mayhem-firmware/firmware/baseband/main.cpp

771 lines
20 KiB
C++
Executable File

/*
* Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
*
* This file is part of PortaPack.
*
* This program is free software; you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation; either version 2, or (at your option)
* any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program; see the file COPYING. If not, write to
* the Free Software Foundation, Inc., 51 Franklin Street,
* Boston, MA 02110-1301, USA.
*/
#include "ch.h"
#include "test.h"
#include "lpc43xx_cpp.hpp"
#include "portapack_shared_memory.hpp"
#include "portapack_dma.hpp"
#include "gpdma.hpp"
#include "baseband_dma.hpp"
#include "event_m4.hpp"
#include "irq_ipc_m4.hpp"
#include "rssi.hpp"
#include "rssi_dma.hpp"
#include "touch_dma.hpp"
#include "dsp_decimate.hpp"
#include "dsp_demodulate.hpp"
#include "dsp_fft.hpp"
#include "dsp_fir_taps.hpp"
#include "dsp_iir.hpp"
#include "dsp_iir_config.hpp"
#include "baseband_stats_collector.hpp"
#include "rssi_stats_collector.hpp"
#include "channel_stats_collector.hpp"
#include "audio_stats_collector.hpp"
#include "channel_decimator.hpp"
#include "block_decimator.hpp"
#include "clock_recovery.hpp"
#include "access_code_correlator.hpp"
#include "packet_builder.hpp"
#include "message_queue.hpp"
#include "utility.hpp"
#include "debug.hpp"
#include "audio.hpp"
#include "audio_dma.hpp"
#include "gcc.hpp"
#include <cstdint>
#include <cstddef>
#include <array>
#include <string>
#include <bitset>
constexpr auto baseband_thread_priority = NORMALPRIO + 20;
constexpr auto rssi_thread_priority = NORMALPRIO + 10;
class FMSquelch {
public:
bool execute(buffer_s16_t audio) {
// TODO: No hard-coded array size.
std::array<int16_t, N> squelch_energy_buffer;
const buffer_s16_t squelch_energy {
squelch_energy_buffer.data(),
squelch_energy_buffer.size()
};
non_audio_hpf.execute(audio, squelch_energy);
uint64_t max_squared = 0;
for(const auto sample : squelch_energy_buffer) {
const uint64_t sample_squared = sample * sample;
if( sample_squared > max_squared ) {
max_squared = sample_squared;
}
}
return (max_squared < (threshold * threshold));
}
private:
static constexpr size_t N = 32;
static constexpr int16_t threshold = 3072;
// nyquist = 48000 / 2.0
// scipy.signal.iirdesign(wp=8000 / nyquist, ws= 4000 / nyquist, gpass=1, gstop=18, ftype='ellip')
IIRBiquadFilter non_audio_hpf { non_audio_hpf_config };
};
static volatile bool channel_spectrum_request_update { false };
static std::array<complex16_t, 256> channel_spectrum;
static uint32_t channel_spectrum_sampling_rate { 0 };
static uint32_t channel_filter_pass_frequency { 0 };
static uint32_t channel_filter_stop_frequency { 0 };
class BasebandProcessor {
public:
virtual ~BasebandProcessor() = default;
virtual void execute(buffer_c8_t buffer) = 0;
protected:
void feed_channel_stats(const buffer_c16_t channel) {
channel_stats.feed(
channel,
[this](const ChannelStatistics statistics) {
this->post_channel_stats_message(statistics);
}
);
}
void feed_channel_spectrum(
const buffer_c16_t channel,
const uint32_t filter_pass_frequency,
const uint32_t filter_stop_frequency
) {
channel_filter_pass_frequency = filter_pass_frequency;
channel_filter_stop_frequency = filter_stop_frequency;
channel_spectrum_decimator.feed(
channel,
[this](const buffer_c16_t data) {
this->post_channel_spectrum_message(data);
}
);
}
void fill_audio_buffer(const buffer_s16_t audio) {
auto audio_buffer = audio::dma::tx_empty_buffer();;
for(size_t i=0; i<audio_buffer.count; i++) {
audio_buffer.p[i].left = audio_buffer.p[i].right = audio.p[i];
}
i2s::i2s0::tx_unmute();
feed_audio_stats(audio);
}
private:
BlockDecimator<256> channel_spectrum_decimator { 4 };
ChannelStatsCollector channel_stats;
ChannelStatisticsMessage channel_stats_message;
AudioStatsCollector audio_stats;
AudioStatisticsMessage audio_stats_message;
void post_channel_stats_message(const ChannelStatistics statistics) {
channel_stats_message.statistics = statistics;
shared_memory.application_queue.push(channel_stats_message);
}
