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Merge pull request #426 from heurist1/update_pocsag_decoder
Update pocsag decoder
This commit is contained in:
Erwin Ried
GitHub
commit
0d1d703ba9
@ -30,10 +30,11 @@ using namespace pocsag;
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#include "string_format.hpp"
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#include "utility.hpp"
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#include "audio.hpp"
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void POCSAGLogger::log_raw_data(const pocsag::POCSAGPacket& packet, const uint32_t frequency) {
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std::string entry = "Raw: F:" + to_string_dec_uint(frequency) + "Hz " +
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pocsag::bitrate_str(packet.bitrate()) + " Codewords:";
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to_string_dec_uint(packet.bitrate()) + " Codewords:";
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// Raw hex dump of all the codewords
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for (size_t c = 0; c < 16; c++)
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@ -64,13 +65,13 @@ POCSAGAppView::POCSAGAppView(NavigationView& nav) {
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add_children({
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&rssi,
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&channel,
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&audio,
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&field_rf_amp,
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&field_lna,
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&field_vga,
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&field_frequency,
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&options_bitrate,
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&options_phase,
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&check_log,
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&field_volume,
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&check_ignore,
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&sym_ignore,
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&console
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@ -99,14 +100,11 @@ POCSAGAppView::POCSAGAppView(NavigationView& nav) {
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logging = v;
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};
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options_bitrate.on_change = [this](size_t, OptionsField::value_t v) {
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on_config_changed(v, options_phase.selected_index_value());
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};
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options_bitrate.set_selected_index(1); // 1200bps
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options_phase.on_change = [this](size_t, OptionsField::value_t v) {
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on_config_changed(options_bitrate.selected_index_value(),v);
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field_volume.set_value((receiver_model.headphone_volume() - audio::headphone::volume_range().max).decibel() + 99);
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field_volume.on_change = [this](int32_t v) {
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this->on_headphone_volume_changed(v);
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};
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check_ignore.set_value(ignore);
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check_ignore.on_select = [this](Checkbox&, bool v) {
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ignore = v;
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@ -121,9 +119,16 @@ POCSAGAppView::POCSAGAppView(NavigationView& nav) {
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logger = std::make_unique<POCSAGLogger>();
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if (logger)
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logger->append("pocsag.txt");
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audio::output::start();
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audio::output::unmute();
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baseband::set_pocsag();
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}
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POCSAGAppView::~POCSAGAppView() {
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audio::output::stop();
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// Save ignored address
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persistent_memory::set_pocsag_ignore_address(sym_ignore.value_dec_u32());
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@ -135,6 +140,12 @@ void POCSAGAppView::focus() {
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field_frequency.focus();
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}
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void POCSAGAppView::on_headphone_volume_changed(int32_t v) {
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const auto new_volume = volume_t::decibel(v - 99) + audio::headphone::volume_range().max;
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receiver_model.set_headphone_volume(new_volume);
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}
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// Useless ?
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void POCSAGAppView::set_parent_rect(const Rect new_parent_rect) {
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View::set_parent_rect(new_parent_rect);
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@ -154,11 +165,17 @@ void POCSAGAppView::on_packet(const POCSAGPacketMessage * message) {
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// " Ignored address " + to_string_dec_uint(pocsag_state.address));
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return;
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}
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// Too many errors for reliable decode
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if ((ignore) && (pocsag_state.errors >= 3)) {
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return;
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}
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std::string console_info;
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const uint32_t roundVal = 50;
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const uint32_t bitrate = roundVal * ((message->packet.bitrate() + (roundVal/2))/roundVal);
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console_info = "\n" + to_string_datetime(message->packet.timestamp(), HM);
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console_info += " " + pocsag::bitrate_str(message->packet.bitrate());
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console_info += " " + to_string_dec_uint(bitrate);
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console_info += " ADDR:" + to_string_dec_uint(pocsag_state.address);
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console_info += " F" + to_string_dec_uint(pocsag_state.function);
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@ -201,10 +218,6 @@ void POCSAGAppView::on_packet(const POCSAGPacketMessage * message) {
