mirror of
https://github.com/portapack-mayhem/mayhem-firmware.git
synced 2024-12-13 11:44:31 +00:00
187 lines
6.3 KiB
C++
187 lines
6.3 KiB
C++
/*
|
|
* Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
|
|
* Copyright (C) 2017 Furrtek
|
|
* Copyright (C) 2014 zilog80
|
|
*
|
|
* 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.
|
|
*/
|
|
|
|
/* Notes to self (or others, welcome !):
|
|
* Sharebrained wrote in matched_filter.hpp that taps should be those of a complex low-pass filter combined with a complex sinusoid, so
|
|
* that the filter shifts the spectrum where we want (signal of interest around 0Hz).
|
|
*
|
|
* In this baseband processor, after decim_0 and decim_1, the signal ends up being sampled at 38400Hz (2457600 / 8 / 8)
|
|
* Since the applied shift in ui_sonde.cpp is -fs/4 = -2457600/4 = -614400Hz to avoid the DC spike, the FSK signal ends up being
|
|
* shifted by 614400 / 8 / 8 = 9600Hz. So decim_1_out should look like this:
|
|
*
|
|
* _______________|______/'\______
|
|
* -C A B C
|
|
*
|
|
* A is the DC spike at 0Hz
|
|
* B is the FSK signal shifted right at 9600Hz
|
|
* C is the bandwidth edge at 19200Hz
|
|
*
|
|
* Taps should be computed to shift the whole spectrum by -9600Hz ("left") so that it looks like this:
|
|
*
|
|
* ______________/'\______________
|
|
* -C D C
|
|
*
|
|
* Anything unwanted (like A) should have been filtered off
|
|
* D is B around 0Hz now
|
|
*
|
|
* Then the clock_recovery function should be happy :)
|
|
*
|
|
* Mathworks.com says:
|
|
* In the case of a single-rate FIR design, we simply multiply each set of coefficients by (aka 'heterodyne with') a complex exponential.
|
|
*
|
|
* Can SciPy's remez function be used for this ? See tools/firtest.py
|
|
* GnuRadio's firdes only outputs an odd number of taps
|
|
*
|
|
* ---------------------------------------------------------------------
|
|
*
|
|
* Looking at the AIS baseband processor:
|
|
*
|
|
* Copied everything necessary to get decim_1_out (so same 8 * 8 = 64 decimation factor)
|
|
* The samplerate is also the same (2457600)
|
|
* After the matching filter, the data is decimated by 2 so the final samplerate for clock_recovery is 38400 / 2 = 19200Hz.
|
|
* Like here, the shift used is fs/4, so decim_1_out should be looking similar.
|
|
* The AIS signal deviates by 2400 (4800Hz signal width), the symbol rate is 9600.
|
|
*
|
|
* The matched filter's input samplerate is 38400Hz, to get a 9600Hz shift it must use 4 taps ?
|
|
* To obtain unity gain, the sinusoid length must be / by the number of taps ?
