x3ceb, 0x0e70, 0x1ff9,
|
||||
0xf78f, 0xe606, 0xd49d, 0xc514, 0xb1ab, 0xa022, 0x92b9, 0x8330,
|
||||
0x7bc7, 0x6a4e, 0x58d5, 0x495c, 0x3de3, 0x2c6a, 0x1ef1, 0x0f78
|
||||
};
|
||||
|
||||
static inline bool check_crc_ccitt(const uint8_t *buf, int cnt)
|
||||
{
|
||||
uint32_t crc = 0xffff;
|
||||
for (; cnt > 0; cnt--, buf++) {
|
||||
crc = (crc >> 8) ^ crc_ccitt_table[(crc ^ (*buf)) & 0xff];
|
||||
}
|
||||
return (crc & 0xffff) == 0xf0b8;
|
||||
}
|
||||
|
||||
|
||||
|
||||
AX25::AX25()
|
||||
: Sink<uint8_t>(), Source()
|
||||
{
|
||||
// pass...
|
||||
}
|
||||
|
||||
AX25::~AX25() {
|
||||
// pass...
|
||||
}
|
||||
|
||||
void
|
||||
AX25::config(const Config &src_cfg) {
|
||||
if (! src_cfg.hasType()) { return; }
|
||||
// Check if buffer type matches
|
||||
if (Config::typeId<uint8_t>() != src_cfg.type()) {
|
||||
ConfigError err;
|
||||
err << "Can not configure AX25: Invalid type " << src_cfg.type()
|
||||
<< ", expected " << Config::typeId<uint8_t>();
|
||||
throw err;
|
||||
}
|
||||
|
||||
_bitstream = 0;
|
||||
_bitbuffer = 0;
|
||||
_state = 0;
|
||||
_ptr = _rxbuffer;
|
||||
|
||||
// Allocate output buffer
|
||||
_buffer = Buffer<uint8_t>(512);
|
||||
|
||||
LogMessage msg(LOG_DEBUG);
|
||||
msg << "Config AX.25 node.";
|
||||
Logger::get().log(msg);
|
||||
|
||||
// propergate config
|
||||
this->setConfig(Config(Traits<uint8_t>::scalarId, 0, 512, 1));
|
||||
}
|
||||
|
||||
void
|
||||
AX25::process(const Buffer<uint8_t> &buffer, bool allow_overwrite)
|
||||
{
|
||||
for (size_t i=0; i<buffer.size(); i++) {
|
||||
// Store bit in stream
|
||||
_bitstream = ((_bitstream << 1) | (buffer[i] & 0x01));
|
||||
|
||||
// Check for sync byte
|
||||
if ((_bitstream & 0xff) == 0x7e) {
|
||||
if ((1==_state) && ((_ptr - _rxbuffer) > 2)) {
|
||||
*_ptr = 0;
|
||||
if (! check_crc_ccitt(_rxbuffer, _ptr-_rxbuffer)) {
|
||||
LogMessage msg(LOG_DEBUG);
|
||||
msg << "AX.25: Received invalid buffer: " << _rxbuffer;
|
||||
Logger::get().log(msg);
|
||||
} else {
|
||||
bool addrExt;
|
||||
std::string src, dst;
|
||||
int srcSSID, dstSSID;
|
||||
unpackCall(_rxbuffer, dst, dstSSID, addrExt);
|
||||
unpackCall(_rxbuffer+7, src, srcSSID, addrExt);
|
||||
std::cerr << "RX: " << src << "-" << srcSSID
|
||||
<< " > " << dst << "-" << dstSSID << std::endl
|
||||
<< " " << _rxbuffer+14 << std::endl;
|
||||
memcpy(_buffer.ptr(), _rxbuffer, _ptr-_rxbuffer);
|
||||
this->send(_buffer.head(_ptr-_rxbuffer));
|
||||
}
|
||||
}
|
||||
// Receive data
|
||||
_state = 1;
|
||||
_ptr = _rxbuffer;
|
||||
_bitbuffer = 0x80;
|
||||
continue;
|
||||
}
|
||||
|
||||
// If 7 ones are received in a row -> error, wait or sync byte
|
||||
if ((_bitstream & 0x7f) == 0x7f) { _state = 0; continue; }
|
||||
|
||||
// If state == wait for sync byte -> receive next bit
|
||||
if (!_state) { continue; }
|
||||
|
||||
/* stuffed bit */
|
||||
if ((_bitstream & 0x3f) == 0x3e) { continue; }
|
||||
|
||||
// prepend bit to bitbuffer
|
||||
/// @todo Double check this!!!