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logger->log_raw_data(message->packet, target_frequency());
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}
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void POCSAGAppView::on_config_changed(const uint32_t new_bitrate, bool new_phase) {
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baseband::set_pocsag(pocsag_bitrates[new_bitrate], new_phase);
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}
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void POCSAGAppView::set_target_frequency(const uint32_t new_value) {
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target_frequency_ = new_value;
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receiver_model.set_tuning_frequency(new_value);
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@ -61,7 +61,7 @@ private:
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static constexpr uint32_t initial_target_frequency = 466175000;
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bool logging { true };
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bool ignore { false };
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bool ignore { true };
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uint32_t last_address = 0xFFFFFFFF;
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pocsag::POCSAGState pocsag_state { };
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@ -80,49 +80,41 @@ private:
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Channel channel {
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{ 21 * 8, 5, 6 * 8, 4 },
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};
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Audio audio{
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{ 21 * 8, 10, 6 * 8, 4 },
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};
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FrequencyField field_frequency {
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{ 0 * 8, 0 * 8 },
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};
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OptionsField options_bitrate {
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{ 12 * 8, 21 },
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7,
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{
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{ "512bps ", 0 },
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{ "1200bps", 1 },
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{ "2400bps", 2 },
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{ "3200bps", 3 }
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}
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};
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OptionsField options_phase {
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{ 6 * 8, 21 },
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1,
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{
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{ "P", 0 },
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{ "N", 1 },
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}
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};
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Checkbox check_log {
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{ 22 * 8, 21 },
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{ 24 * 8, 21 },
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3,
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"LOG",
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true
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};
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NumberField field_volume{
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{ 28 * 8, 0 * 16 },
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2,
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{ 0, 99 },
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1,
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' ',
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};
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Checkbox check_ignore {
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{ 1 * 8, 40 },
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15,
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"Ignore address:",
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{ 1 * 8, 21 },
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12,
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"Ignore addr:",
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true
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};
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SymField sym_ignore {
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{ 19 * 8, 40 },
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{ 16 * 8, 21 },
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7,
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SymField::SYMFIELD_DEC
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};
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Console console {
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{ 0, 4 * 16, 240, 240 }
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{ 0, 3 * 16, 240, 256 }
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};
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std::unique_ptr<POCSAGLogger> logger { };
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@ -133,7 +125,7 @@ private:
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void on_packet(const POCSAGPacketMessage * message);
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void on_config_changed(const uint32_t new_bitrate, const bool phase);
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void on_headphone_volume_changed(int32_t v);
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uint32_t target_frequency() const;
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void set_target_frequency(const uint32_t new_value);
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@ -236,11 +236,8 @@ void set_fsk_data(const uint32_t stream_length, const uint32_t samples_per_bit,
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send_message(&message);
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}
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void set_pocsag(const pocsag::BitRate bitrate, bool phase) {
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const POCSAGConfigureMessage message {
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bitrate,
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phase
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};
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void set_pocsag() {
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const POCSAGConfigureMessage message {};
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send_message(&message);
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}
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@ -79,7 +79,7 @@ void set_ook_data(const uint32_t stream_length, const uint32_t samples_per_bit,
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const uint32_t pause_symbols);
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void set_fsk_data(const uint32_t stream_length, const uint32_t samples_per_bit, const uint32_t shift,
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const uint32_t progress_notice);