void post_channel_spectrum_message(const buffer_c16_t data) {
if( !channel_spectrum_request_update ) {
channel_spectrum_request_update = true;
std::copy(&data.p[0], &data.p[data.count], channel_spectrum.begin());
channel_spectrum_sampling_rate = data.sampling_rate;
events_flag(EVT_MASK_SPECTRUM);
}
}
void feed_audio_stats(const buffer_s16_t audio) {
audio_stats.feed(
audio,
[this](const AudioStatistics statistics) {
this->post_audio_stats_message(statistics);
}
);
}
void post_audio_stats_message(const AudioStatistics statistics) {
audio_stats_message.statistics = statistics;
shared_memory.application_queue.push(audio_stats_message);
}
};
class NarrowbandAMAudio : public BasebandProcessor {
public:
void execute(buffer_c8_t buffer) override {
auto decimator_out = decimator.execute(buffer);
const buffer_c16_t work_baseband_buffer {
(complex16_t*)decimator_out.p,
sizeof(*decimator_out.p) * decimator_out.count
};
/* 96kHz complex<int16_t>[64]
* -> FIR filter, <?kHz (0.???fs) pass, gain 1.0
* -> 48kHz int16_t[32] */
auto channel = channel_filter.execute(decimator_out, work_baseband_buffer);
// TODO: Feed channel_stats post-decimation data?
feed_channel_stats(channel);
feed_channel_spectrum(
channel,
decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized,
decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized
);
const buffer_s16_t work_audio_buffer {
(int16_t*)decimator_out.p,
sizeof(*decimator_out.p) * decimator_out.count
};
/* 48kHz complex<int16_t>[32]
* -> AM demodulation
* -> 48kHz int16_t[32] */
auto audio = demod.execute(channel, work_audio_buffer);
audio_hpf.execute_in_place(audio);
fill_audio_buffer(audio);
}
private:
ChannelDecimator decimator { ChannelDecimator::DecimationFactor::By32 };
const fir_taps_real<64>& channel_filter_taps = taps_64_lp_031_070_tfilter;
dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { channel_filter_taps.taps };
dsp::demodulate::AM demod;
IIRBiquadFilter audio_hpf { audio_hpf_config };
};
class NarrowbandFMAudio : public BasebandProcessor {
public:
void execute(buffer_c8_t buffer) override {
/* Called every 2048/3072000 second -- 1500Hz. */
auto decimator_out = decimator.execute(buffer);
const buffer_c16_t work_baseband_buffer {
(complex16_t*)decimator_out.p,
sizeof(*decimator_out.p) * decimator_out.count
};
/* 96kHz complex<int16_t>[64]
* -> FIR filter, <6kHz (0.063fs) pass, gain 1.0
* -> 48kHz int16_t[32] */
auto channel = channel_filter.execute(decimator_out, work_baseband_buffer);
// TODO: Feed channel_stats post-decimation data?
feed_channel_stats(channel);
feed_channel_spectrum(
channel,
decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized,
decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized
);
const buffer_s16_t work_audio_buffer {
(int16_t*)decimator_out.p,
sizeof(*decimator_out.p) * decimator_out.count
};
/* 48kHz complex<int16_t>[32]
* -> FM demodulation
* -> 48kHz int16_t[32] */
auto audio = demod.execute(channel, work_audio_buffer);
static uint64_t audio_present_history = 0;
const auto audio_present_now = squelch.execute(audio);
audio_present_history = (audio_present_history << 1) | (audio_present_now ? 1 : 0);
const bool audio_present = (audio_present_history != 0);
if( !audio_present ) {
// Zero audio buffer.
for(size_t i=0; i<audio.count; i++) {
audio.p[i] = 0;
}
}
audio_hpf.execute_in_place(audio);
fill_audio_buffer(audio);
}
private:
ChannelDecimator decimator { ChannelDecimator::DecimationFactor::By32 };
const fir_taps_real<64>& channel_filter_taps = taps_64_lp_042_078_tfilter;
dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { channel_filter_taps.taps };
dsp::demodulate::FM demod { 48000, 7500 };
IIRBiquadFilter audio_hpf { audio_hpf_config };
FMSquelch squelch;
};
class WidebandFMAudio : public BasebandProcessor {
public:
void execute(buffer_c8_t buffer) override {
auto decimator_out = decimator.execute(buffer);
const buffer_s16_t work_audio_buffer {
(int16_t*)decimator_out.p,
sizeof(*decimator_out.p) * decimator_out.count
};
auto channel = decimator_out;
// TODO: Feed channel_stats post-decimation data?