|
|
*
|
|
* See ais_baseband.hpp
|
|
*
|
|
* */
|
|
|
|
#ifndef __PROC_SONDE_H__
|
|
#define __PROC_SONDE_H__
|
|
|
|
#include "baseband_processor.hpp"
|
|
#include "baseband_thread.hpp"
|
|
#include "rssi_thread.hpp"
|
|
#include "proc_ais.hpp"
|
|
|
|
#include "channel_decimator.hpp"
|
|
#include "matched_filter.hpp"
|
|
|
|
#include "clock_recovery.hpp"
|
|
#include "symbol_coding.hpp"
|
|
#include "packet_builder.hpp"
|
|
#include "baseband_packet.hpp"
|
|
|
|
#include "message.hpp"
|
|
#include "portapack_shared_memory.hpp"
|
|
|
|
#include "audio_output.hpp"
|
|
#include "tone_gen.hpp"
|
|
#include "tonesets.hpp"
|
|
#include "sine_table_int8.hpp"
|
|
|
|
#include "buffer.hpp"
|
|
|
|
#include <cstdint>
|
|
#include <cstddef>
|
|
#include <bitset>
|
|
|
|
class SondeProcessor : public BasebandProcessor {
|
|
public:
|
|
SondeProcessor();
|
|
|
|
void execute(const buffer_c8_t& buffer) override;
|
|
void on_message(const Message* const msg);
|
|
private:
|
|
|
|
static constexpr size_t baseband_fs = 2457600;
|
|
static constexpr size_t beep_iterations = 60;
|
|
|
|
std::array<int16_t, 16> audio { };
|
|
|
|
const buffer_s16_t audio_buffer {
|
|
(int16_t*) audio.data(),
|
|
sizeof(audio) / sizeof(int16_t)
|
|
};
|
|
|
|
AudioOutput audio_output { };
|
|
|
|
bool beep_playing { false };
|
|
bool pitch_rssi_enabled { false };
|
|
|
|
uint32_t tone_delta { 0 };
|
|
uint32_t tone_phase { 0 };
|
|
|
|
BasebandThread baseband_thread { baseband_fs, this, NORMALPRIO + 20, baseband::Direction::Receive };
|
|
RSSIThread rssi_thread { NORMALPRIO + 10 };
|
|
|
|
std::array<complex16_t, 512> dst { };
|
|
const buffer_c16_t dst_buffer {
|
|
dst.data(),
|
|
dst.size()
|
|
};
|
|
|
|
dsp::decimate::FIRC8xR16x24FS4Decim8 decim_0 { };
|
|
dsp::decimate::FIRC16xR16x32Decim8 decim_1 { };
|
|
dsp::matched_filter::MatchedFilter mf { baseband::ais::square_taps_38k4_1t_p, 2 };
|
|
|
|
// Actually 4800bits/s but the Manchester coding doubles the symbol rate
|
|
clock_recovery::ClockRecovery<clock_recovery::FixedErrorFilter> clock_recovery_fsk_9600 {
|
|
19200, 9600, { 0.0555f },
|
|
[this](const float raw_symbol) {
|
|
const uint_fast8_t sliced_symbol = (raw_symbol >= 0.0f) ? 1 : 0;
|
|
this->packet_builder_fsk_9600_Meteomodem.execute(sliced_symbol);
|
|
}
|
|
};
|
|
PacketBuilder<BitPattern, NeverMatch, FixedLength> packet_builder_fsk_9600_Meteomodem {
|
|
{ 0b00110011001100110101100110110011, 32, 1 },
|
|
{ },
|
|
{ 88 * 2 * 8 },
|
|
[this](const baseband::Packet& packet) {
|
|
const SondePacketMessage message { sonde::Packet::Type::Meteomodem_unknown, packet };
|
|
shared_memory.application_queue.push(message);
|
|
}
|
|
};
|
|
|
|
clock_recovery::ClockRecovery<clock_recovery::FixedErrorFilter> clock_recovery_fsk_4800 {
|
|
19200, 4800, { 0.0555f },
|
|
[this](const float raw_symbol) {
|
|
const uint_fast8_t sliced_symbol = (raw_symbol >= 0.0f) ? 1 : 0;
|
|
this->packet_builder_fsk_4800_Vaisala.execute(sliced_symbol);
|
|
}
|
|
};
|
|
PacketBuilder<BitPattern, NeverMatch, FixedLength> packet_builder_fsk_4800_Vaisala {
|
|
{ 0b00001000011011010101001110001000, 32, 1 }, //euquiq Header detects 4 of 8 bytes 0x10B6CA11 /this is in raw format) (these bits are not passed at the beginning of packet)
|
|
//{ 0b0000100001101101010100111000100001000100011010010100100000011111, 64, 1 }, //euquiq whole header detection would be 8 bytes.
|
|
{ },
|
|
{ 320 * 8 },
|
|
[this](const baseband::Packet& packet) {
|
|
const SondePacketMessage message { sonde::Packet::Type::Vaisala_RS41_SG, packet };
|
|
shared_memory.application_queue.push(message);
|
|
}
|
|
};
|
|
|
|
void play_beep();
|
|
void stop_beep();
|
|
|
|
void beep_loop();
|
|
void silence_loop();
|
|
|
|
void pitch_rssi_config(const PitchRSSIConfigureMessage& message);
|
|
};
|
|
|
|
#endif/*__PROC_ERT_H__*/
|