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void set_pocsag(const pocsag::BitRate bitrate, bool phase);
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void set_pocsag();
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void set_adsb();
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void set_jammer(const bool run, const jammer::JammerType type, const uint32_t speed);
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void set_rds_data(const uint16_t message_length);
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@ -28,6 +28,9 @@
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#include <cstdint>
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#include <cstddef>
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#include <algorithm> // std::max
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#include <cmath>
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void POCSAGProcessor::execute(const buffer_c8_t& buffer) {
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// This is called at 1500Hz
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@ -39,114 +42,45 @@ void POCSAGProcessor::execute(const buffer_c8_t& buffer) {
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const auto decim_1_out = decim_1.execute(decim_0_out, dst_buffer);
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const auto channel_out = channel_filter.execute(decim_1_out, dst_buffer);
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auto audio = demod.execute(channel_out, audio_buffer);
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//audio_output.write(audio);
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smooth.Process(audio.p, audio.count); // Smooth the data to make decoding more accurate
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audio_output.write(audio);
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for (uint32_t c = 0; c < 16; c++) {
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const int32_t sample_int = audio.p[c] * 32768.0f;
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const int32_t audio_sample = __SSAT(sample_int, 16);
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slicer_sr <<= 1;
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if (phase == 0)
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slicer_sr |= (audio_sample < 0); // Do we need hysteresis ?
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else
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slicer_sr |= !(audio_sample < 0);
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// Detect transitions to adjust clock
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if ((slicer_sr ^ (slicer_sr >> 1)) & 1) {
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if (sphase < (0x8000u - sphase_delta_half))
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sphase += sphase_delta_eighth;
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else
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sphase -= sphase_delta_eighth;
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}
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sphase += sphase_delta;
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// Symbol time elapsed
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if (sphase >= 0x10000u) {
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sphase &= 0xFFFFu;
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rx_data <<= 1;
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rx_data |= (slicer_sr & 1);
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switch (rx_state) {
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case WAITING:
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if (rx_data == 0xAAAAAAAA) {
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rx_state = PREAMBLE;
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sync_timeout = 0;
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}
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break;
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case PREAMBLE:
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if (sync_timeout < POCSAG_TIMEOUT) {
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sync_timeout++;
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processDemodulatedSamples(audio.p, 16);
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extractFrames();
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if (rx_data == POCSAG_SYNCWORD) {
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packet.clear();
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codeword_count = 0;
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rx_bit = 0;
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msg_timeout = 0;
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rx_state = SYNC;
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}
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} else {
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// Timeout here is normal (end of message)
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rx_state = WAITING;
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//push_packet(pocsag::PacketFlag::TIMED_OUT);
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}
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break;
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case SYNC:
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if (msg_timeout < POCSAG_BATCH_LENGTH) {
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msg_timeout++;
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rx_bit++;
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if (rx_bit >= 32) {
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rx_bit = 0;
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// Got a complete codeword
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//pocsag_brute_repair(&s->l2.pocsag, &rx_data);
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packet.set(codeword_count, rx_data);
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if (codeword_count < 15) {
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codeword_count++;
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} else {
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push_packet(pocsag::PacketFlag::NORMAL);
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rx_state = PREAMBLE;
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sync_timeout = 0;
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}
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}
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} else {
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packet.set(0, codeword_count); // Replace first codeword with count, for debug
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push_packet(pocsag::PacketFlag::TIMED_OUT);
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rx_state = WAITING;
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}
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break;
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default:
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break;
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}
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}
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}
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}
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void POCSAGProcessor::push_packet(pocsag::PacketFlag flag) {
