portapack-mayhem/firmware/baseband/proc_tpms.hpp

/*
 * Copyright (C) 2015 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2023 Mark Thompson
 *
 * 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.
 */

#ifndef __PROC_TPMS_H__
#define __PROC_TPMS_H__

#include "baseband_processor.hpp"
#include "baseband_thread.hpp"
#include "rssi_thread.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 "ook.hpp"

#include "message.hpp"
#include "portapack_shared_memory.hpp"

#include <cstdint>
#include <cstddef>
#include <bitset>

// Translate+rectangular filter
// sample=307.2k, deviation=38400, symbol=19200
// Length: 16 taps, 1 symbols, 2 cycles of sinusoid
constexpr std::array<std::complex<float>, 16> rect_taps_307k2_38k4_1t_19k2_p{{
    {6.2500000000e-02f, 0.0000000000e+00f},
    {4.4194173824e-02f, 4.4194173824e-02f},
    {0.0000000000e+00f, 6.2500000000e-02f},
    {-4.4194173824e-02f, 4.4194173824e-02f},
    {-6.2500000000e-02f, 0.0000000000e+00f},
    {-4.4194173824e-02f, -4.4194173824e-02f},
    {0.0000000000e+00f, -6.2500000000e-02f},
    {4.4194173824e-02f, -4.4194173824e-02f},
    {6.2500000000e-02f, 0.0000000000e+00f},
    {4.4194173824e-02f, 4.4194173824e-02f},
    {0.0000000000e+00f, 6.2500000000e-02f},
    {-4.4194173824e-02f, 4.4194173824e-02f},
    {-6.2500000000e-02f, 0.0000000000e+00f},
    {-4.4194173824e-02f, -4.4194173824e-02f},
    {0.0000000000e+00f, -6.2500000000e-02f},
    {4.4194173824e-02f, -4.4194173824e-02f},
}};

class TPMSProcessor : public BasebandProcessor {
   public:
    TPMSProcessor();

    void execute(const buffer_c8_t& buffer) override;

   private:
    static constexpr size_t baseband_fs = 2457600;

    std::array<complex16_t, 512> dst{};
    const buffer_c16_t dst_buffer{
        dst.data(),
        dst.size()};

    dsp::decimate::FIRC8xR16x24FS4Decim4 decim_0{};
    dsp::decimate::FIRC16xR16x16Decim2 decim_1{};

    dsp::matched_filter::MatchedFilter mf_38k4_1t_19k2{rect_taps_307k2_38k4_1t_19k2_p, 8};

    clock_recovery::ClockRecovery<clock_recovery::FixedErrorFilter> clock_recovery_fsk_19k2{
        38400,
        19200,
        {0.0555f},
        [this](const float raw_symbol) {
            const uint_fast8_t sliced_symbol = (raw_symbol >= 0.0f) ? 1 : 0;
            this->packet_builder_fsk_19k2_schrader.execute(sliced_symbol);
        }};
    PacketBuilder<BitPattern, NeverMatch, FixedLength> packet_builder_fsk_19k2_schrader{
        {0b010101010101010101010101010110, 30, 1},
        {},
        {160},
        [this](const baseband::Packet& packet) {
            const TPMSPacketMessage message{tpms::SignalType::FSK_19k2_Schrader, packet};
            shared_memory.application_queue.push(message);
        }};

    static constexpr float channel_rate_in = 307200.0f;
    static constexpr size_t channel_decimation = 2;
    static constexpr float channel_sample_rate = channel_rate_in / channel_decimation;
    OOKSlicerMagSquaredInt ook_slicer_5sps{channel_sample_rate / 8400 + 1};
    uint32_t slicer_history{0};

    OOKClockRecovery clock_recovery_ook_8k192{
        channel_sample_rate / 8192.0f};

    PacketBuilder<BitPattern, NeverMatch, FixedLength> packet_builder_ook_8k192_schrader{
        /* Preamble: 11*2, 01*14, 11, 10
         * Payload: 37 Manchester-encoded bits
         * Bit rate: 4096 Hz
         */
        {0b010101010101010101011110, 24, 0},
        {},
        {37 * 2},
        [](const baseband::Packet& packet) {
            const TPMSPacketMessage message{tpms::SignalType::OOK_8k192_Schrader, packet};
            shared_memory.application_queue.push(message);
        }};

    OOKClockRecovery clock_recovery_ook_8k4{
        channel_sample_rate / 8400.0f};

    PacketBuilder<BitPattern, NeverMatch, FixedLength> packet_builder_ook_8k4_schrader{
        /* Preamble: 01*40, 01, 10, 01, 01
         * Payload: 76 Manchester-encoded bits
         * Bit rate: 4200 Hz
         */
        {0b01010101010101010101010101100101, 32, 0},
        {},
        {76 * 2},
        [](const baseband::Packet& packet) {
            const TPMSPacketMessage message{tpms::SignalType::OOK_8k4_Schrader, packet};
            shared_memory.application_queue.push(message);
        }};

    /* NB: Threads should be the last members in the class definition. */
    BasebandThread baseband_thread{
        baseband_fs, this, baseband::Direction::Receive, /*auto_start*/ false};
    RSSIThread rssi_thread{};
};

#endif /*__PROC_TPMS_H__*/