feed_channel_stats(channel);
//feed_channel_spectrum(channel);
/* 768kHz complex<int16_t>[512]
* -> FM demodulation
* -> 768kHz int16_t[512] */
/* TODO: To improve adjacent channel rejection, implement complex channel filter:
* pass < +/- 100kHz, stop > +/- 200kHz
*/
auto audio_oversampled = demod.execute(decimator_out, work_audio_buffer);
/* 768kHz int16_t[512]
* -> 4th order CIC decimation by 2, gain of 1
* -> 384kHz int16_t[256] */
auto audio_8fs = audio_dec_1.execute(audio_oversampled, work_audio_buffer);
/* 384kHz int16_t[256]
* -> 4th order CIC decimation by 2, gain of 1
* -> 192kHz int16_t[128] */
auto audio_4fs = audio_dec_2.execute(audio_8fs, work_audio_buffer);
/* 192kHz int16_t[128]
* -> 4th order CIC decimation by 2, gain of 1
* -> 96kHz int16_t[64] */
auto audio_2fs = audio_dec_3.execute(audio_4fs, work_audio_buffer);
/* 96kHz int16_t[64]
* -> FIR filter, <15kHz (0.156fs) pass, >19kHz (0.198fs) stop, gain of 1
* -> 48kHz int16_t[32] */
auto audio = audio_filter.execute(audio_2fs, work_audio_buffer);
/* -> 48kHz int16_t[32] */
audio_hpf.execute_in_place(audio);
fill_audio_buffer(audio);
}
private:
ChannelDecimator decimator { ChannelDecimator::DecimationFactor::By4 };
//dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { taps_64_lp_031_070_tfilter };
dsp::demodulate::FM demod { 768000, 75000 };
dsp::decimate::DecimateBy2CIC4Real audio_dec_1;
dsp::decimate::DecimateBy2CIC4Real audio_dec_2;
dsp::decimate::DecimateBy2CIC4Real audio_dec_3;
const fir_taps_real<64>& audio_filter_taps = taps_64_lp_156_198;
dsp::decimate::FIR64AndDecimateBy2Real audio_filter { audio_filter_taps.taps };
IIRBiquadFilter audio_hpf { audio_hpf_config };
};
class FSKProcessor : public BasebandProcessor {
public:
FSKProcessor(
MessageHandlerMap& message_handlers
) : message_handlers(message_handlers)
{
message_handlers.register_handler(Message::ID::FSKConfiguration,
[this](const Message* const p) {
auto m = reinterpret_cast<const FSKConfigurationMessage*>(p);
this->configure(m->configuration);
}
);
}
~FSKProcessor() {
message_handlers.unregister_handler(Message::ID::FSKConfiguration);
}
void configure(const FSKConfiguration new_configuration) {
demod.configure(76800, 2 * new_configuration.symbol_rate);
clock_recovery.configure(new_configuration.symbol_rate, 76800);
access_code_correlator.configure(
new_configuration.access_code,
new_configuration.access_code_length,
new_configuration.access_code_tolerance
);
packet_builder.configure(new_configuration.packet_length);
}
void execute(buffer_c8_t buffer) override {
/* 2.4576MHz, 2048 samples */
auto decimator_out = decimator.execute(buffer);
/* 153.6kHz, 128 samples */
const buffer_c16_t work_baseband_buffer {
(complex16_t*)decimator_out.p,
decimator_out.count
};
/* 153.6kHz complex<int16_t>[128]
* -> FIR filter, <?kHz (?fs) pass, gain 1.0
* -> 76.8kHz int16_t[64] */
auto channel = channel_filter.execute(decimator_out, work_baseband_buffer);
/* 76.8kHz, 64 samples */
feed_channel_stats(channel);
feed_channel_spectrum(
channel,
decimator_out.sampling_rate * channel_filter_taps.pass_frequency_normalized,
decimator_out.sampling_rate * channel_filter_taps.stop_frequency_normalized
);
const auto symbol_handler_fn = [this](const float value) {
const uint_fast8_t symbol = (value >= 0.0f) ? 1 : 0;
const bool access_code_found = this->access_code_correlator.execute(symbol);
this->consume_symbol(symbol, access_code_found);
};
// 76.8k
const buffer_s16_t work_demod_buffer {
(int16_t*)decimator_out.p,
decimator_out.count * sizeof(*decimator_out.p) / sizeof(int16_t)
};
auto demodulated = demod.execute(channel, work_demod_buffer);
i2s::i2s0::tx_mute();