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packet.set_bitrate(bitrate);
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packet.set_flag(flag);
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packet.set_timestamp(Timestamp::now());
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const POCSAGPacketMessage message(packet);
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shared_memory.application_queue.push(message);
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// ====================================================================
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//
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// ====================================================================
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int POCSAGProcessor::OnDataWord(uint32_t word, int pos)
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{
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packet.set(pos, word);
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return 0;
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}
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// ====================================================================
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//
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// ====================================================================
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int POCSAGProcessor::OnDataFrame(int len, int baud)
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{
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if (len > 0)
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{
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packet.set_bitrate(baud);
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packet.set_flag(pocsag::PacketFlag::NORMAL);
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packet.set_timestamp(Timestamp::now());
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const POCSAGPacketMessage message(packet);
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shared_memory.application_queue.push(message);
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}
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return 0;
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}
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void POCSAGProcessor::on_message(const Message* const message) {
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if (message->id == Message::ID::POCSAGConfigure)
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configure(*reinterpret_cast<const POCSAGConfigureMessage*>(message));
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configure();
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}
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void POCSAGProcessor::configure(const POCSAGConfigureMessage& message) {
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void POCSAGProcessor::configure() {
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constexpr size_t decim_0_input_fs = baseband_fs;
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constexpr size_t decim_0_output_fs = decim_0_input_fs / decim_0.decimation_factor;
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@ -162,18 +96,442 @@ void POCSAGProcessor::configure(const POCSAGConfigureMessage& message) {
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decim_1.configure(taps_11k0_decim_1.taps, 131072);
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channel_filter.configure(taps_11k0_channel.taps, 2);
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demod.configure(demod_input_fs, 4500);
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//audio_output.configure(false);
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// Smoothing should be roughly sample rate over max baud
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// 24k / 3.2k is 7.5
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smooth.SetSize(8);
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audio_output.configure(false);
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bitrate = message.bitrate;
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phase = message.phase;
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sphase_delta = 0x10000u * bitrate / POCSAG_AUDIO_RATE;
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sphase_delta_half = sphase_delta / 2; // Just for speed
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sphase_delta_eighth = sphase_delta / 8;
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rx_state = WAITING;
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// Set up the frame extraction, limits of baud
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setFrameExtractParams(demod_input_fs, 4000, 300, 32);
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// Mark the class as ready to accept data
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configured = true;
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}
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// -----------------------------
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// Frame extractraction methods
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// -----------------------------
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#define BAUD_STABLE (104)
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#define MAX_CONSEC_SAME (32)
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#define MAX_WITHOUT_SINGLE (64)
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#define MAX_BAD_TRANS (10)
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#define M_SYNC (0x7cd215d8)
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#define M_NOTSYNC (0x832dea27)
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#define M_IDLE (0x7a89c197)
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// ====================================================================
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//
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// ====================================================================
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inline int bitsDiff(unsigned long left, unsigned long right)
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{
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unsigned long xord = left ^ right;
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int count = 0;
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for (int i = 0; i < 32; i++)
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{
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if ((xord & 0x01) != 0) ++count;
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xord = xord >> 1;
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}
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return(count);
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}
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// ====================================================================
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//
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// ====================================================================
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void POCSAGProcessor::initFrameExtraction()
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{
