mayhem-firmware/firmware/baseband/proc_fsk.cpp

/*
 * Copyright (C) 2014 Jared Boone, ShareBrained Technology, Inc.
 * Copyright (C) 2016 Furrtek
 *
 * 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 "proc_fsk.hpp"
#include "portapack_shared_memory.hpp"
#include "sine_table_int8.hpp"
#include "event_m4.hpp"

#include <cstdint>

void FSKProcessor::execute(const buffer_c8_t& buffer) {
    int8_t re, im;

    // This is called at 2.28M/2048 = 1113Hz

    for (size_t i = 0; i < buffer.count; i++) {
        if (configured) {
            if (sample_count >= samples_per_bit) {
                if (bit_pos > length) {
                    // End of data
                    cur_bit = 0;
                    txprogress_message.done = true;
                    shared_memory.application_queue.push(txprogress_message);
                    configured = false;
                } else {
                    cur_bit = (shared_memory.bb_data.data[bit_pos >> 3] << (bit_pos & 7)) & 0x80;
                    bit_pos++;
                    if (progress_count >= progress_notice) {
                        progress_count = 0;
                        txprogress_message.progress++;
                        txprogress_message.done = false;
                        shared_memory.application_queue.push(txprogress_message);
                    } else {
                        progress_count++;
                    }
                }
                sample_count = 0;
            } else {
                sample_count++;
            }

            if (cur_bit)
                phase += shift_one;
            else
                phase += shift_zero;

            sphase = phase + (64 << 24);

            re = (sine_table_i8[(sphase & 0xFF000000) >> 24]);
            im = (sine_table_i8[(phase & 0xFF000000) >> 24]);
        } else {
            re = 0;
            im = 0;
        }

        buffer.p[i] = {re, im};
    }
}

void FSKProcessor::on_message(const Message* const p) {
    const auto message = *reinterpret_cast<const FSKConfigureMessage*>(p);

    if (message.id == Message::ID::FSKConfigure) {
        samples_per_bit = message.samples_per_bit;
        length = message.stream_length + 32;  // Why ?!

        shift_one = message.shift * (0xFFFFFFFFULL / 2280000);
        shift_zero = -shift_one;

        progress_notice = message.progress_notice;

        sample_count = samples_per_bit;
        progress_count = 0;
        bit_pos = 0;
        cur_bit = 0;

        txprogress_message.progress = 0;
        txprogress_message.done = false;
        configured = true;
    }
}

int main() {
    EventDispatcher event_dispatcher{std::make_unique<FSKProcessor>()};
    event_dispatcher.run();
    return 0;
}