mayhem-firmware/firmware/baseband/proc_afsk.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_afsk.hpp"
#include "portapack_shared_memory.hpp"
#include "sine_table_int8.hpp"
#include "event_m4.hpp"

#include <cstdint>

void AFSKProcessor::execute(const buffer_c8_t& buffer) {
    // This is called at 2.28M/2048 = 1113Hz

    if (!configured) return;

    for (size_t i = 0; i < buffer.count; i++) {
        if (sample_count >= afsk_samples_per_bit) {
            if (configured) {
                cur_word = *word_ptr;

                if (!cur_word) {
                    // End of data
                    if (repeat_counter < afsk_repeat) {
                        // Repeat
                        bit_pos = 0;
                        word_ptr = (uint16_t*)shared_memory.bb_data.data;
                        cur_word = *word_ptr;
                        txprogress_message.done = false;
                        txprogress_message.progress = repeat_counter + 1;
                        shared_memory.application_queue.push(txprogress_message);
                        repeat_counter++;
                    } else {
                        // Stop
                        cur_word = 0;
                        txprogress_message.done = true;
                        shared_memory.application_queue.push(txprogress_message);
                        configured = false;
                    }
                }
            }

            cur_bit = (cur_word >> (symbol_count - bit_pos)) & 1;

            if (bit_pos >= symbol_count) {
                bit_pos = 0;
                word_ptr++;
            } else {
                bit_pos++;
            }

            sample_count = 0;
        } else {
            sample_count++;
        }

        if (cur_bit)
            tone_phase += afsk_phase_inc_mark;
        else
            tone_phase += afsk_phase_inc_space;

        tone_sample = sine_table_i8[(tone_phase & 0xFF000000U) >> 24];

        delta = tone_sample * fm_delta;

        phase += delta;
        sphase = phase + (64 << 24);

        re = (sine_table_i8[(sphase & 0xFF000000U) >> 24]);
        im = (sine_table_i8[(phase & 0xFF000000U) >> 24]);

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

void AFSKProcessor::on_message(const Message* const msg) {
    const auto message = *reinterpret_cast<const AFSKTxConfigureMessage*>(msg);

    if (message.id == Message::ID::AFSKTxConfigure) {
        if (message.samples_per_bit) {
            afsk_samples_per_bit = message.samples_per_bit;
            afsk_phase_inc_mark = message.phase_inc_mark * AFSK_DELTA_COEF;
            afsk_phase_inc_space = message.phase_inc_space * AFSK_DELTA_COEF;
            afsk_repeat = message.repeat - 1;
            fm_delta = message.fm_delta * (0xFFFFFFULL / AFSK_SAMPLERATE);
            symbol_count = message.symbol_count - 1;

            sample_count = afsk_samples_per_bit;
            repeat_counter = 0;
            bit_pos = 0;
            word_ptr = (uint16_t*)shared_memory.bb_data.data;
            cur_word = 0;
            cur_bit = 0;
            configured = true;
        } else
            configured = false;  // Kill
    }
}

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