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m_averageSymbolLen_1024 = m_maxSymSamples_1024;
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m_lastStableSymbolLen_1024 = m_minSymSamples_1024;
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m_badTransitions = 0;
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m_bitsStart = 0;
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m_bitsEnd = 0;
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m_inverted = false;
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resetVals();
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}
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// ====================================================================
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//
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// ====================================================================
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void POCSAGProcessor::resetVals()
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{
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// Reset the parameters
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// --------------------
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m_goodTransitions = 0;
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m_badTransitions = 0;
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m_averageSymbolLen_1024 = m_maxSymSamples_1024;
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m_shortestGoodTrans_1024 = m_maxSymSamples_1024;
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m_valMid = 0;
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// And reset the counts
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// --------------------
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m_lastTransPos_1024 = 0;
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m_lastBitPos_1024 = 0;
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m_lastSample = 0;
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m_sampleNo = 0;
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m_nextBitPos_1024 = m_maxSymSamples_1024;
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m_nextBitPosInt = (long)m_nextBitPos_1024;
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// Extraction
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m_fifo.numBits = 0;
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m_gotSync = false;
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m_numCode = 0;
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}
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// ====================================================================
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//
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// ====================================================================
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void POCSAGProcessor::setFrameExtractParams(long a_samplesPerSec, long a_maxBaud, long a_minBaud, long maxRunOfSameValue)
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{
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m_samplesPerSec = a_samplesPerSec;
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m_minSymSamples_1024 = (uint32_t)(1024.0f * (float)a_samplesPerSec / (float)a_maxBaud);
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m_maxSymSamples_1024 = (uint32_t)(1024.0f*(float)a_samplesPerSec / (float)a_minBaud);
|
||||
m_maxRunOfSameValue = maxRunOfSameValue;
|
||||
|
||||
m_shortestGoodTrans_1024 = m_maxSymSamples_1024;
|
||||
m_averageSymbolLen_1024 = m_maxSymSamples_1024;
|
||||
m_lastStableSymbolLen_1024 = m_minSymSamples_1024;
|
||||
|
||||
m_nextBitPos_1024 = m_averageSymbolLen_1024 / 2;
|
||||
m_nextBitPosInt = m_nextBitPos_1024 >> 10;
|
||||
|
||||
initFrameExtraction();
|
||||
}
|
||||
|
||||
// ====================================================================
|
||||
//
|
||||
// ====================================================================
|
||||
int POCSAGProcessor::processDemodulatedSamples(float * sampleBuff, int noOfSamples)
|
||||
{
|
||||
bool transition = false;
|
||||
uint32_t samplePos_1024 = 0;
|
||||
uint32_t len_1024 = 0;
|
||||
|
||||
// Loop through the block of data
|
||||
// ------------------------------
|
||||
for (int pos = 0; pos < noOfSamples; ++pos)
|
||||
{
|
||||
m_sample = sampleBuff[pos];
|
||||
m_valMid += (m_sample - m_valMid) / 1024.0f;
|
||||
|
||||
++m_sampleNo;
|
||||
|
||||
// Detect Transition
|
||||
// -----------------
|
||||
transition = ! ((m_lastSample < m_valMid) ^ (m_sample >= m_valMid)); // use XOR for speed
|
||||
|
||||
// If this is a transition
|
||||
// -----------------------
|
||||
if (transition)
|
||||
{
|
||||
// Calculate samples since last trans
|
||||
// ----------------------------------
|
||||
int32_t fractional_1024 = (int32_t)(((m_sample - m_valMid)*1024) / (m_sample - m_lastSample));
|
||||
if (fractional_1024 < 0) { fractional_1024 = -fractional_1024; }
|
||||
|
||||
samplePos_1024 = (m_sampleNo<<10)-fractional_1024;
|
||||
len_1024 = samplePos_1024 - m_lastTransPos_1024;
|
||||
m_lastTransPos_1024 = samplePos_1024;
|
||||
|
||||
// If symbol is large enough to be valid
|
||||
// -------------------------------------
|
||||
if (len_1024 > m_minSymSamples_1024)
|
||||
{
|
||||
// Check for shortest good transition
|
||||
// ----------------------------------
|
||||
if ((len_1024 < m_shortestGoodTrans_1024) &&
|
||||
(m_goodTransitions < BAUD_STABLE)) // detect change of symbol size
|
||||
{
|
||||
int32_t fractionOfShortest_1024 = (len_1024<<10) / m_shortestGoodTrans_1024;
|
||||
|
||||
// If currently at half the baud rate
|
||||
// ----------------------------------
|
||||
if ((fractionOfShortest_1024 > 410) && (fractionOfShortest_1024 < 614)) // 0.4 and 0.6
|
||||
{
|
||||
m_averageSymbolLen_1024 /= 2;
|
||||
m_shortestGoodTrans_1024 = len_1024;
|
||||
}
|
||||
// If currently at the wrong baud rate
|
||||
// -----------------------------------
|
||||
else if (fractionOfShortest_1024 < 768) // 0.75
|
||||
{
|
||||
m_averageSymbolLen_1024 = len_1024;
|
||||
m_shortestGoodTrans_1024 = len_1024;
|
||||
m_goodTransitions = 0;
|
||||
m_lastSingleBitPos_1024 = samplePos_1024 - len_1024;
|
||||
}
|
||||
}
|
||||
|
||||
// Calc the number of bits since events
|
||||
// ------------------------------------
|
||||
int32_t halfSymbol_1024 = m_averageSymbolLen_1024 / 2;
|
||||
int bitsSinceLastTrans = max((uint32_t)1, (len_1024+halfSymbol_1024) / m_averageSymbolLen_1024 );
|
||||
int bitsSinceLastSingle = (((m_sampleNo<<10)-m_lastSingleBitPos_1024) + halfSymbol_1024) / m_averageSymbolLen_1024;
|
||||
|
||||
// Check for single bit
|
||||
// --------------------
|
||||
if (bitsSinceLastTrans == 1)
|
||||
{
|
||||
m_lastSingleBitPos_1024 = samplePos_1024;
|
||||
}
|
||||
|
||||
// If too long since last transition
|
||||
// ---------------------------------
|
||||
if (bitsSinceLastTrans > MAX_CONSEC_SAME)
|
||||
{
|
||||
resetVals();
|
||||
}
|
||||
// If too long sice last single bit
|
||||
// --------------------------------
|
||||
else if (bitsSinceLastSingle > MAX_WITHOUT_SINGLE)
|
||||
{
|
||||
resetVals();
|
||||
}
|
||||
else
|
||||
{
|
||||
// If this is a good transition
|
||||
// ----------------------------
|
||||
int32_t offsetFromExtectedTransition_1024 = len_1024 - (bitsSinceLastTrans*m_averageSymbolLen_1024);
|
||||
if (offsetFromExtectedTransition_1024 < 0) { offsetFromExtectedTransition_1024 = -offsetFromExtectedTransition_1024; }