|
||||
_bitbuffer |= ((_bitstream & 0x01) << 8);
|
||||
|
||||
// If 8 bits have been received (stored in b8-b1 of _bitbuffer)
|
||||
if (_bitbuffer & 0x01) {
|
||||
// Check for buffer overrun
|
||||
if ((_ptr-_rxbuffer) >= 512) {
|
||||
Logger::get().log(LogMessage(LOG_DEBUG, "AX.25 packet too long."));
|
||||
// Wait for next sync byte
|
||||
_state = 0;
|
||||
continue;
|
||||
}
|
||||
|
||||
// Store received byte and ...
|
||||
*_ptr++ = (_bitbuffer >> 1);
|
||||
// reset bit buffer
|
||||
_bitbuffer = 0x80;
|
||||
continue;
|
||||
}
|
||||
|
||||
// Shift bitbuffer one to the left
|
||||
_bitbuffer >>= 1;
|
||||
}
|
||||
}
|
||||
|
||||
|
||||
void
|
||||
AX25::unpackCall(const uint8_t *buffer, std::string &call, int &ssid, bool &addrExt) {
|
||||
size_t length = 0; call.resize(6);
|
||||
for (size_t i=0; i<6; i++) {
|
||||
call.at(i) = char(buffer[i]>>1);
|
||||
if (' ' != call.at(i)) { length++; }
|
||||
}
|
||||
call.resize(length);
|
||||
ssid = int( (buffer[6] & 0x1f) >> 1);
|
||||
addrExt = !bool(buffer[6] & 0x01);
|
||||
}
|
||||
|
||||
@ -0,0 +1,55 @@
|
||||
#ifndef __SDR_AX25_HH__
|
||||
#define __SDR_AX25_HH__
|
||||
|
||||
#include "node.hh"
|
||||
|
||||
|
||||
namespace sdr {
|
||||
|
||||
/** Decodes AX25 (PacketRadio) messages from a bit stream.
|
||||
*
|
||||
* In conjecture with the (A)FSK demodulator, the AX25 can be used to receive packet radio or APRS
|
||||
* messages. AX25 is usually transmitted as FSK in transition mode, means the bits aren't
|
||||
* encoded by mark & space tones but rather as a transition from mark to space or in reverse. Hence
|
||||
* the FSK node needs to be configured in transition mode.
|
||||
*
|
||||
* The node does not process the actual AX.25 packages, it only checks the frame check sequence and
|
||||
* forwards the AX.25 datagram to all connected sinks on success. The receiving node is responsible
|
||||
* for unpacking and handling the received datagram.
|
||||
*
|
||||
* @ingroup datanode */
|
||||
class AX25: public Sink<uint8_t>, public Source
|
||||
{
|
||||
public:
|
||||
/** Constructor. */
|
||||
AX25();
|
||||
/** Destructor. */
|
||||
virtual ~AX25();
|
||||
/** Configures the node. */
|
||||
virtual void config(const Config &src_cfg);
|
||||
/** Processes the bit stream. */
|
||||
virtual void process(const Buffer<uint8_t> &buffer, bool allow_overwrite);
|
||||
|
||||
static void unpackCall(const uint8_t *buffer, std::string &call, int &ssid, bool &addrExt);
|
||||
|
||||
protected:
|
||||
/** The last bits. */
|
||||
uint32_t _bitstream;
|
||||
/** A buffer of received bits. */
|
||||
uint32_t _bitbuffer;
|
||||
/** The current state. */
|
||||
uint32_t _state;
|
||||
|
||||
/** Message buffer. */
|
||||
uint8_t _rxbuffer[512];
|
||||
/** Insert-pointer to the buffer. */
|
||||
uint8_t *_ptr;
|
||||
|
||||
/** Output buffer. */
|
||||
Buffer<uint8_t> _buffer;
|
||||
};
|
||||
|
||||
}
|
||||
|
||||
|
||||
#endif // __SDR_AX25_HH__
|
||||
@ -0,0 +1,111 @@
|
||||
#include "baudot.hh"
|
||||
#include "traits.hh"
|
||||
#include "logger.hh"
|
||||
|
||||
|
||||
using namespace sdr;
|
||||
|
||||
// Baudot code tables
|
||||
char Baudot::_letter[32] = { 0, 'E','\n', 'A', ' ', 'S', 'I', 'U','\n', 'D', 'R', 'J', 'N', 'F',
|
||||
'C', 'K', 'T', 'Z', 'L', 'W', 'H', 'Y', 'P', 'Q', 'O', 'B', 'G', 0,
|
||||
'M', 'X', 'V', 0};
|
||||
char Baudot::_figure[32] = { 0, '3','\n', '-', ' ','\a', '8', '7','\n', '?', '4','\'', ',', '!',
|
||||
':', '(', '5', '"', ')', '2', '#', '6', '0', '1', '9', '?', '&', 0,
|
||||
'.', '/', ';', 0};
|
||||
|
||||
// Some special codes
|
||||
#define CHAR_NUL 0
|
||||
#define CHAR_STF 27
|
||||
#define CHAR_STL 31
|
||||
#define CHAR_SPA 4
|
||||
|
||||
|
||||
Baudot::Baudot(StopBits stopBits)
|
||||
: Sink<uint8_t>(), Source(), _mode(LETTERS)
|
||||
{
|
||||
switch (stopBits) {
|
||||
case STOP1:
|
||||
// Pattern xx11 xxxx xxxx xx00
|
||||
// Mask 0011 0000 0000 0011
|
||||
_stopHBits = 2;
|
||||
_bitsPerSymbol = 14;
|
||||
_pattern = 0x3000;
|
||||
_mask = 0x3003;
|
||||
break;
|
||||
case STOP15:
|
||||
// Pattern x11x xxxx xxxx x000
|
||||
// Mask 0110 0000 0000 0111
|
||||
_stopHBits = 3;
|
||||
_bitsPerSymbol = 15;
|
||||
_pattern = 0x6000;
|
||||
_mask = 0x6007;
|
||||
break;
|
||||
case STOP2:
|
||||
// Pattern 11xx xxxx xxxx 0000
|
||||
// Mask 1100 0000 0000 1111
|
||||
_stopHBits = 4;
|
||||
_bitsPerSymbol = 16;
|
||||
_pattern = 0xC000;
|
||||
_mask = 0xC00F;
|
||||
break;
|
||||
}
|
||||
}
|
||||
|
||||
void
|
||||
Baudot::config(const Config &src_cfg) {
|
||||
if (! src_cfg.hasType()) { return; }
|
||||
// Check if buffer type matches
|
||||
if (Config::typeId<uint8_t>() != src_cfg.type()) {
|
||||
ConfigError err;
|
||||
err << "Can not configure Baudot: Invalid type " << src_cfg.type()
|
||||
<< ", expected " << Config::typeId<uint8_t>();
|
||||
throw err;
|
||||
}
|
||||
|
||||
// Init (half) bit stream and counter
|
||||
_bitstream = 0;
|
||||
_bitcount = 0;
|
||||
|
||||
// Compute buffer size.