for(size_t i=0; i<demodulated.count; i++) {
clock_recovery.execute(demodulated.p[i], symbol_handler_fn);
}
}
private:
ChannelDecimator decimator { ChannelDecimator::DecimationFactor::By16 };
const fir_taps_real<64>& channel_filter_taps = taps_64_lp_031_070_tfilter;
dsp::decimate::FIRAndDecimateBy2Complex<64> channel_filter { channel_filter_taps.taps };
dsp::demodulate::FM demod { 76800, 9600 * 2 };
ClockRecovery clock_recovery;
AccessCodeCorrelator access_code_correlator;
PacketBuilder packet_builder;
MessageHandlerMap& message_handlers;
void consume_symbol(
const uint_fast8_t symbol,
const bool access_code_found
) {
const auto payload_handler_fn = [this](
const std::bitset<256>& payload,
const size_t bits_received
) {
this->payload_handler(payload, bits_received);
};
packet_builder.execute(
symbol,
access_code_found,
payload_handler_fn
);
}
void payload_handler(
const std::bitset<256>& payload,
const size_t bits_received
) {
FSKPacketMessage message;
message.packet.payload = payload;
message.packet.bits_received = bits_received;
shared_memory.application_queue.push(message);
}
};
static BasebandProcessor* baseband_processor { nullptr };
static BasebandConfiguration baseband_configuration;
static WORKING_AREA(baseband_thread_wa, 8192);
static __attribute__((noreturn)) msg_t baseband_fn(void *arg) {
(void)arg;
chRegSetThreadName("baseband");
BasebandStatsCollector stats;
while(true) {
// TODO: Place correct sampling rate into buffer returned here:
const auto buffer_tmp = baseband::dma::wait_for_rx_buffer();
const buffer_c8_t buffer {
buffer_tmp.p, buffer_tmp.count, baseband_configuration.sampling_rate
};
if( baseband_processor ) {
baseband_processor->execute(buffer);
}
stats.process(buffer,
[](const BasebandStatistics statistics) {
BasebandStatisticsMessage message;
message.statistics = statistics;
shared_memory.application_queue.push(message);
}
);
}
}
static WORKING_AREA(rssi_thread_wa, 128);
static __attribute__((noreturn)) msg_t rssi_fn(void *arg) {
(void)arg;
chRegSetThreadName("rssi");
RSSIStatisticsCollector stats;
while(true) {
// TODO: Place correct sampling rate into buffer returned here:
const auto buffer_tmp = rf::rssi::dma::wait_for_buffer();
const rf::rssi::buffer_t buffer {
buffer_tmp.p, buffer_tmp.count, 400000
};
stats.process(
buffer,
[](const RSSIStatistics statistics) {
RSSIStatisticsMessage message;
message.statistics = statistics;
shared_memory.application_queue.push(message);
}
);
}
}
extern "C" {
void __late_init(void) {
/*
* System initializations.
* - HAL initialization, this also initializes the configured device drivers
* and performs the board-specific initializations.
* - Kernel initialization, the main() function becomes a thread and the
* RTOS is active.
*/
halInit();
/* After this call, scheduler, systick, heap, etc. are available. */
/* By doing chSysInit() here, it runs before C++ constructors, which may
* require the heap.
*/
chSysInit();
}
}
static void init() {
i2s::i2s0::configure(
audio::i2s0_config_tx,
audio::i2s0_config_rx,
audio::i2s0_config_dma
);
audio::dma::init();
audio::dma::configure();
audio::dma::enable();
i2s::i2s0::tx_start();
i2s::i2s0::rx_start();
LPC_CREG->DMAMUX = portapack::gpdma_mux;
gpdma::controller.enable();
nvicEnableVector(DMA_IRQn, CORTEX_PRIORITY_MASK(LPC_DMA_IRQ_PRIORITY));
baseband::dma::init();
rf::rssi::init();
touch::dma::init();
chThdCreateStatic(baseband_thread_wa, sizeof(baseband_thread_wa),
baseband_thread_priority, baseband_fn,
nullptr
);
chThdCreateStatic(rssi_thread_wa, sizeof(rssi_thread_wa),
rssi_thread_priority, rssi_fn,
nullptr
);
}
static void shutdown() {
// TODO: Is this complete?