|
||||
if (offsetFromExtectedTransition_1024 < ((int32_t)m_averageSymbolLen_1024 / 4)) // Has to be within 1/4 of symbol to be good
|
||||
{
|
||||
++m_goodTransitions;
|
||||
uint32_t bitsCount = min((uint32_t)BAUD_STABLE, m_goodTransitions);
|
||||
|
||||
uint32_t propFromPrevious = m_averageSymbolLen_1024*bitsCount;
|
||||
uint32_t propFromCurrent = (len_1024 / bitsSinceLastTrans);
|
||||
m_averageSymbolLen_1024 = (propFromPrevious + propFromCurrent) / (bitsCount + 1);
|
||||
m_badTransitions = 0;
|
||||
//if ( len < m_shortestGoodTrans ){m_shortestGoodTrans = len;}
|
||||
// Store the old symbol size
|
||||
if (m_goodTransitions >= BAUD_STABLE)
|
||||
{
|
||||
m_lastStableSymbolLen_1024 = m_averageSymbolLen_1024;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// Set the point of the last bit if not yet stable
|
||||
// -----------------------------------------------
|
||||
if ((m_goodTransitions < BAUD_STABLE) || (m_badTransitions > 0))
|
||||
{
|
||||
m_lastBitPos_1024 = samplePos_1024 - (m_averageSymbolLen_1024 / 2);
|
||||
}
|
||||
|
||||
// Calculate the exact positiom of the next bit
|
||||
// --------------------------------------------
|
||||
int32_t thisPlusHalfsymbol_1024 = samplePos_1024 + (m_averageSymbolLen_1024/2);
|
||||
int32_t lastPlusSymbol = m_lastBitPos_1024 + m_averageSymbolLen_1024;
|
||||
m_nextBitPos_1024 = lastPlusSymbol + ((thisPlusHalfsymbol_1024 - lastPlusSymbol) / 16);
|
||||
|
||||
// Check for bad pos error
|
||||
// -----------------------
|
||||
if (m_nextBitPos_1024 < samplePos_1024) m_nextBitPos_1024 += m_averageSymbolLen_1024;
|
||||
|
||||
// Calculate integer sample after next bit
|
||||
// ---------------------------------------
|
||||
m_nextBitPosInt = (m_nextBitPos_1024>>10) + 1;
|
||||
|
||||
} // symbol is large enough to be valid
|
||||
else
|
||||
{
|
||||
// Bad transition, so reset the counts
|
||||
// -----------------------------------
|
||||
++m_badTransitions;
|
||||
if (m_badTransitions > MAX_BAD_TRANS)
|
||||
{
|
||||
resetVals();
|
||||
}
|
||||
}
|
||||
} // end of if transition
|
||||
|
||||
// Reached the point of the next bit
|
||||
// ---------------------------------
|
||||
if (m_sampleNo >= m_nextBitPosInt)
|
||||
{
|
||||
// Everything is good so extract a bit
|
||||
// -----------------------------------
|
||||
if (m_goodTransitions > 20)
|
||||
{
|
||||
// Store value at the center of bit
|
||||
// --------------------------------
|
||||
storeBit();
|
||||
}
|
||||
// Check for long 1 or zero
|
||||
// ------------------------
|
||||
uint32_t bitsSinceLastTrans = ((m_sampleNo<<10) - m_lastTransPos_1024) / m_averageSymbolLen_1024;
|
||||
if (bitsSinceLastTrans > m_maxRunOfSameValue)
|
||||
{
|
||||
resetVals();
|
||||
}
|
||||
|
||||
// Store the point of the last bit
|
||||
// -------------------------------
|
||||
m_lastBitPos_1024 = m_nextBitPos_1024;
|
||||
|
||||
// Calculate the exact point of the next bit
|
||||
// -----------------------------------------
|
||||
m_nextBitPos_1024 += m_averageSymbolLen_1024;
|
||||
|
||||
// Look for the bit after the next bit pos
|
||||
// ---------------------------------------
|
||||
m_nextBitPosInt = (m_nextBitPos_1024>>10) + 1;
|
||||
|
||||
} // Reached the point of the next bit
|
||||
|
||||
m_lastSample = m_sample;
|
||||
|
||||
} // Loop through the block of data
|
||||
|
||||
return getNoOfBits();
|
||||
}
|
||||
|
||||
// ====================================================================
|
||||
//
|
||||
// ====================================================================
|
||||
void POCSAGProcessor::storeBit()
|
||||
{
|
||||
if (++m_bitsStart >= BIT_BUF_SIZE) { m_bitsStart = 0; }
|
||||
|
||||
// Calculate the bit value
|
||||
float sample = (m_sample + m_lastSample) / 2;
|
||||
//int32_t sample_1024 = m_sample_1024;
|
||||
bool bit = sample > m_valMid;
|
||||
|
||||
// If buffer not full
|
||||
if (m_bitsStart != m_bitsEnd)
|
||||
{
|
||||
// Decide on output val
|
||||
if (bit)
|
||||
{
|
||||
m_bits[m_bitsStart] = 0;
|
||||
}
|
||||
else
|
||||
{
|
||||
m_bits[m_bitsStart] = 1;
|
||||
}
|
||||
}
|
||||
// Throw away bits if the buffer is full
|
||||
else
|
||||
{
|
||||
if (--m_bitsStart <= -1)
|
||||
{
|
||||
m_bitsStart = BIT_BUF_SIZE - 1;
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// ====================================================================
|
||||
//
|
||||
// ====================================================================
|
||||
int POCSAGProcessor::extractFrames()
|
||||
{
|
||||
int msgCnt = 0;
|
||||
// While there is unread data in the bits buffer
|
||||
//----------------------------------------------
|
||||
while (getNoOfBits() > 0)
|
||||
{
|
||||
m_fifo.codeword = (m_fifo.codeword << 1) + getBit();
|
||||
m_fifo.numBits++;
|
||||
|
||||
// If number of bits in fifo equals 32
|
||||
//------------------------------------
|
||||
if (m_fifo.numBits >= 32)
|
||||
{
|
||||
// Not got sync
|
||||
// ------------
|
||||
if (!m_gotSync)
|
||||
{
|
||||
if (bitsDiff(m_fifo.codeword, M_SYNC) <= 2)
|
||||
{
|
||||
m_inverted = false;
|
||||
m_gotSync = true;
|
||||
m_numCode = -1;
|
||||
m_fifo.numBits = 0;
|
||||
}
|
||||
else if (bitsDiff(m_fifo.codeword, M_NOTSYNC) <= 2)
|
||||
{
|
||||
m_inverted = true;
|
||||
m_gotSync = true;
|
||||
m_numCode = -1;
|
||||
m_fifo.numBits = 0;
|
||||
}
|
||||
else
|
||||
{
|
||||
// Cause it to load one more bit
|
||||
m_fifo.numBits = 31;
|
||||
}
|
||||
} // Not got sync
|
||||
else
|
||||
{
|
||||
// Increment the word count
|
||||
// ------------------------
|
||||
++m_numCode; // It got set to -1 when a sync was found, now count the 16 words
|
||||
uint32_t val = m_inverted ? ~m_fifo.codeword : m_fifo.codeword;
|
||||
OnDataWord(val, m_numCode);
|
||||
|
||||
// If at the end of a 16 word block
|
||||
// --------------------------------
|
||||
if (m_numCode >= 15)
|
||||
{
|
||||
msgCnt += OnDataFrame(m_numCode+1, (m_samplesPerSec<<10) / m_lastStableSymbolLen_1024);
|
||||
m_gotSync = false;
|
||||
m_numCode = -1;
|
||||
}
|
||||
m_fifo.numBits = 0;
|
||||
}
|
||||
} // If number of bits in fifo equals 32
|
||||
} // While there is unread data in the bits buffer
|
||||
return msgCnt;
|
||||
} // extractFrames
|
||||
|
||||
// ====================================================================
|
||||
//
|
||||
// ====================================================================
|
||||
short POCSAGProcessor::getBit()
|
||||
{
|
||||
if (m_bitsEnd != m_bitsStart)
|
||||
{
|
||||
if (++m_bitsEnd >= BIT_BUF_SIZE)
|
||||
{
|
||||
m_bitsEnd = 0;
|
||||
}
|
||||
return m_bits[m_bitsEnd];
|
||||
}
|
||||
else
|
||||
{
|
||||
return -1;
|
||||
}
|
||||
}
|
||||
|
||||
// ====================================================================
|
||||
//
|
||||
// ====================================================================
|
||||
int POCSAGProcessor::getNoOfBits()
|
||||
{
|
||||
int bits = m_bitsEnd - m_bitsStart;
|
||||
if (bits < 0) { bits += BIT_BUF_SIZE; }
|
||||
return bits;
|
||||
}
|
||||
|
||||
// ====================================================================
|
||||
//
|
||||
// ====================================================================
|
||||
uint32_t POCSAGProcessor::getRate()
|
||||
{
|
||||
return ((m_samplesPerSec<<10)+512) / m_lastStableSymbolLen_1024;
|
||||
}
|
||||
|
||||
|
||||
// ====================================================================
|
||||
//
|
||||
// ====================================================================