|
||||
size_t buffer_size = (src_cfg.bufferSize()/(2*_bitsPerSymbol))+1;
|
||||
_buffer = Buffer<uint8_t>(buffer_size);
|
||||
|
||||
LogMessage msg(LOG_DEBUG);
|
||||
msg << "Config Baudot node: " << std::endl
|
||||
<< " input sample rate: " << src_cfg.sampleRate() << " half-bits/s" << std::endl
|
||||
<< " start bits: " << 1 << std::endl
|
||||
<< " stop bits: " << float(_stopHBits)/2 << std::endl;
|
||||
Logger::get().log(msg);
|
||||
|
||||
// propergate config
|
||||
this->setConfig(Config(Traits<uint8_t>::scalarId, 0, buffer_size, 1));
|
||||
}
|
||||
|
||||
|
||||
void
|
||||
Baudot::process(const Buffer<uint8_t> &buffer, bool allow_overwrite)
|
||||
{
|
||||
size_t o=0;
|
||||
for (size_t i=0; i<buffer.size(); i++) {
|
||||
_bitstream = (_bitstream << 1) | (buffer[i] & 0x1); _bitcount++;
|
||||
// Check if symbol as received:
|
||||
if ((_bitsPerSymbol <= _bitcount) && (_pattern == (_bitstream & _mask))) {
|
||||
_bitcount = 0;
|
||||
// Unpack 5bit baudot code
|
||||
uint8_t code = 0;
|
||||
for (int j=0; j<5; j++) {
|
||||
int shift = _stopHBits + 2*j;
|
||||
code |= (((_bitstream>>shift)&0x01)<<j);
|
||||
}
|
||||
// Decode to ASCII
|
||||
if (CHAR_STL == code) { _mode = LETTERS; }
|
||||
else if (CHAR_STF == code) { _mode = FIGURES; }
|
||||
else {
|
||||
if (CHAR_SPA == code) { _mode = LETTERS; }
|
||||
if (LETTERS == _mode) { _buffer[o++] = _letter[code]; }
|
||||
else { _buffer[o++] = _figure[code]; }
|
||||
}
|
||||
}
|
||||
}
|
||||
if (0 < o) { this->send(_buffer.head(o)); }
|
||||
}
|
||||
@ -0,0 +1,72 @@
|
||||
#ifndef __SDR_BAUDOT_HH__
|
||||
#define __SDR_BAUDOT_HH__
|
||||
|
||||
#include "node.hh"
|
||||
#include <map>
|
||||
|
||||
namespace sdr {
|
||||
|
||||
/** Implements a Baudot decoder. Inconjecture with the (A)FSK demodulator, it enables the
|
||||
* reception of radio teletype (RTTY) messages.
|
||||
*
|
||||
* Please note that a baudot encoded char is usually transmitted in a frame with one start bit and
|
||||
* 1, 1.5 or 2 stop bits. Hence this node expects to receive two bits for one decoded bit in order
|
||||
* to detect the 1.5 stop bits reliably.
|
||||
*
|
||||
* I.e. to receive a 45.45 baud RTTY signal, the (A)FSK demodulator need to be configured for
|
||||
* 90.90 baud (= 2*45.45 baud).
|
||||
* @ingroup datanodes */
|
||||
class Baudot: public Sink<uint8_t>, public Source
|
||||
{
|
||||
public:
|
||||
/** Specifies the current code-tables. */
|
||||
typedef enum {
|
||||
LETTERS, ///< Letters.
|
||||
FIGURES ///< Numbers, symbols etc.
|
||||
} Mode;
|
||||
|
||||
/** Specifies the number of stop bits. */
|
||||
typedef enum {
|
||||
STOP1, ///< 1 stop bit.
|
||||
STOP15, ///< 1.5 stop bits.
|
||||
STOP2 ///< 2 stop bits.
|
||||
} StopBits;
|
||||
|
||||
public:
|
||||
/** Constructor. */
|
||||
Baudot(StopBits stopBits = STOP15);
|
||||
|
||||
/** Configures the node. */
|
||||
virtual void config(const Config &src_cfg);
|
||||
/** Processes the bit-stream. */
|
||||
virtual void process(const Buffer<uint8_t> &buffer, bool allow_overwrite);
|
||||
|
||||
protected:
|
||||
/** Code table for letters. */
|
||||
static char _letter[32];
|
||||
/** Code table for symbols or figure (i.e. numbers). */
|
||||
static char _figure[32];
|
||||
/** The last bits received. */
|
||||
uint16_t _bitstream;
|
||||
/** The number of bits received. */
|
||||
size_t _bitcount;
|
||||
|
||||
/** The currently selected table. */
|
||||
Mode _mode;
|
||||
|
||||
/** Specifies the number of half bits per symbol. */
|
||||
size_t _bitsPerSymbol;
|
||||
/** Specifies the frame pattern. */
|
||||
uint16_t _pattern;
|
||||
/** Specifies the frame mask. */
|
||||
uint16_t _mask;
|
||||
/** Number of half bits forming the stop bit. */
|
||||
uint16_t _stopHBits;
|
||||
|
||||
/** The output buffer. */
|
||||
Buffer<uint8_t> _buffer;
|
||||
};
|
||||
|
||||
}
|
||||
|
||||
#endif // BAUDOT_HH
|
||||
Loading…
Reference in New Issue