nvicDisableVector(DMA_IRQn);
m0apptxevent_interrupt_disable();
chSysDisable();
systick_stop();
}
class EventDispatcher {
public:
MessageHandlerMap& message_handlers() {
return message_map;
}
void run() {
while(is_running) {
const auto events = wait();
dispatch(events);
}
}
void request_stop() {
is_running = false;
}
private:
MessageHandlerMap message_map;
bool is_running = true;
eventmask_t wait() {
return chEvtWaitAny(ALL_EVENTS);
}
void dispatch(const eventmask_t events) {
if( events & EVT_MASK_BASEBAND ) {
handle_baseband_queue();
}
if( events & EVT_MASK_SPECTRUM ) {
handle_spectrum();
}
}
void handle_baseband_queue() {
while( !shared_memory.baseband_queue.is_empty() ) {
std::array<uint8_t, Message::MAX_SIZE> message_buffer;
const Message* const message = reinterpret_cast<Message*>(message_buffer.data());
const auto message_size = shared_memory.baseband_queue.pop(message_buffer.data(), message_buffer.size());
if( message_size ) {
message_map.send(message);
}
}
}
void handle_spectrum() {
if( channel_spectrum_request_update ) {
/* Decimated buffer is full. Compute spectrum. */
std::array<std::complex<float>, channel_spectrum.size()> samples_swapped;
fft_swap(channel_spectrum, samples_swapped);
channel_spectrum_request_update = false;
fft_c_preswapped(samples_swapped);
ChannelSpectrumMessage spectrum_message;
for(size_t i=0; i<spectrum_message.spectrum.db.size(); i++) {
const auto mag2 = magnitude_squared(samples_swapped[i]);
const float db = complex16_mag_squared_to_dbv_norm(mag2);
constexpr float mag_scale = 5.0f;
const unsigned int v = (db * mag_scale) + 255.0f;
spectrum_message.spectrum.db[i] = std::max(0U, std::min(255U, v));
}
/* TODO: Rename .db -> .magnitude, or something more (less!) accurate. */
spectrum_message.spectrum.db_count = spectrum_message.spectrum.db.size();
spectrum_message.spectrum.sampling_rate = channel_spectrum_sampling_rate;
spectrum_message.spectrum.channel_filter_pass_frequency = channel_filter_pass_frequency;
spectrum_message.spectrum.channel_filter_stop_frequency = channel_filter_stop_frequency;
shared_memory.application_queue.push(spectrum_message);
}
}
};
static constexpr auto direction = baseband::Direction::Receive;
int main(void) {
init();
events_initialize(chThdSelf());
m0apptxevent_interrupt_enable();
EventDispatcher event_dispatcher;
auto& message_handlers = event_dispatcher.message_handlers();
message_handlers.register_handler(Message::ID::BasebandConfiguration,
[&message_handlers](const Message* const p) {
auto message = reinterpret_cast<const BasebandConfigurationMessage*>(p);
if( message->configuration.mode != baseband_configuration.mode ) {
// TODO: Timing problem around disabling DMA and nulling and deleting old processor
auto old_p = baseband_processor;
baseband_processor = nullptr;
delete old_p;
switch(message->configuration.mode) {
case 0:
baseband_processor = new NarrowbandAMAudio();
break;
case 1:
baseband_processor = new NarrowbandFMAudio();
break;
case 2:
baseband_processor = new WidebandFMAudio();
break;
case 3:
baseband_processor = new FSKProcessor(message_handlers);
break;
default:
break;
}
if( baseband_processor ) {
if( direction == baseband::Direction::Receive ) {
rf::rssi::start();
}
baseband::dma::enable(direction);
} else {
baseband::dma::disable();
rf::rssi::stop();
}
}
baseband_configuration = message->configuration;
}
);
message_handlers.register_handler(Message::ID::Shutdown,
[&event_dispatcher](const Message* const) {
event_dispatcher.request_stop();
}
);
/* TODO: Ensure DMAs are configured to point at first LLI in chain. */
if( direction == baseband::Direction::Receive ) {
rf::rssi::dma::allocate(4, 400);
}
touch::dma::allocate();
touch::dma::enable();
const auto baseband_buffer =
new std::array<baseband::sample_t, 8192>();
baseband::dma::configure(
baseband_buffer->data(),
direction
);
//baseband::dma::allocate(4, 2048);
event_dispatcher.run();
shutdown();
ShutdownMessage shutdown_message;
shared_memory.application_queue.push(shutdown_message);
return 0;
}