|
||||
int main() {
|
||||
EventDispatcher event_dispatcher { std::make_unique<POCSAGProcessor>() };
|
||||
event_dispatcher.run();
|
||||
|
||||
@ -40,25 +40,100 @@
|
||||
#include "portapack_shared_memory.hpp"
|
||||
|
||||
#include <cstdint>
|
||||
#include <bitset>
|
||||
using namespace std;
|
||||
|
||||
// Class used to smooth demodulated waveform prior to decoding
|
||||
// -----------------------------------------------------------
|
||||
template <class ValType, class CalcType>
|
||||
class SmoothVals
|
||||
{
|
||||
protected:
|
||||
ValType * m_lastVals; // Previoius N values
|
||||
int m_size; // The size N
|
||||
CalcType m_sumVal; // Running sum of lastVals
|
||||
int m_pos; // Current position in last vals ring buffer
|
||||
int m_count; //
|
||||
|
||||
class POCSAGProcessor : public BasebandProcessor {
|
||||
public:
|
||||
SmoothVals() : m_lastVals(NULL), m_size(1), m_sumVal(0), m_pos(0), m_count(0)
|
||||
{
|
||||
m_lastVals = new ValType[m_size];
|
||||
}
|
||||
|
||||
// --------------------------------------------------
|
||||
// --------------------------------------------------
|
||||
virtual ~SmoothVals()
|
||||
{
|
||||
delete[] m_lastVals;
|
||||
}
|
||||
|
||||
// --------------------------------------------------
|
||||
// Set size of smoothing
|
||||
// --------------------------------------------------
|
||||
void SetSize(int size)
|
||||
{
|
||||
m_size = std::max(size, 1);
|
||||
m_pos = 0;
|
||||
delete[] m_lastVals;
|
||||
m_lastVals = new ValType[m_size];
|
||||
m_sumVal = 0;
|
||||
}
|
||||
|
||||
// --------------------------------------------------
|
||||
// Get size of smoothing
|
||||
// --------------------------------------------------
|
||||
int Size() { return m_size; }
|
||||
|
||||
// --------------------------------------------------
|
||||
// In place processing
|
||||
// --------------------------------------------------
|
||||
void Process(ValType * valBuff, int numVals)
|
||||
{
|
||||
ValType tmpVal;
|
||||
|
||||
if (m_count > (1024*10))
|
||||
{
|
||||
// Recalculate the sum value occasionaly, stops accumulated errors when using float
|
||||
m_count = 0;
|
||||
m_sumVal = 0;
|
||||
for (int i = 0; i < m_size; ++i) { m_sumVal += (CalcType)m_lastVals[i]; }
|
||||
}
|
||||
|
||||
// Use a rolling smoothed value while processing the buffer
|
||||
for (int buffPos = 0; buffPos < numVals; ++buffPos)
|
||||
{
|
||||
m_pos = (m_pos + 1); // Increment the position in the stored values
|
||||
if (m_pos >= m_size) { m_pos = 0; } // loop if reached the end of the stored values
|
||||
|
||||
m_sumVal -= (CalcType)m_lastVals[m_pos]; // Subtract the oldest value
|
||||
m_lastVals[m_pos] = valBuff[buffPos]; // Store the new value
|
||||
m_sumVal += (CalcType)m_lastVals[m_pos]; // Add on the new value
|
||||
|
||||
tmpVal = (ValType)(m_sumVal / m_size); // Scale by number of values smoothed
|
||||
valBuff[buffPos] = tmpVal;
|
||||
}
|
||||
|
||||
m_count += numVals;
|
||||
}
|
||||
};
|
||||
|
||||
|
||||
|
||||
// --------------------------------------------------
|
||||
// Class to process base band data to pocsag frames
|
||||
// --------------------------------------------------
|
||||
class POCSAGProcessor : public BasebandProcessor{
|
||||
public:
|
||||
|
||||
void execute(const buffer_c8_t& buffer) override;
|
||||
|
||||
void on_message(const Message* const message) override;
|
||||
|
||||
private:
|
||||
enum rx_states {
|
||||
WAITING = 0,
|
||||
PREAMBLE = 32,
|
||||
SYNC = 64,
|
||||
//LOSING_SYNC = 65,
|
||||
//LOST_SYNC = 66,
|
||||
//ADDRESS = 67,
|
||||
//MESSAGE = 68,
|
||||
//END_OF_MESSAGE = 69
|
||||
};
|
||||
int OnDataFrame(int len, int baud);
|
||||
int OnDataWord(uint32_t word, int pos);
|
||||
|
||||
private:
|
||||
static constexpr size_t baseband_fs = 3072000;
|
||||
|
||||
BasebandThread baseband_thread { baseband_fs, this, NORMALPRIO + 20, baseband::Direction::Receive };
|
||||
@ -79,28 +154,71 @@ private:
|
||||
dsp::decimate::FIRC16xR16x32Decim8 decim_1 { };
|
||||
dsp::decimate::FIRAndDecimateComplex channel_filter { };
|
||||
dsp::demodulate::FM demod { };
|
||||
SmoothVals<float, float> smooth;
|
||||
|
||||
//AudioOutput audio_output { };
|
||||
AudioOutput audio_output { };
|
||||
|
||||
uint32_t sync_timeout { 0 };
|
||||
uint32_t msg_timeout { 0 };
|
||||
|
||||
uint32_t slicer_sr { 0 };
|
||||
uint32_t sphase { 0 };
|
||||
uint32_t sphase_delta { 0 };
|
||||
uint32_t sphase_delta_half { 0 };
|
||||
uint32_t sphase_delta_eighth { 0 };
|
||||
uint32_t rx_data { 0 };
|
||||
uint32_t rx_bit { 0 };
|
||||
bool configured = false;
|
||||
rx_states rx_state { WAITING };
|
||||
pocsag::BitRate bitrate { pocsag::BitRate::FSK1200 };
|
||||
bool phase = false ;
|
||||
uint32_t codeword_count { 0 };
|
||||
pocsag::POCSAGPacket packet { };
|
||||
|
||||
void push_packet(pocsag::PacketFlag flag);
|
||||
void configure(const POCSAGConfigureMessage& message);
|
||||
|
||||
void configure();
|
||||
|
||||
// ----------------------------------------
|
||||
// Frame extractraction methods and members
|
||||
// ----------------------------------------
|
||||
private:
|
||||
void initFrameExtraction();
|
||||
struct FIFOStruct {
|
||||
unsigned long codeword;
|
||||
int numBits;
|
||||
};
|
||||
|
||||
#define BIT_BUF_SIZE (64)
|
||||
|
||||
void resetVals();
|
||||
void setFrameExtractParams(long a_samplesPerSec, long a_maxBaud = 8000, long a_minBaud = 200, long maxRunOfSameValue = 32);
|
||||
|
||||
int processDemodulatedSamples(float * sampleBuff, int noOfSamples);
|
||||
int extractFrames();
|
||||
|
||||
void storeBit();
|
||||
short getBit();
|
||||
|
||||
int getNoOfBits();
|
||||
uint32_t getRate();
|
||||
|
||||
uint32_t m_averageSymbolLen_1024{0};
|
||||
uint32_t m_lastStableSymbolLen_1024{0};
|
||||
|
||||
uint32_t m_samplesPerSec{0};
|
||||
uint32_t m_goodTransitions{0};
|
||||
uint32_t m_badTransitions{0};
|
||||
|
||||
uint32_t m_sampleNo{0};
|
||||
float m_sample{0};
|
||||
float m_valMid{0.0f};
|
||||
float m_lastSample{0.0f};
|
||||
|
||||
uint32_t m_lastTransPos_1024{0};
|
||||
uint32_t m_lastSingleBitPos_1024{0};
|
||||
|
||||
uint32_t m_nextBitPosInt{0}; // Integer rounded up version to save on ops
|
||||
uint32_t m_nextBitPos_1024{0};
|
||||
uint32_t m_lastBitPos_1024{0};
|
||||
|
||||
uint32_t m_shortestGoodTrans_1024{0};
|
||||
uint32_t m_minSymSamples_1024{0};
|
||||
uint32_t m_maxSymSamples_1024{0};
|
||||
uint32_t m_maxRunOfSameValue{0};
|
||||
|
||||
bitset<(size_t)BIT_BUF_SIZE> m_bits{0};
|
||||
long m_bitsStart{0};
|
||||
long m_bitsEnd{0};
|
||||
|
||||
FIFOStruct m_fifo{0,0};
|
||||
bool m_gotSync{false};
|
||||
int m_numCode{0};
|
||||
bool m_inverted{false};
|
||||
|
||||
};
|
||||
|
||||
|
||||
@ -1019,17 +1019,10 @@ public:
|
||||
|
||||
class POCSAGConfigureMessage : public Message {
|
||||
public:
|
||||
constexpr POCSAGConfigureMessage(
|
||||
const pocsag::BitRate bitrate,
|
||||
const bool phase
|
||||
) : Message { ID::POCSAGConfigure },
|
||||
bitrate(bitrate),
|
||||
phase(phase)
|
||||
constexpr POCSAGConfigureMessage()
|
||||
: Message { ID::POCSAGConfigure }
|
||||
{
|
||||
}
|
||||
|
||||
const pocsag::BitRate bitrate;
|
||||
const bool phase;
|
||||
};
|
||||
|
||||
class APRSPacketMessage : public Message {
|
||||
|
||||
@ -36,6 +36,7 @@ std::string bitrate_str(BitRate bitrate) {
|
||||
case BitRate::FSK512: return "512bps ";
|
||||
case BitRate::FSK1200: return "1200bps";
|
||||
case BitRate::FSK2400: return "2400bps";
|
||||
case BitRate::FSK3200: return "3200bps";
|
||||
