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Implemented M17 EOT marker

This commit is contained in:
Jacob McSwain 2022-07-16 04:53:43 -05:00 committed by Silvano Seva
parent a22aceb576
commit fa33f15417
3 changed files with 41 additions and 22 deletions
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1
openrtx/include/protocols/M17/M17Constants.hpp
View File

@ -41,6 +41,7 @@ static constexpr syncw_t LSF_SYNC_WORD = {0x55, 0xF7}; // LSF sync word
static constexpr syncw_t BERT_SYNC_WORD = {0xDF, 0x55}; // BERT data sync word
static constexpr syncw_t STREAM_SYNC_WORD = {0xFF, 0x5D}; // Stream data sync word
static constexpr syncw_t PACKET_SYNC_WORD = {0x75, 0xFF}; // Packet data sync word
static constexpr syncw_t EOT_SYNC_WORD = {0x55, 0x5D}; // End of transmission sync word
} // namespace M17

6
openrtx/include/protocols/M17/M17Modulator.hpp
View File

@ -58,7 +58,7 @@ public:
void init();
/**
* Shutdown modulator and deallocate data buffers.
* Forcefully shutdown modulator and deallocate data buffers.
*/
void terminate();
@ -89,6 +89,9 @@ private:
*/
void sendBaseband();
/** Gracefully end the transmission **/
void stop();
static constexpr size_t M17_TX_SAMPLE_RATE = 48000;
static constexpr size_t M17_SAMPLES_PER_SYMBOL = M17_TX_SAMPLE_RATE / M17_SYMBOL_RATE;
static constexpr size_t M17_FRAME_SAMPLES = M17_FRAME_SYMBOLS * M17_SAMPLES_PER_SYMBOL;
@ -106,7 +109,6 @@ private:
stream_sample_t *idleBuffer; ///< Half baseband buffer, free for processing.
streamId outStream; ///< Baseband output stream ID.
bool txRunning; ///< Transmission running.
bool stopTx; ///< Stop transmission request.
#if defined(PLATFORM_MD3x0) || defined(PLATFORM_MDUV3x0)
filter_state_t pwmFilterState;

56
openrtx/src/protocols/M17/M17Modulator.cpp
View File

@ -76,7 +76,6 @@ void M17::M17Modulator::start()
if(txRunning) return;
txRunning = true;
stopTx = false;
// Fill symbol buffer with preamble, made of alternated +3 and -3 symbols
for(size_t i = 0; i < symbols.size(); i += 2)
@ -112,11 +111,45 @@ void M17Modulator::send(const frame_t& frame, const bool isLast)
it = std::copy(sym.begin(), sym.end(), it);
}
symbolsToBaseband();
sendBaseband();
// If last frame, signal stop of transmission
if(isLast) stopTx = true;
if(isLast) stop();
}
void M17Modulator::stop()
{
if(txRunning == false)
return;
frame_t eotFrame;
// Fill EOT frame with 0x55, 0x5D as per M17 spec.
for(size_t i = 0; i < eotFrame.size(); i += 2)
{
eotFrame[i] = 0x55;
eotFrame[i + 1] = 0x5D;
}
// Convert to symbols
auto it = symbols.begin();
for(size_t i = 0; i < eotFrame.size(); i++)
{
auto sym = byteToSymbols(eotFrame[i]);
it = std::copy(sym.begin(), sym.end(), it);
}
symbolsToBaseband();
sendBaseband();
outputStream_stop(outStream);
outputStream_sync(outStream, false);
txRunning = false;
idleBuffer = baseband_buffer.get();
#if defined(PLATFORM_MD3x0) || defined(PLATFORM_MDUV3x0)
dsp_resetFilterState(&pwmFilterState);
#endif
}
void M17Modulator::symbolsToBaseband()
@ -148,24 +181,7 @@ void M17Modulator::sendBaseband()
// Transmission is ongoing, syncronise with stream end before proceeding
outputStream_sync(outStream, true);
// Check if transmission stop is requested, if so stop the output stream
// and wait until its effective termination.
if(stopTx == true)
{
outputStream_stop(outStream);
outputStream_sync(outStream, false);
stopTx = false;
txRunning = false;
idleBuffer = baseband_buffer.get();
#if defined(PLATFORM_MD3x0) || defined(PLATFORM_MDUV3x0)
dsp_resetFilterState(&pwmFilterState);
#endif
}
else
{
idleBuffer = outputStream_getIdleBuffer(outStream);
}
idleBuffer = outputStream_getIdleBuffer(outStream);
}
#else
void M17Modulator::sendBaseband()