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POCSAG before reformat

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This is the POCSAG code before reformat to put smooth and extract packets in the correct place
This commit is contained in:
heurist1
2021-10-10 09:15:42 +01:00
parent 848dba44d8
commit ab364ca497
9 changed files with 908 additions and 97 deletions
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140
firmware/baseband/proc_pocsag.cpp
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@@ -39,98 +39,58 @@ void POCSAGProcessor::execute(const buffer_c8_t& buffer) {
const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
auto audio = demod.execute(channel_out, audio_buffer);
//audio_output.write(audio);
smooth.Process(audio.p, audio.count); // Smooth the data to make decoding more accurate
audio_output.write(audio);
for (uint32_t c = 0; c < 16; c++) {
const int32_t sample_int = audio.p[c] * 32768.0f;
const int32_t audio_sample = __SSAT(sample_int, 16);
slicer_sr <<= 1;
if (phase == 0)
slicer_sr |= (audio_sample < 0); // Do we need hysteresis ?
processDemodulatedSamples(audio.p, 16);
extractFrames();
}
// ====================================================================
//
// ====================================================================
int POCSAGProcessor::OnDataWord(uint32_t word, int pos)
{
packet.set(pos, word);
return 0;
}
// ====================================================================
//
// ====================================================================
int POCSAGProcessor::OnDataFrame(int len, int baud)
{
if (len > 0)
{
if (baud > 492 && baud < 542)
{
bitrate = pocsag::BitRate::FSK512;
}
else if (baud > 1000 && baud < 1400)
{
bitrate = pocsag::BitRate::FSK1200;
}
else if (baud > 2300 && baud < 2500)
{
bitrate = pocsag::BitRate::FSK2400;
}
else if (baud > 3100 && baud < 3300)
{
bitrate = pocsag::BitRate::FSK3200;
}
else
slicer_sr |= !(audio_sample < 0);
// Detect transitions to adjust clock
if ((slicer_sr ^ (slicer_sr >> 1)) & 1) {
if (sphase < (0x8000u - sphase_delta_half))
sphase += sphase_delta_eighth;
else
sphase -= sphase_delta_eighth;
{
bitrate = pocsag::BitRate::UNKNOWN;
}
sphase += sphase_delta;
// Symbol time elapsed
if (sphase >= 0x10000u) {
sphase &= 0xFFFFu;
rx_data <<= 1;
rx_data |= (slicer_sr & 1);
switch (rx_state) {
case WAITING:
if (rx_data == 0xAAAAAAAA) {
rx_state = PREAMBLE;
sync_timeout = 0;
}
break;
case PREAMBLE:
if (sync_timeout < POCSAG_TIMEOUT) {
sync_timeout++;
if (rx_data == POCSAG_SYNCWORD) {
packet.clear();
codeword_count = 0;
rx_bit = 0;
msg_timeout = 0;
rx_state = SYNC;
}
} else {
// Timeout here is normal (end of message)
rx_state = WAITING;
//push_packet(pocsag::PacketFlag::TIMED_OUT);
}
break;
case SYNC:
if (msg_timeout < POCSAG_BATCH_LENGTH) {
msg_timeout++;
rx_bit++;
if (rx_bit >= 32) {
rx_bit = 0;
// Got a complete codeword
//pocsag_brute_repair(&s->l2.pocsag, &rx_data);
packet.set(codeword_count, rx_data);
if (codeword_count < 15) {
codeword_count++;
} else {
push_packet(pocsag::PacketFlag::NORMAL);
rx_state = PREAMBLE;
sync_timeout = 0;
}
}
} else {
packet.set(0, codeword_count); // Replace first codeword with count, for debug
push_packet(pocsag::PacketFlag::TIMED_OUT);
rx_state = WAITING;
}
break;
default:
break;
}
}
packet.set_bitrate(bitrate);
packet.set_flag(pocsag::PacketFlag::NORMAL);
packet.set_timestamp(Timestamp::now());
const POCSAGPacketMessage message(packet);
shared_memory.application_queue.push(message);
}
return 0;
}
void POCSAGProcessor::push_packet(pocsag::PacketFlag flag) {
@@ -162,7 +122,8 @@ void POCSAGProcessor::configure(const POCSAGConfigureMessage& message) {
decim_1.configure(taps_11k0_decim_1.taps, 131072);
channel_filter.configure(taps_11k0_channel.taps, 2);
demod.configure(demod_input_fs, 4500);
//audio_output.configure(false);
smooth.SetSize(9);
audio_output.configure(false);
bitrate = message.bitrate;
phase = message.phase;
@@ -171,6 +132,9 @@ void POCSAGProcessor::configure(const POCSAGConfigureMessage& message) {
sphase_delta_eighth = sphase_delta / 8;
rx_state = WAITING;
setParams(demod_input_fs, 6000, 300, 32);
configured = true;
}