default: return "????";
|
||||
}
|
||||
}
|
||||
@ -219,7 +220,176 @@ void pocsag_encode(const MessageType type, BCHCode& BCH_code, const uint32_t fun
|
||||
} while (char_idx < message_size);
|
||||
}
|
||||
|
||||
|
||||
// -------------------------------------------------------------------------------
|
||||
// -------------------------------------------------------------------------------
|
||||
inline int bitsDiff(unsigned long left, unsigned long right)
|
||||
{
|
||||
unsigned long xord = left ^ right;
|
||||
int count = 0;
|
||||
for (int i = 0; i<32; i++)
|
||||
{
|
||||
if ((xord & 0x01) != 0) ++count;
|
||||
xord = xord >> 1;
|
||||
}
|
||||
return(count);
|
||||
|
||||
}
|
||||
|
||||
// -------------------------------------------------------------------------------
|
||||
// -------------------------------------------------------------------------------
|
||||
static uint32_t ecs[32]; /* error correction sequence */
|
||||
static uint32_t bch[1025];
|
||||
static int eccSetup = 0;
|
||||
|
||||
// -------------------------------------------------------------------------------
|
||||
// -------------------------------------------------------------------------------
|
||||
void setupecc()
|
||||
{
|
||||
unsigned int srr = 0x3b4;
|
||||
unsigned int i, n, j, k;
|
||||
|
||||
/* calculate all information needed to implement error correction */
|
||||
// Note : this is only for 31,21 code used in pocsag & flex
|
||||
// one should probably also make use of 32nd parity bit
|
||||
for (i = 0; i <= 20; i++)
|
||||
{
|
||||
ecs[i] = srr;
|
||||
if ((srr & 0x01) != 0) srr = (srr >> 1) ^ 0x3B4; else srr = srr >> 1;
|
||||
}
|
||||
|
||||
/* bch holds a syndrome look-up table telling which bits to correct */
|
||||
// first 5 bits hold location of first error; next 5 bits hold location
|
||||
// of second error; bits 12 & 13 tell how many bits are bad
|
||||
for (i = 0; i<1024; i++) bch[i] = 0;
|
||||
|
||||
/* two errors in data */
|
||||
for (n = 0; n <= 20; n++)
|
||||
{
|
||||
for (i = 0; i <= 20; i++)
|
||||
{
|
||||
j = (i << 5) + n;
|
||||
k = ecs[n] ^ ecs[i];
|
||||
bch[k] = j + 0x2000;
|
||||
}
|
||||
}
|
||||
|
||||
/* one error in data */
|
||||
for (n = 0; n <= 20; n++)
|
||||
{
|
||||
k = ecs[n];
|
||||
j = n + (0x1f << 5);
|
||||
bch[k] = j + 0x1000;
|
||||
}
|
||||
|
||||
/* one error in data and one error in ecc portion */
|
||||
for (n = 0; n <= 20; n++)
|
||||
{
|
||||
for (i = 0; i<10; i++) /* ecc screwed up bit */
|
||||
{
|
||||
k = ecs[n] ^ (1 << i);
|
||||
j = n + (0x1f << 5);
|
||||
bch[k] = j + 0x2000;
|
||||
}
|
||||
}
|
||||
|
||||
/* one error in ecc */
|
||||
for (n = 0; n<10; n++)
|
||||
{
|
||||
k = 1 << n;
|
||||
bch[k] = 0x3ff + 0x1000;
|
||||
}
|
||||
|
||||
/* two errors in ecc */
|
||||
for (n = 0; n<10; n++)
|
||||
{
|
||||
for (i = 0; i<10; i++)
|
||||
{
|
||||
if (i != n)
|
||||
{
|
||||
k = (1 << n) ^ (1 << i);
|
||||
bch[k] = 0x3ff + 0x2000;
|
||||
}
|
||||
}
|
||||
}
|
||||
}
|
||||
|
||||
// -------------------------------------------------------------------------------
|
||||
// -------------------------------------------------------------------------------
|
||||
inline int errorCorrection(uint32_t * val)
|
||||
{
|
||||
// Set up the tables the first time
|
||||
if (eccSetup == 0)
|
||||
{
|
||||
setupecc();
|
||||
eccSetup = 1;
|
||||
}
|
||||
|
||||
int i, synd, errl, acc, pari, ecc, b1, b2;
|
||||
|
||||
errl = 0;
|
||||
pari = 0;
|
||||
|
||||
/* run through error detection and correction routine */
|
||||
|
||||
// for (i=0; i<=20; i++)
|
||||
ecc = 0;
|
||||
for (i = 31; i >= 11; --i)
|
||||
{
|
||||
if ((*val&(1 << i))) { ecc = ecc ^ ecs[31 - i]; pari = pari ^ 0x01; }
|
||||
}
|
||||
|
||||
// for (i=21; i<=30; i++)
|
||||
acc = 0;
|
||||
for (i = 10; i >= 1; --i)
|
||||
{
|
||||
acc = acc << 1;
|
||||
if ((*val&(1 << i))) { acc = acc ^ 0x01; }
|
||||
}
|
||||
|
||||
synd = ecc ^ acc;
|
||||
|
||||
errl = 0;
|
||||
|
||||
if (synd != 0) /* if nonzero syndrome we have error */
|
||||
{
|
||||
|
||||
if (bch[synd] != 0) /* check for correctable error */
|
||||
{
|
||||
b1 = bch[synd] & 0x1f;
|
||||
b2 = bch[synd] >> 5;
|
||||
b2 = b2 & 0x1f;
|
||||
|
||||
if (b2 != 0x1f)
|
||||
{
|
||||
*val ^= 0x01 << (31 - b2);
|
||||
ecc = ecc ^ ecs[b2];
|
||||
}
|
||||
|
||||
if (b1 != 0x1f)
|
||||
{
|
||||
*val ^= 0x01 << (31 - b1);
|
||||
ecc = ecc ^ ecs[b1];
|
||||
}
|
||||
|
||||
errl = bch[synd] >> 12;
|
||||
}
|
||||
else
|
||||
{
|
||||
errl = 3;
|
||||
}
|
||||
|
||||
if (errl == 1) pari = pari ^ 0x01;
|
||||
}
|
||||
|
||||
if (errl == 4) errl = 3;
|
||||
|
||||
return errl;
|
||||
}
|
||||
|
||||
|
||||
void pocsag_decode_batch(const POCSAGPacket& batch, POCSAGState * const state) {
|
||||
int errors = 0;
|
||||
uint32_t codeword;
|
||||
char ascii_char;
|
||||
std::string output_text = "";
|
||||
@ -230,15 +400,21 @@ void pocsag_decode_batch(const POCSAGPacket& batch, POCSAGState * const state) {
|
||||
for (size_t i = 0; i < 16; i++) {
|
||||
codeword = batch[i];
|
||||
|
||||
errorCorrection(&codeword);
|
||||
errors = errorCorrection(&codeword);
|
||||
|
||||
if (!(codeword & 0x80000000U)) {
|
||||
// Address codeword
|
||||
if (state->mode == STATE_CLEAR) {
|
||||
if (codeword != POCSAG_IDLEWORD) {
|
||||
//if (codeword != POCSAG_IDLEWORD) {
|
||||
if (! (bitsDiff(codeword, POCSAG_IDLEWORD) < 1)){
|
||||
|
||||
state->function = (codeword >> 11) & 3;
|
||||
state->address = (codeword >> 10) & 0x1FFFF8U; // 18 MSBs are transmitted
|
||||
state->mode = STATE_HAVE_ADDRESS;
|
||||
state->out_type = ADDRESS;
|
||||
|
||||
state->errors = errors;
|
||||
|
||||
state->ascii_idx = 0;
|
||||
state->ascii_data = 0;
|
||||
}
|
||||
@ -246,6 +422,7 @@ void pocsag_decode_batch(const POCSAGPacket& batch, POCSAGState * const state) {
|
||||
state->mode = STATE_CLEAR; // New address = new message
|
||||
}
|
||||
} else {
|
||||
state->errors += errors;
|
||||
// Message codeword
|
||||
if (state->mode == STATE_HAVE_ADDRESS) {
|
||||
// First message codeword: complete address
|
||||
@ -270,7 +447,10 @@ void pocsag_decode_batch(const POCSAGPacket& batch, POCSAGState * const state) {
|
||||
|
||||
// Translate non-printable chars
|
||||
if ((ascii_char < 32) || (ascii_char > 126))
|
||||
output_text += "[" + to_string_dec_uint(ascii_char) + "]";
|
||||
{
|
||||
//output_text += "[" + to_string_dec_uint(ascii_char) + "]";
|
||||
output_text += ".";
|
||||
}
|
||||
else
|
||||
output_text += ascii_char;
|
||||
}
|
||||
|
||||
@ -62,6 +62,7 @@ struct POCSAGState {
|
||||
OutputType out_type = EMPTY;
|
||||
uint32_t ascii_data;
|
||||
uint32_t ascii_idx;
|
||||
uint32_t errors;
|
||||
std::string output;
|
||||
};
|
||||
|
||||
|
||||
@ -63,11 +63,11 @@ public:
|
||||
return (index < 16) ? codewords[index] : 0;
|
||||
}
|
||||
|
||||
void set_bitrate(const BitRate bitrate) {
|
||||
void set_bitrate(const uint16_t bitrate) {
|
||||
bitrate_ = bitrate;
|
||||
}
|
||||
|
||||
BitRate bitrate() const {
|
||||
uint16_t bitrate() const {
|
||||
return bitrate_;
|
||||
}
|
||||
|
||||
@ -81,12 +81,12 @@ public:
|
||||
|
||||
void clear() {
|
||||
codewords.fill(0);
|
||||
bitrate_ = UNKNOWN;
|
||||
bitrate_ = 0u;
|
||||
flag_ = NORMAL;
|
||||
}
|
||||
|
||||
private:
|
||||
BitRate bitrate_ { UNKNOWN };
|
||||
uint16_t bitrate_ { 0 };
|
||||
PacketFlag flag_ { NORMAL };
|
||||
std::array <uint32_t, 16> codewords { 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 , 0 };
|
||||
Timestamp timestamp_ { };
|
||||
|
||||
Loading…
Reference in New Issue
Block a user